[v6.1] INFO: task hung in exit_mmap (3)
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syzbot
Jun 17, 2025, 1:04:30 AM6/17/25
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 58485ff1a74f Linux 6.1.141
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1277c90c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c186557a18643a0b
dashboard link: https://syzkaller.appspot.com/bug?extid=4ae44039c268079df003
compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/50f937e6976c/disk-58485ff1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/32fbd75d9fae/vmlinux-58485ff1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/56b5a2c82bda/bzImage-58485ff1.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4ae440...@syzkaller.appspotmail.com
INFO: task syz.0.11456:5394 blocked for more than 143 seconds.
Not tainted 6.1.141-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.11456 state:D stack:25440 pid:5394 ppid:4255 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10e9/0x40d0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
exit_mmap+0x20f/0x8e0 mm/mmap.c:3246
__mmput+0x118/0x3c0 kernel/fork.c:1200
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_exit+0x8b9/0x2400 kernel/exit.c:858
do_group_exit+0x217/0x2d0 kernel/exit.c:1021
__do_sys_exit_group kernel/exit.c:1032 [inline]
__se_sys_exit_group kernel/exit.c:1030 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1030
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f980118e929
RSP: 002b:00007ffdc59feab8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f980118e929
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffdc59feb1c R08: 0000001cc59febaf R09: 00000000000927c0
R10: 00000000000014bc R11: 0000000000000246 R12: 00000000000008cf
R13: 00000000000927c0 R14: 000000000018df9c R15: 00007ffdc59feb70
</TASK>
INFO: task syz.3.11460:5406 blocked for more than 143 seconds.
Not tainted 6.1.141-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.11460 state:D stack:25352 pid:5406 ppid:4250 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10e9/0x40d0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
exit_mmap+0x20f/0x8e0 mm/mmap.c:3246
__mmput+0x118/0x3c0 kernel/fork.c:1200
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_exit+0x8b9/0x2400 kernel/exit.c:858
do_group_exit+0x217/0x2d0 kernel/exit.c:1021
get_signal+0x1272/0x1350 kernel/signal.c:2871
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7faec4d8e929
RSP: 002b:00007faec5bbbfe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: fffffffffffffff4 RBX: 00007faec4fb5fa0 RCX: 00007faec4d8e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020083400
RBP: 00007faec4e10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007faec4fb5fa0 R15: 00007ffeb64d1638
</TASK>
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8c92b430 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8c92bc50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
1 lock held by syslogd/3605:
#0: ffff8880b8f3aa98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
2 locks held by getty/4011:
#0: ffff88802fe63098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000326b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/4239:
#0: ffff88807a06d3d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#0: ffff88807a06d3d8 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15d/0x2b0 mm/util.c:518
1 lock held by syz-executor/4255:
#0: ffff8880305062d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880305062d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3246
2 locks held by syz-executor/4259:
#0: ffffffff8c9c6c70 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap kernel/fork.c:593 [inline]
#0: ffffffff8c9c6c70 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline]
#0: ffffffff8c9c6c70 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x2a9/0x15c0 kernel/fork.c:1590
#1: ffff88807bf34c58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff88807bf34c58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:594 [inline]
#1: ffff88807bf34c58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1541 [inline]
#1: ffff88807bf34c58 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x2c3/0x15c0 kernel/fork.c:1590
2 locks held by syz-executor/4265:
#0: ffffffff8c9c6c70 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap kernel/fork.c:593 [inline]
#0: ffffffff8c9c6c70 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline]
#0: ffffffff8c9c6c70 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x2a9/0x15c0 kernel/fork.c:1590
#1: ffff88807bf35b58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff88807bf35b58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:594 [inline]
#1: ffff88807bf35b58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1541 [inline]
#1: ffff88807bf35b58 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x2c3/0x15c0 kernel/fork.c:1590
1 lock held by syz.0.11456/5394:
#0: ffff88802470cc58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88802470cc58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3246
1 lock held by syz.3.11460/5406:
#0: ffff888075b488d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888075b488d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3246
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
<TASK>
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 26574 Comm: kworker/u4:8 Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:insn_complete arch/x86/lib/insn.c:722 [inline]
RIP: 0010:insn_decode+0x347/0x520 arch/x86/lib/insn.c:751
Code: 03 42 0f b6 04 20 84 c0 0f 85 bd 01 00 00 41 0f b6 2e 31 ff 89 ee e8 98 ec 7c f7 85 ed 74 69 48 83 c3 3c 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 af 01 00 00 0f b6 03 0f b6 d8 31 ff 89
RSP: 0018:ffffc900042b78e8 EFLAGS: 00000a07
RAX: 1ffff92000856f33 RBX: ffffc900042b799c RCX: 0000000000000000
RDX: ffff88807cbf9dc0 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffff88807cbf9dc0 R09: 0000000000000003
R10: 0000000000000008 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff92000856f36 R14: ffffc900042b7994 R15: ffffc900042b79b8
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f38e8c00218 CR3: 000000007e20d000 CR4: 00000000003506e0
DR0: fffffffffffffffc DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<TASK>
arch_jump_entry_size arch/x86/kernel/jump_label.c:24 [inline]
__jump_label_patch+0xd8/0x430 arch/x86/kernel/jump_label.c:45
arch_jump_label_transform_queue+0x48/0xd0 arch/x86/kernel/jump_label.c:137
__jump_label_update+0x17d/0x390 kernel/jump_label.c:510
static_key_disable_cpuslocked+0xc1/0x1a0 kernel/jump_label.c:237
static_key_disable+0x16/0x20 kernel/jump_label.c:245
toggle_allocation_gate+0x38f/0x430 mm/kfence/core.c:819
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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If the report is already addressed, let syzbot know by replying with:
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(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
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If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: 58485ff1a74f Linux 6.1.141
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1277c90c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c186557a18643a0b
dashboard link: https://syzkaller.appspot.com/bug?extid=4ae44039c268079df003
compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/50f937e6976c/disk-58485ff1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/32fbd75d9fae/vmlinux-58485ff1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/56b5a2c82bda/bzImage-58485ff1.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4ae440...@syzkaller.appspotmail.com
INFO: task syz.0.11456:5394 blocked for more than 143 seconds.
Not tainted 6.1.141-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.11456 state:D stack:25440 pid:5394 ppid:4255 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10e9/0x40d0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
exit_mmap+0x20f/0x8e0 mm/mmap.c:3246
__mmput+0x118/0x3c0 kernel/fork.c:1200
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_exit+0x8b9/0x2400 kernel/exit.c:858
do_group_exit+0x217/0x2d0 kernel/exit.c:1021
__do_sys_exit_group kernel/exit.c:1032 [inline]
__se_sys_exit_group kernel/exit.c:1030 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1030
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f980118e929
RSP: 002b:00007ffdc59feab8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f980118e929
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffdc59feb1c R08: 0000001cc59febaf R09: 00000000000927c0
R10: 00000000000014bc R11: 0000000000000246 R12: 00000000000008cf
R13: 00000000000927c0 R14: 000000000018df9c R15: 00007ffdc59feb70
</TASK>
INFO: task syz.3.11460:5406 blocked for more than 143 seconds.
Not tainted 6.1.141-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.11460 state:D stack:25352 pid:5406 ppid:4250 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10e9/0x40d0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
exit_mmap+0x20f/0x8e0 mm/mmap.c:3246
__mmput+0x118/0x3c0 kernel/fork.c:1200
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_exit+0x8b9/0x2400 kernel/exit.c:858
do_group_exit+0x217/0x2d0 kernel/exit.c:1021
get_signal+0x1272/0x1350 kernel/signal.c:2871
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7faec4d8e929
RSP: 002b:00007faec5bbbfe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: fffffffffffffff4 RBX: 00007faec4fb5fa0 RCX: 00007faec4d8e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020083400
RBP: 00007faec4e10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007faec4fb5fa0 R15: 00007ffeb64d1638
</TASK>
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8c92b430 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8c92bc50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
1 lock held by syslogd/3605:
#0: ffff8880b8f3aa98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
2 locks held by getty/4011:
#0: ffff88802fe63098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000326b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/4239:
#0: ffff88807a06d3d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#0: ffff88807a06d3d8 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15d/0x2b0 mm/util.c:518
1 lock held by syz-executor/4255:
#0: ffff8880305062d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880305062d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3246
2 locks held by syz-executor/4259:
#0: ffffffff8c9c6c70 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap kernel/fork.c:593 [inline]
#0: ffffffff8c9c6c70 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline]
#0: ffffffff8c9c6c70 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x2a9/0x15c0 kernel/fork.c:1590
#1: ffff88807bf34c58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff88807bf34c58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:594 [inline]
#1: ffff88807bf34c58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1541 [inline]
#1: ffff88807bf34c58 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x2c3/0x15c0 kernel/fork.c:1590
2 locks held by syz-executor/4265:
#0: ffffffff8c9c6c70 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap kernel/fork.c:593 [inline]
#0: ffffffff8c9c6c70 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline]
#0: ffffffff8c9c6c70 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x2a9/0x15c0 kernel/fork.c:1590
#1: ffff88807bf35b58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff88807bf35b58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:594 [inline]
#1: ffff88807bf35b58 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1541 [inline]
#1: ffff88807bf35b58 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x2c3/0x15c0 kernel/fork.c:1590
1 lock held by syz.0.11456/5394:
#0: ffff88802470cc58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88802470cc58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3246
1 lock held by syz.3.11460/5406:
#0: ffff888075b488d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888075b488d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3246
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
<TASK>
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 26574 Comm: kworker/u4:8 Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:insn_complete arch/x86/lib/insn.c:722 [inline]
RIP: 0010:insn_decode+0x347/0x520 arch/x86/lib/insn.c:751
Code: 03 42 0f b6 04 20 84 c0 0f 85 bd 01 00 00 41 0f b6 2e 31 ff 89 ee e8 98 ec 7c f7 85 ed 74 69 48 83 c3 3c 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 af 01 00 00 0f b6 03 0f b6 d8 31 ff 89
RSP: 0018:ffffc900042b78e8 EFLAGS: 00000a07
RAX: 1ffff92000856f33 RBX: ffffc900042b799c RCX: 0000000000000000
RDX: ffff88807cbf9dc0 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffff88807cbf9dc0 R09: 0000000000000003
R10: 0000000000000008 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff92000856f36 R14: ffffc900042b7994 R15: ffffc900042b79b8
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f38e8c00218 CR3: 000000007e20d000 CR4: 00000000003506e0
DR0: fffffffffffffffc DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<TASK>
arch_jump_entry_size arch/x86/kernel/jump_label.c:24 [inline]
__jump_label_patch+0xd8/0x430 arch/x86/kernel/jump_label.c:45
arch_jump_label_transform_queue+0x48/0xd0 arch/x86/kernel/jump_label.c:137
__jump_label_update+0x17d/0x390 kernel/jump_label.c:510
static_key_disable_cpuslocked+0xc1/0x1a0 kernel/jump_label.c:237
static_key_disable+0x16/0x20 kernel/jump_label.c:245
toggle_allocation_gate+0x38f/0x430 mm/kfence/core.c:819
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot
Sep 11, 2025, 6:27:30 AM9/11/25
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:
HEAD commit: f97f1002271b Linux 6.1.151
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=117aab12580000
kernel config: https://syzkaller.appspot.com/x/.config?x=cc3aff322420b627
dashboard link: https://syzkaller.appspot.com/bug?extid=4ae44039c268079df003
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=141efd62580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1e5fcaa1f440/disk-f97f1002.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/543be75b6937/vmlinux-f97f1002.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5a416e3a0c42/bzImage-f97f1002.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4ae440...@syzkaller.appspotmail.com
INFO: task syz.4.21:4586 blocked for more than 143 seconds.
Not tainted syzkaller #0
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
RSP: 002b:00007fb6d91b20e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fb6d85d5fa8 RCX: 00007fb6d838eba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb6d85d5fa8
RBP: 00007fb6d85d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb6d85d6038 R14: 00007ffed993a3e0 R15: 00007ffed993a4c8
</TASK>
INFO: task syz.3.86:4662 blocked for more than 143 seconds.
Not tainted syzkaller #0
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
RSP: 002b:00007f112ad790e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f112a1d5fa8 RCX: 00007f1129f8eba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f112a1d5fa8
RBP: 00007f112a1d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f112a1d6038 R14: 00007ffd4a0e2cb0 R15: 00007ffd4a0e2d98
</TASK>
INFO: task syz.1.87:4661 blocked for more than 144 seconds.
Not tainted syzkaller #0
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
RSP: 002b:00007fa93e7ce0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fa93dbd5fa8 RCX: 00007fa93d98eba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa93dbd5fa8
RBP: 00007fa93dbd5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa93dbd6038 R14: 00007ffd98d65980 R15: 00007ffd98d65a68
#0: ffff8880b8f3aad8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
#1: ffff8880b8f27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x398/0x6d0 kernel/sched/psi.c:999
#2: ffff8880b8f28418 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:999
1 lock held by khungtaskd/28:
#0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by kworker/u4:3/51:
#0: ffff8880b8f3aad8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
#1: ffff8880b8f27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x398/0x6d0 kernel/sched/psi.c:999
2 locks held by udevd/3637:
#0: ffffffff8cbc4c50 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:593 [inline]
#0: ffffffff8cbc4c50 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline]
#0: ffffffff8cbc4c50 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x2a9/0x15c0 kernel/fork.c:1590
#1: ffff88807c1f9058 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff88807c1f9058 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:594 [inline]
#1: ffff88807c1f9058 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1541 [inline]
#1: ffff88807c1f9058 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x2c3/0x15c0 kernel/fork.c:1590
1 lock held by dhcpcd/3932:
#0: ffffffff8cb53610 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: copy_process+0x248b/0x4020 kernel/fork.c:2446
2 locks held by getty/4031:
#0: ffff88802fc87098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/4397:
#0: ffff8880174688d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880174688d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4399:
#0: ffff88801746b5d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88801746b5d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4400:
#0: ffff8880274b9058 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880274b9058 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4407:
#0: ffff8880274b8158 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880274b8158 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4409:
#0: ffff8880769f17d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880769f17d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.4.21/4586:
#0: ffff88807caf62d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88807caf62d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.3.86/4662:
#0: ffff8880273bf958 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880273bf958 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.1.87/4661:
#0: ffff8880273b8158 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880273b8158 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.0.88/4663:
#0: ffff8880273b9f58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880273b9f58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
2 locks held by syz-executor/4665:
#0: ffffffff8cbc4c50 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:593 [inline]
#0: ffffffff8cbc4c50 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline]
#0: ffffffff8cbc4c50 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x2a9/0x15c0 kernel/fork.c:1590
#1: ffff8880273b88d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff8880273b88d8 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:594 [inline]
#1: ffff8880273b88d8 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1541 [inline]
#1: ffff8880273b88d8 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x2c3/0x15c0 kernel/fork.c:1590
1 lock held by syz-executor/4680:
#0: ffffffff8cb53610 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x578/0x2400 kernel/exit.c:827
7 locks held by syz-executor/4707:
#0: ffff8880196b6460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580
#1: ffff888028204088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:325
#2: ffffffff8cb53428 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:442 [inline]
#2: ffffffff8cb53428 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1677
#3: ffffffff8c9c7870 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2453 [inline]
#3: ffffffff8c9c7870 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x183/0x600 kernel/cgroup/cgroup.c:2959
#4: ffffffff8cb53610 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2455 [inline]
#4: ffffffff8cb53610 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x199/0x600 kernel/cgroup/cgroup.c:2959
#5: ffffffff8cb619a8 (cpuset_mutex){+.+.}-{3:3}, at: cpuset_attach+0xac/0x540 kernel/cgroup/cpuset.c:2647
#6: ffff8880273bd3d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#6: ffff8880273bd3d8 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0xbe/0x370 mm/mempolicy.c:386
3 locks held by syz-executor/4710:
#0: ffff88807a79e460 (sb_writers#10){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:393
#1: ffff88806e009080 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
#1: ffff88806e009080 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: filename_create+0x1f2/0x450 fs/namei.c:3876
#2: ffffffff8cb53428 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:442 [inline]
#2: ffffffff8cb53428 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1677
2 locks held by syz-executor/4717:
#0: ffff88807a79e460 (sb_writers#10){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:393
#1: ffff88806e009080 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
#1: ffff88806e009080 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: filename_create+0x1f2/0x450 fs/namei.c:3876
1 lock held by syz.6.148/4864:
#0: ffff88807c1fe2d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88807c1fe2d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:poke_int3_handler+0x170/0x1d0 arch/x86/kernel/alternative.c:1700
Code: 48 89 87 80 00 00 00 b8 01 00 00 00 f0 ff 0d 13 cd 77 05 c3 81 c6 3d ff ff ff 83 fe 28 77 5b ff 24 f5 40 75 86 8a 48 63 40 04 <eb> d1 31 c0 f0 ff 0d f1 cc 77 05 c3 48 8b 8f 98 00 00 00 48 8b 01
RSP: 0018:ffffc90001577998 EFLAGS: 00000093
RAX: 000000000000022a RBX: ffffc900015779b8 RCX: ffffffff81d0228f
RDX: ffffffff81d0228b RSI: 0000000000000026 RDI: ffffc900015779b8
RBP: 0000000000000000 R08: 0000000000000079 R09: ffffffff8f8edcd0
R10: ffffffff81d0228a R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
exc_int3+0xa/0x70 arch/x86/kernel/traps.c:827
asm_exc_int3+0x35/0x40 arch/x86/include/asm/idtentry.h:607
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline]
RIP: 0010:kfence_alloc include/linux/kfence.h:120 [inline]
RIP: 0010:slab_alloc_node mm/slub.c:3283 [inline]
RIP: 0010:kmem_cache_alloc_node+0x6b/0x320 mm/slub.c:3404
Code: 00 00 00 31 db 48 8d 54 24 10 b9 01 00 00 00 31 f6 45 89 f0 e8 46 13 00 00 48 85 c0 0f 84 ef 00 00 00 49 89 c5 4c 89 24 24 cc <1f> 44 00 00 49 8b 45 00 65 48 03 05 0d f7 31 7e 48 8b 50 08 4c 8b
RSP: 0018:ffffc90001577a98 EFLAGS: 00000286
RAX: ffff8881401e5500 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 00000000000000f0 RDI: ffffffff8cc1cdc0
RBP: 00000000ffffffff R08: 0000000000000a20 R09: fffffbfff215c468
R10: fffffbfff215c468 R11: 1ffffffff215c467 R12: 00000000000000f0
R13: ffff8881401e5500 R14: 0000000000000a20 R15: ffff8881401e5500
__alloc_skb+0xfc/0x7e0 net/core/skbuff.c:505
alloc_skb include/linux/skbuff.h:1271 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x28f/0xaf0 drivers/net/netdevsim/dev.c:851
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
HEAD commit: f97f1002271b Linux 6.1.151
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=117aab12580000
kernel config: https://syzkaller.appspot.com/x/.config?x=cc3aff322420b627
dashboard link: https://syzkaller.appspot.com/bug?extid=4ae44039c268079df003
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=141efd62580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1e5fcaa1f440/disk-f97f1002.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/543be75b6937/vmlinux-f97f1002.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5a416e3a0c42/bzImage-f97f1002.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4ae440...@syzkaller.appspotmail.com
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.21 state:D stack:25728 pid:4586 ppid:4407 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
schedule+0xb9/0x180 kernel/sched/core.c:6637
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
__mmput+0x118/0x3c0 kernel/fork.c:1200
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_exit+0x8c1/0x2400 kernel/exit.c:867
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
get_signal+0x1272/0x1350 kernel/signal.c:2871
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb6d838eba9
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RSP: 002b:00007fb6d91b20e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fb6d85d5fa8 RCX: 00007fb6d838eba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb6d85d5fa8
RBP: 00007fb6d85d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb6d85d6038 R14: 00007ffed993a3e0 R15: 00007ffed993a4c8
</TASK>
INFO: task syz.3.86:4662 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.86 state:D stack:25696 pid:4662 ppid:4409 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
schedule+0xb9/0x180 kernel/sched/core.c:6637
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
__mmput+0x118/0x3c0 kernel/fork.c:1200
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_exit+0x8c1/0x2400 kernel/exit.c:867
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
get_signal+0x1272/0x1350 kernel/signal.c:2871
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1129f8eba9
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RSP: 002b:00007f112ad790e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f112a1d5fa8 RCX: 00007f1129f8eba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f112a1d5fa8
RBP: 00007f112a1d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f112a1d6038 R14: 00007ffd4a0e2cb0 R15: 00007ffd4a0e2d98
</TASK>
INFO: task syz.1.87:4661 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.87 state:D stack:25320 pid:4661 ppid:4400 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
schedule+0xb9/0x180 kernel/sched/core.c:6637
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
__mmput+0x118/0x3c0 kernel/fork.c:1200
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_exit+0x8c1/0x2400 kernel/exit.c:867
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
get_signal+0x1272/0x1350 kernel/signal.c:2871
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa93d98eba9
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RSP: 002b:00007fa93e7ce0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fa93dbd5fa8 RCX: 00007fa93d98eba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa93dbd5fa8
RBP: 00007fa93dbd5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa93dbd6038 R14: 00007ffd98d65980 R15: 00007ffd98d65a68
</TASK>
Showing all locks held in the system:
3 locks held by kworker/u4:1/11:
Showing all locks held in the system:
#0: ffff8880b8f3aad8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
#1: ffff8880b8f27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x398/0x6d0 kernel/sched/psi.c:999
#2: ffff8880b8f28418 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:999
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2b370 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2bb90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
#0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by kworker/u4:3/51:
#0: ffff8880b8f3aad8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
#1: ffff8880b8f27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x398/0x6d0 kernel/sched/psi.c:999
2 locks held by udevd/3637:
#0: ffffffff8cbc4c50 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:593 [inline]
#0: ffffffff8cbc4c50 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline]
#0: ffffffff8cbc4c50 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x2a9/0x15c0 kernel/fork.c:1590
#1: ffff88807c1f9058 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff88807c1f9058 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:594 [inline]
#1: ffff88807c1f9058 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1541 [inline]
#1: ffff88807c1f9058 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x2c3/0x15c0 kernel/fork.c:1590
1 lock held by dhcpcd/3932:
#0: ffffffff8cb53610 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: copy_process+0x248b/0x4020 kernel/fork.c:2446
2 locks held by getty/4031:
#0: ffff88802fc87098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/4397:
#0: ffff8880174688d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880174688d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4399:
#0: ffff88801746b5d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88801746b5d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4400:
#0: ffff8880274b9058 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880274b9058 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4407:
#0: ffff8880274b8158 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880274b8158 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4409:
#0: ffff8880769f17d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880769f17d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.4.21/4586:
#0: ffff88807caf62d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88807caf62d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.3.86/4662:
#0: ffff8880273bf958 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880273bf958 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.1.87/4661:
#0: ffff8880273b8158 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880273b8158 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.0.88/4663:
#0: ffff8880273b9f58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880273b9f58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
2 locks held by syz-executor/4665:
#0: ffffffff8cbc4c50 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:593 [inline]
#0: ffffffff8cbc4c50 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline]
#0: ffffffff8cbc4c50 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x2a9/0x15c0 kernel/fork.c:1590
#1: ffff8880273b88d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#1: ffff8880273b88d8 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:594 [inline]
#1: ffff8880273b88d8 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1541 [inline]
#1: ffff8880273b88d8 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x2c3/0x15c0 kernel/fork.c:1590
1 lock held by syz-executor/4680:
#0: ffffffff8cb53610 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: do_exit+0x578/0x2400 kernel/exit.c:827
7 locks held by syz-executor/4707:
#0: ffff8880196b6460 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580
#1: ffff888028204088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e5/0x4c0 fs/kernfs/file.c:325
#2: ffffffff8cb53428 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:442 [inline]
#2: ffffffff8cb53428 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1677
#3: ffffffff8c9c7870 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2453 [inline]
#3: ffffffff8c9c7870 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x183/0x600 kernel/cgroup/cgroup.c:2959
#4: ffffffff8cb53610 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2455 [inline]
#4: ffffffff8cb53610 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x199/0x600 kernel/cgroup/cgroup.c:2959
#5: ffffffff8cb619a8 (cpuset_mutex){+.+.}-{3:3}, at: cpuset_attach+0xac/0x540 kernel/cgroup/cpuset.c:2647
#6: ffff8880273bd3d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#6: ffff8880273bd3d8 (&mm->mmap_lock){++++}-{3:3}, at: mpol_rebind_mm+0xbe/0x370 mm/mempolicy.c:386
3 locks held by syz-executor/4710:
#0: ffff88807a79e460 (sb_writers#10){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:393
#1: ffff88806e009080 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
#1: ffff88806e009080 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: filename_create+0x1f2/0x450 fs/namei.c:3876
#2: ffffffff8cb53428 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:442 [inline]
#2: ffffffff8cb53428 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xee/0x230 kernel/cgroup/cgroup.c:1677
2 locks held by syz-executor/4717:
#0: ffff88807a79e460 (sb_writers#10){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:393
#1: ffff88806e009080 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
#1: ffff88806e009080 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: filename_create+0x1f2/0x450 fs/namei.c:3876
1 lock held by syz.6.148/4864:
#0: ffff88807c1fe2d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88807c1fe2d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
<TASK>
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 1 to CPUs 0:
<TASK>
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 75 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:poke_int3_handler+0x170/0x1d0 arch/x86/kernel/alternative.c:1700
Code: 48 89 87 80 00 00 00 b8 01 00 00 00 f0 ff 0d 13 cd 77 05 c3 81 c6 3d ff ff ff 83 fe 28 77 5b ff 24 f5 40 75 86 8a 48 63 40 04 <eb> d1 31 c0 f0 ff 0d f1 cc 77 05 c3 48 8b 8f 98 00 00 00 48 8b 01
RSP: 0018:ffffc90001577998 EFLAGS: 00000093
RAX: 000000000000022a RBX: ffffc900015779b8 RCX: ffffffff81d0228f
RDX: ffffffff81d0228b RSI: 0000000000000026 RDI: ffffc900015779b8
RBP: 0000000000000000 R08: 0000000000000079 R09: ffffffff8f8edcd0
R10: ffffffff81d0228a R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe3c3073680 CR3: 000000000c88e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
exc_int3+0xa/0x70 arch/x86/kernel/traps.c:827
asm_exc_int3+0x35/0x40 arch/x86/include/asm/idtentry.h:607
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline]
RIP: 0010:kfence_alloc include/linux/kfence.h:120 [inline]
RIP: 0010:slab_alloc_node mm/slub.c:3283 [inline]
RIP: 0010:kmem_cache_alloc_node+0x6b/0x320 mm/slub.c:3404
Code: 00 00 00 31 db 48 8d 54 24 10 b9 01 00 00 00 31 f6 45 89 f0 e8 46 13 00 00 48 85 c0 0f 84 ef 00 00 00 49 89 c5 4c 89 24 24 cc <1f> 44 00 00 49 8b 45 00 65 48 03 05 0d f7 31 7e 48 8b 50 08 4c 8b
RSP: 0018:ffffc90001577a98 EFLAGS: 00000286
RAX: ffff8881401e5500 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 00000000000000f0 RDI: ffffffff8cc1cdc0
RBP: 00000000ffffffff R08: 0000000000000a20 R09: fffffbfff215c468
R10: fffffbfff215c468 R11: 1ffffffff215c467 R12: 00000000000000f0
R13: ffff8881401e5500 R14: 0000000000000a20 R15: ffff8881401e5500
__alloc_skb+0xfc/0x7e0 net/core/skbuff.c:505
alloc_skb include/linux/skbuff.h:1271 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x28f/0xaf0 drivers/net/netdevsim/dev.c:851
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
---
If you want syzbot to run the reproducer, reply with:
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
---
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
syzbot
Sep 26, 2025, 11:11:37 AM9/26/25
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:
HEAD commit: 7b34dc04e4ff Linux 6.1.154
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=152f7ce2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7eb38bd5021fec61
dashboard link: https://syzkaller.appspot.com/bug?extid=4ae44039c268079df003
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132f7ce2580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/cb7cb7b3a100/disk-7b34dc04.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e06d58b4fc92/vmlinux-7b34dc04.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ed0693e83723/bzImage-7b34dc04.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4ae440...@syzkaller.appspotmail.com
INFO: task syz.2.26:4532 blocked for more than 143 seconds.
Not tainted syzkaller #0
__se_sys_exit_group kernel/exit.c:1031 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031
RSP: 002b:00007ffc04874398 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9fc738eec9
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000002
R13: 00000000000927c0 R14: 000000000002967d R15: 00007ffc04874450
</TASK>
INFO: task syz.0.27:4533 blocked for more than 143 seconds.
Not tainted syzkaller #0
__se_sys_exit_group kernel/exit.c:1031 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031
RSP: 002b:00007ffc23793c18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff13198eec9
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000004
R13: 00000000000927c0 R14: 00000000000296a2 R15: 00007ffc23793cd0
</TASK>
INFO: task syz.4.45:4556 blocked for more than 144 seconds.
Not tainted syzkaller #0
__se_sys_exit_group kernel/exit.c:1031 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031
RSP: 002b:00007ffd35a85488 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007faf2658eec9
R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000000e
R13: 00000000000927c0 R14: 0000000000029eb0 R15: 00007ffd35a85540
#0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900000e7d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by getty/4029:
#0: ffff88814cf09098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/4293:
#0: ffff888028b871d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#0: ffff888028b871d8 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15d/0x2b0 mm/util.c:518
1 lock held by syz-executor/4400:
#0: ffff888017469058 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888017469058 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4402:
#0: ffff88802f5262d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88802f5262d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
#0: ffff88802f523d58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4408:
#0: ffff88802f5235d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88802f5235d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4413:
#0: ffff88802f5253d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88802f5253d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.2.26/4532:
#0: ffff888018685b58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888018685b58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.0.27/4533:
#0: ffff888018683d58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888018683d58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.4.45/4556:
#0: ffff888073251f58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888073251f58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4898:
#0: ffff88807cd2ea58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88807cd2ea58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4906:
#0: ffff88807cd2f958 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88807cd2f958 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
3 locks held by kworker/u4:9/5060:
1 lock held by modprobe/5103:
#0: ffff888028b844d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888028b844d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.3.494/5104:
#0: ffff888028b835d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888028b835d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.6.500/5112:
#0: ffff8880776388d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880776388d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by udevd/5120:
#0: ffff88807763cc58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#0: ffff88807763cc58 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0x141/0x290 mm/mmap.c:2933
1 lock held by syz-executor/5133:
#0: ffff888073256a58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888073256a58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.1.531/5221:
#0: ffff88807cd29f58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88807cd29f58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.9.532/5222:
#0: ffff88807cd2a6d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88807cd2a6d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.2.533/5223:
#0: ffff888018684c58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888018684c58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:unwind_next_frame+0x6dd/0x20b0 arch/x86/kernel/unwind_orc.c:471
Code: 00 00 44 89 f9 80 e1 07 38 c1 0f 8c 75 02 00 00 be 02 00 00 00 49 89 d6 4c 89 ff e8 ad 85 98 00 e9 3b 18 00 00 48 8b 44 24 50 <42> 80 3c 28 00 4c 8b 74 24 58 74 08 4c 89 f7 e8 cf 84 98 00 49 8b
RSP: 0018:ffffc900045e7310 EFLAGS: 00000297
RAX: 1ffff920008bce84 RBX: ffffc900045e73e8 RCX: ffffffff8e7f3a04
RDX: ffffffff8f1708e6 RSI: ffffffff8e7f3a00 RDI: 0000000000000001
RBP: ffffffff8f1708ea R08: 0000000000000001 R09: 0000000000000008
R10: fffff520008bce89 R11: 1ffff920008bce87 R12: ffffffff8f1708e6
R13: dffffc0000000000 R14: ffffffff8e7f3a00 R15: 0000000000000005
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
save_stack+0xf3/0x1e0 mm/page_owner.c:127
__set_page_owner+0x19/0x60 mm/page_owner.c:190
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532
prep_new_page mm/page_alloc.c:2539 [inline]
get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328
__alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614
alloc_slab_page+0x5d/0x160 mm/slub.c:1799
allocate_slab mm/slub.c:1944 [inline]
new_slab+0x87/0x2c0 mm/slub.c:1997
___slab_alloc+0xbc6/0x1230 mm/slub.c:3154
__slab_alloc mm/slub.c:3240 [inline]
slab_alloc_node mm/slub.c:3325 [inline]
__kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398
__do_kmalloc_node mm/slab_common.c:935 [inline]
__kmalloc_node_track_caller+0x9e/0x230 mm/slab_common.c:956
kmalloc_reserve net/core/skbuff.c:446 [inline]
__alloc_skb+0x22a/0x7e0 net/core/skbuff.c:515
HEAD commit: 7b34dc04e4ff Linux 6.1.154
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=152f7ce2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7eb38bd5021fec61
dashboard link: https://syzkaller.appspot.com/bug?extid=4ae44039c268079df003
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=159d3ce2580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=132f7ce2580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/cb7cb7b3a100/disk-7b34dc04.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e06d58b4fc92/vmlinux-7b34dc04.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ed0693e83723/bzImage-7b34dc04.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4ae440...@syzkaller.appspotmail.com
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.26 state:D stack:25192 pid:4532 ppid:4407 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
schedule+0xb9/0x180 kernel/sched/core.c:6637
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
__mmput+0x118/0x3c0 kernel/fork.c:1200
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_exit+0x8c1/0x2400 kernel/exit.c:867
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
__do_sys_exit_group kernel/exit.c:1033 [inline]
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
__se_sys_exit_group kernel/exit.c:1031 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9fc738eec9
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RSP: 002b:00007ffc04874398 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9fc738eec9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc048743fc R08: 000000050487448f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000002
R13: 00000000000927c0 R14: 000000000002967d R15: 00007ffc04874450
</TASK>
INFO: task syz.0.27:4533 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.27 state:D stack:25032 pid:4533 ppid:4400 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
schedule+0xb9/0x180 kernel/sched/core.c:6637
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
__mmput+0x118/0x3c0 kernel/fork.c:1200
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_exit+0x8c1/0x2400 kernel/exit.c:867
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
__do_sys_exit_group kernel/exit.c:1033 [inline]
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
__se_sys_exit_group kernel/exit.c:1031 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff13198eec9
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RSP: 002b:00007ffc23793c18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff13198eec9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc23793c7c R08: 0000000523793d0f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000004
R13: 00000000000927c0 R14: 00000000000296a2 R15: 00007ffc23793cd0
</TASK>
INFO: task syz.4.45:4556 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.45 state:D stack:25696 pid:4556 ppid:4413 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
schedule+0xb9/0x180 kernel/sched/core.c:6637
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
rwsem_down_write_slowpath+0xbed/0x1090 kernel/locking/rwsem.c:1189
mmap_write_lock include/linux/mmap_lock.h:71 [inline]
__mmput+0x118/0x3c0 kernel/fork.c:1200
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
exit_mm+0x1e6/0x2c0 kernel/exit.c:565
do_exit+0x8c1/0x2400 kernel/exit.c:867
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
__do_sys_exit_group kernel/exit.c:1033 [inline]
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
__se_sys_exit_group kernel/exit.c:1031 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7faf2658eec9
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RSP: 002b:00007ffd35a85488 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007faf2658eec9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd35a854ec R08: 0000000535a8557f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000000e
R13: 00000000000927c0 R14: 0000000000029eb0 R15: 00007ffd35a85540
</TASK>
Showing all locks held in the system:
2 locks held by kworker/u4:0/9:
Showing all locks held in the system:
#0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900000e7d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2b570 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2bd90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by getty/4029:
#0: ffff88814cf09098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/4293:
#0: ffff888028b871d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#0: ffff888028b871d8 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15d/0x2b0 mm/util.c:518
1 lock held by syz-executor/4400:
#0: ffff888017469058 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888017469058 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4402:
#0: ffff88802f5262d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88802f5262d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4407:
#0: ffff88802f523d58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88802f523d58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4408:
#0: ffff88802f5235d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88802f5235d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4413:
#0: ffff88802f5253d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88802f5253d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.2.26/4532:
#0: ffff888018685b58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888018685b58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.0.27/4533:
#0: ffff888018683d58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888018683d58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.4.45/4556:
#0: ffff888073251f58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888073251f58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4898:
#0: ffff88807cd2ea58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88807cd2ea58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz-executor/4906:
#0: ffff88807cd2f958 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88807cd2f958 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
3 locks held by kworker/u4:9/5060:
1 lock held by modprobe/5103:
#0: ffff888028b844d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888028b844d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.3.494/5104:
#0: ffff888028b835d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888028b835d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.6.500/5112:
#0: ffff8880776388d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff8880776388d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by udevd/5120:
#0: ffff88807763cc58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
#0: ffff88807763cc58 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0x141/0x290 mm/mmap.c:2933
1 lock held by syz-executor/5133:
#0: ffff888073256a58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888073256a58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.1.531/5221:
#0: ffff88807cd29f58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88807cd29f58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.9.532/5222:
#0: ffff88807cd2a6d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff88807cd2a6d8 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
1 lock held by syz.2.533/5223:
#0: ffff888018684c58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:71 [inline]
#0: ffff888018684c58 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x20f/0x8e0 mm/mmap.c:3258
=============================================
NMI backtrace for cpu 0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
<TASK>
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4392 Comm: kworker/u4:5 Not tainted syzkaller #0
<TASK>
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:unwind_next_frame+0x6dd/0x20b0 arch/x86/kernel/unwind_orc.c:471
Code: 00 00 44 89 f9 80 e1 07 38 c1 0f 8c 75 02 00 00 be 02 00 00 00 49 89 d6 4c 89 ff e8 ad 85 98 00 e9 3b 18 00 00 48 8b 44 24 50 <42> 80 3c 28 00 4c 8b 74 24 58 74 08 4c 89 f7 e8 cf 84 98 00 49 8b
RSP: 0018:ffffc900045e7310 EFLAGS: 00000297
RAX: 1ffff920008bce84 RBX: ffffc900045e73e8 RCX: ffffffff8e7f3a04
RDX: ffffffff8f1708e6 RSI: ffffffff8e7f3a00 RDI: 0000000000000001
RBP: ffffffff8f1708ea R08: 0000000000000001 R09: 0000000000000008
R10: fffff520008bce89 R11: 1ffff920008bce87 R12: ffffffff8f1708e6
R13: dffffc0000000000 R14: ffffffff8e7f3a00 R15: 0000000000000005
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055743117f660 CR3: 000000002eabb000 CR4: 00000000003506e0
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
save_stack+0xf3/0x1e0 mm/page_owner.c:127
__set_page_owner+0x19/0x60 mm/page_owner.c:190
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532
prep_new_page mm/page_alloc.c:2539 [inline]
get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328
__alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614
alloc_slab_page+0x5d/0x160 mm/slub.c:1799
allocate_slab mm/slub.c:1944 [inline]
new_slab+0x87/0x2c0 mm/slub.c:1997
___slab_alloc+0xbc6/0x1230 mm/slub.c:3154
__slab_alloc mm/slub.c:3240 [inline]
slab_alloc_node mm/slub.c:3325 [inline]
__kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398
__do_kmalloc_node mm/slab_common.c:935 [inline]
__kmalloc_node_track_caller+0x9e/0x230 mm/slab_common.c:956
kmalloc_reserve net/core/skbuff.c:446 [inline]
__alloc_skb+0x22a/0x7e0 net/core/skbuff.c:515
alloc_skb include/linux/skbuff.h:1271 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x28f/0xaf0 drivers/net/netdevsim/dev.c:851
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x28f/0xaf0 drivers/net/netdevsim/dev.c:851
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
---
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
---
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