[v6.6] INFO: task hung in exit_mmap
0 views
Skip to first unread message
syzbot
Sep 26, 2025, 4:35:32 AM (13 days ago) Sep 26
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 147338df3487 Linux 6.6.108
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16f742e2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=12606d4b8832c7e4
dashboard link: https://syzkaller.appspot.com/bug?extid=29425e599d1d7f33029b
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=17515d34580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=169e9142580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/535c4ea595d6/disk-147338df.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2d6c4ceaffc3/vmlinux-147338df.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0ed56233e74e/bzImage-147338df.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+29425e...@syzkaller.appspotmail.com
INFO: task syz.3.20:6034 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.20 state:D stack:24496 pid:6034 ppid:5932 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
mmap_write_lock include/linux/mmap_lock.h:108 [inline]
exit_mmap+0x245/0xb50 mm/mmap.c:3310
__mmput+0x118/0x3c0 kernel/fork.c:1355
exit_mm+0x1da/0x2c0 kernel/exit.c:569
do_exit+0x88e/0x23c0 kernel/exit.c:870
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc97eb8eec9
RSP: 002b:00007ffebf4011a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc97eb8eec9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 00000005bf40129f R09: 00007fc97edb1280
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc97edb1280 R14: 0000000000000003 R15: 00007ffebf401260
</TASK>
INFO: task syz.2.53:6035 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.53 state:D stack:24904 pid:6035 ppid:5929 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
mmap_write_lock include/linux/mmap_lock.h:108 [inline]
exit_mmap+0x245/0xb50 mm/mmap.c:3310
__mmput+0x118/0x3c0 kernel/fork.c:1355
exit_mm+0x1da/0x2c0 kernel/exit.c:569
do_exit+0x88e/0x23c0 kernel/exit.c:870
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f82dfb8eec9
RSP: 002b:00007ffcc46c8368 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f82dfb8eec9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffcc46c83cc R08: 00000005c46c845f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000001e
R13: 00000000000927c0 R14: 0000000000026feb R15: 00007ffcc46c8420
</TASK>
INFO: task syz.1.18:6036 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.18 state:D stack:24208 pid:6036 ppid:5927 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
mmap_write_lock include/linux/mmap_lock.h:108 [inline]
exit_mmap+0x245/0xb50 mm/mmap.c:3310
__mmput+0x118/0x3c0 kernel/fork.c:1355
exit_mm+0x1da/0x2c0 kernel/exit.c:569
do_exit+0x88e/0x23c0 kernel/exit.c:870
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f33d8b8eec9
RSP: 002b:00007ffc471c6d38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f33d8b8eec9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 00000005471c6e2f R09: 00007f33d8db1280
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f33d8db1280 R14: 0000000000000003 R15: 00007ffc471c6df0
</TASK>
INFO: task syz.0.54:6037 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.54 state:D stack:24656 pid:6037 ppid:5924 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
mmap_write_lock include/linux/mmap_lock.h:108 [inline]
exit_mmap+0x245/0xb50 mm/mmap.c:3310
__mmput+0x118/0x3c0 kernel/fork.c:1355
exit_mm+0x1da/0x2c0 kernel/exit.c:569
do_exit+0x88e/0x23c0 kernel/exit.c:870
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1d2d78eec9
RSP: 002b:00007ffc56d2e808 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1d2d78eec9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc56d2e86c R08: 0000000556d2e8ff R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000004
R13: 00000000000927c0 R14: 0000000000027034 R15: 00007ffc56d2e8c0
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:3/48:
4 locks held by kworker/u4:8/1113:
1 lock held by syslogd/5141:
#0: ffff8880b8f3c218 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558
2 locks held by udevd/5159:
#0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:657 [inline]
#0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1692 [inline]
#0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x266/0x1c20 kernel/fork.c:1741
#1: ffff88806b4f14a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
#1: ffff88806b4f14a0 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:658 [inline]
#1: ffff88806b4f14a0 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1692 [inline]
#1: ffff88806b4f14a0 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x281/0x1c20 kernel/fork.c:1741
2 locks held by getty/5554:
#0: ffff88803108a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000328b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by syz-executor/5818:
#0: ffff88807dca14a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
#0: ffff88807dca14a0 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x168/0x400 mm/util.c:554
1 lock held by udevd/5831:
#0: ffff88806a5ab120 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
#0: ffff88806a5ab120 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0x14a/0x3c0 mm/mmap.c:2958
1 lock held by syz-executor/5924:
#0: ffff88803107c420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88803107c420 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz-executor/5927:
#0: ffff88803107baa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88803107baa0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz-executor/5929:
#0: ffff88802c36c420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88802c36c420 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz-executor/5932:
#0: ffff88802c36e0a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88802c36e0a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.3.20/6034:
#0: ffff88803107d720 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88803107d720 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.2.53/6035:
#0: ffff88807af84420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88807af84420 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.1.18/6036:
#0: ffff88803107cda0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88803107cda0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.0.54/6037:
#0: ffff88807af83aa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88807af83aa0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz-executor/6041:
#0: ffff88807af827a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88807af827a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
2 locks held by syz-executor/6051:
#0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:657 [inline]
#0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1692 [inline]
#0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x266/0x1c20 kernel/fork.c:1741
#1: ffff88803107b120 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
#1: ffff88803107b120 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:658 [inline]
#1: ffff88803107b120 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1692 [inline]
#1: ffff88803107b120 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x281/0x1c20 kernel/fork.c:1741
1 lock held by syz.5.56/6150:
#0: ffff88802f58baa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88802f58baa0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.6.57/6151:
#0: ffff88802f58d720 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88802f58d720 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 48 Comm: kworker/u4:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:get_random_bytes+0x0/0x20 drivers/char/random.c:415
Code: e6 fc eb a7 e8 61 b8 e6 fc eb a0 e8 5a b8 e6 fc eb 99 e8 53 b8 e6 fc 44 89 f8 c1 f8 1f 44 21 f8 eb 8b 0f 1f 84 00 00 00 00 00 <f3> 0f 1e fa 41 56 53 48 89 f3 49 89 fe e8 2e b8 e6 fc 4c 89 f7 48
RSP: 0018:ffffc90000b97ac8 EFLAGS: 00000282
RAX: ffff888044a30000 RBX: 0000000000000000 RCX: ffff88801de5da00
RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffff888044a30000
RBP: ffff888144364dd8 R08: ffff888044a30ee3 R09: 1ffff110089461dc
R10: dffffc0000000000 R11: ffffed10089461dd R12: dffffc0000000000
R13: ffff888031cb7140 R14: ffff888044a30000 R15: 0000000000000080
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556a4b8a8660 CR3: 000000002ec83000 CR4: 00000000003506f0
Call Trace:
<TASK>
eth_random_addr include/linux/etherdevice.h:232 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:755 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x338/0xb00 drivers/net/netdevsim/dev.c:851
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</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 syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
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 found the following issue on:
HEAD commit: 147338df3487 Linux 6.6.108
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16f742e2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=12606d4b8832c7e4
dashboard link: https://syzkaller.appspot.com/bug?extid=29425e599d1d7f33029b
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=17515d34580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=169e9142580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/535c4ea595d6/disk-147338df.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2d6c4ceaffc3/vmlinux-147338df.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0ed56233e74e/bzImage-147338df.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+29425e...@syzkaller.appspotmail.com
INFO: task syz.3.20:6034 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.20 state:D stack:24496 pid:6034 ppid:5932 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
mmap_write_lock include/linux/mmap_lock.h:108 [inline]
exit_mmap+0x245/0xb50 mm/mmap.c:3310
__mmput+0x118/0x3c0 kernel/fork.c:1355
exit_mm+0x1da/0x2c0 kernel/exit.c:569
do_exit+0x88e/0x23c0 kernel/exit.c:870
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc97eb8eec9
RSP: 002b:00007ffebf4011a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc97eb8eec9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 00000005bf40129f R09: 00007fc97edb1280
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc97edb1280 R14: 0000000000000003 R15: 00007ffebf401260
</TASK>
INFO: task syz.2.53:6035 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.53 state:D stack:24904 pid:6035 ppid:5929 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
mmap_write_lock include/linux/mmap_lock.h:108 [inline]
exit_mmap+0x245/0xb50 mm/mmap.c:3310
__mmput+0x118/0x3c0 kernel/fork.c:1355
exit_mm+0x1da/0x2c0 kernel/exit.c:569
do_exit+0x88e/0x23c0 kernel/exit.c:870
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f82dfb8eec9
RSP: 002b:00007ffcc46c8368 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f82dfb8eec9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffcc46c83cc R08: 00000005c46c845f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000001e
R13: 00000000000927c0 R14: 0000000000026feb R15: 00007ffcc46c8420
</TASK>
INFO: task syz.1.18:6036 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.18 state:D stack:24208 pid:6036 ppid:5927 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
mmap_write_lock include/linux/mmap_lock.h:108 [inline]
exit_mmap+0x245/0xb50 mm/mmap.c:3310
__mmput+0x118/0x3c0 kernel/fork.c:1355
exit_mm+0x1da/0x2c0 kernel/exit.c:569
do_exit+0x88e/0x23c0 kernel/exit.c:870
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f33d8b8eec9
RSP: 002b:00007ffc471c6d38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f33d8b8eec9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 00000005471c6e2f R09: 00007f33d8db1280
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f33d8db1280 R14: 0000000000000003 R15: 00007ffc471c6df0
</TASK>
INFO: task syz.0.54:6037 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.54 state:D stack:24656 pid:6037 ppid:5924 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
mmap_write_lock include/linux/mmap_lock.h:108 [inline]
exit_mmap+0x245/0xb50 mm/mmap.c:3310
__mmput+0x118/0x3c0 kernel/fork.c:1355
exit_mm+0x1da/0x2c0 kernel/exit.c:569
do_exit+0x88e/0x23c0 kernel/exit.c:870
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1d2d78eec9
RSP: 002b:00007ffc56d2e808 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1d2d78eec9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc56d2e86c R08: 0000000556d2e8ff R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000004
R13: 00000000000927c0 R14: 0000000000027034 R15: 00007ffc56d2e8c0
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
3 locks held by kworker/u4:3/48:
4 locks held by kworker/u4:8/1113:
1 lock held by syslogd/5141:
#0: ffff8880b8f3c218 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558
2 locks held by udevd/5159:
#0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:657 [inline]
#0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1692 [inline]
#0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x266/0x1c20 kernel/fork.c:1741
#1: ffff88806b4f14a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
#1: ffff88806b4f14a0 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:658 [inline]
#1: ffff88806b4f14a0 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1692 [inline]
#1: ffff88806b4f14a0 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x281/0x1c20 kernel/fork.c:1741
2 locks held by getty/5554:
#0: ffff88803108a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000328b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by syz-executor/5818:
#0: ffff88807dca14a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
#0: ffff88807dca14a0 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x168/0x400 mm/util.c:554
1 lock held by udevd/5831:
#0: ffff88806a5ab120 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
#0: ffff88806a5ab120 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0x14a/0x3c0 mm/mmap.c:2958
1 lock held by syz-executor/5924:
#0: ffff88803107c420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88803107c420 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz-executor/5927:
#0: ffff88803107baa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88803107baa0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz-executor/5929:
#0: ffff88802c36c420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88802c36c420 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz-executor/5932:
#0: ffff88802c36e0a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88802c36e0a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.3.20/6034:
#0: ffff88803107d720 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88803107d720 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.2.53/6035:
#0: ffff88807af84420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88807af84420 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.1.18/6036:
#0: ffff88803107cda0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88803107cda0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.0.54/6037:
#0: ffff88807af83aa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88807af83aa0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz-executor/6041:
#0: ffff88807af827a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88807af827a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
2 locks held by syz-executor/6051:
#0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:657 [inline]
#0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1692 [inline]
#0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x266/0x1c20 kernel/fork.c:1741
#1: ffff88803107b120 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
#1: ffff88803107b120 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:658 [inline]
#1: ffff88803107b120 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1692 [inline]
#1: ffff88803107b120 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x281/0x1c20 kernel/fork.c:1741
1 lock held by syz.5.56/6150:
#0: ffff88802f58baa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88802f58baa0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.6.57/6151:
#0: ffff88802f58d720 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88802f58d720 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 48 Comm: kworker/u4:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:get_random_bytes+0x0/0x20 drivers/char/random.c:415
Code: e6 fc eb a7 e8 61 b8 e6 fc eb a0 e8 5a b8 e6 fc eb 99 e8 53 b8 e6 fc 44 89 f8 c1 f8 1f 44 21 f8 eb 8b 0f 1f 84 00 00 00 00 00 <f3> 0f 1e fa 41 56 53 48 89 f3 49 89 fe e8 2e b8 e6 fc 4c 89 f7 48
RSP: 0018:ffffc90000b97ac8 EFLAGS: 00000282
RAX: ffff888044a30000 RBX: 0000000000000000 RCX: ffff88801de5da00
RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffff888044a30000
RBP: ffff888144364dd8 R08: ffff888044a30ee3 R09: 1ffff110089461dc
R10: dffffc0000000000 R11: ffffed10089461dd R12: dffffc0000000000
R13: ffff888031cb7140 R14: ffff888044a30000 R15: 0000000000000080
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556a4b8a8660 CR3: 000000002ec83000 CR4: 00000000003506f0
Call Trace:
<TASK>
eth_random_addr include/linux/etherdevice.h:232 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:755 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x338/0xb00 drivers/net/netdevsim/dev.c:851
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</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 syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
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
Reply all
Reply to author
Forward
0 new messages