[syzbot] [kasan?] [mm?] INFO: task hung in hugetlb_wp

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 6b0f8db921ab Merge tag 'execve-v6.11-rc4' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16509e8d980000
kernel config: https://syzkaller.appspot.com/x/.config?x=801d05d1ea4be1b8
dashboard link: https://syzkaller.appspot.com/bug?extid=c391aebb8e8e8cd95c55
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8e1d5e5016fb/disk-6b0f8db9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0487df01ffef/vmlinux-6b0f8db9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/cc8e8e0932d5/bzImage-6b0f8db9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c391ae...@syzkaller.appspotmail.com

INFO: task syz.3.186:6037 blocked for more than 143 seconds.
Not tainted 6.11.0-rc3-syzkaller-00013-g6b0f8db921ab #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.186 state:D stack:25688 pid:6037 tgid:6037 ppid:5773 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5188 [inline]
__schedule+0x1800/0x4a60 kernel/sched/core.c:6529
__schedule_loop kernel/sched/core.c:6606 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6621
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678
__mutex_lock_common kernel/locking/mutex.c:684 [inline]
__mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
hugetlb_wp+0x104d/0x3a90 mm/hugetlb.c:6027
hugetlb_fault+0x26de/0x3780 mm/hugetlb.c:6579
handle_mm_fault+0x173f/0x1980 mm/memory.c:5831
do_user_addr_fault arch/x86/mm/fault.c:1338 [inline]
handle_page_fault arch/x86/mm/fault.c:1481 [inline]
exc_page_fault+0x459/0x8c0 arch/x86/mm/fault.c:1539
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f31cf341498
RSP: 002b:00007f31cf63fb98 EFLAGS: 00010246
RAX: 0000000020000080 RBX: 0000000000000004 RCX: 0070616d65676170
RDX: 0000000000000008 RSI: 0070616d65676170 RDI: 0000000020000080
RBP: 00007f31cf63fc70 R08: 00007f31cf200000 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000009 R12: 0000000000000032
R13: 00007f31cf63fc90 R14: 00007f31cf63fcb0 R15: fffffffffffffffe
</TASK>
INFO: task syz.3.186:6038 blocked for more than 143 seconds.
Not tainted 6.11.0-rc3-syzkaller-00013-g6b0f8db921ab #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.186 state:D stack:22360 pid:6038 tgid:6037 ppid:5773 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5188 [inline]
__schedule+0x1800/0x4a60 kernel/sched/core.c:6529
__schedule_loop kernel/sched/core.c:6606 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6621
io_schedule+0x8d/0x110 kernel/sched/core.c:7401
folio_wait_bit_common+0x882/0x12b0 mm/filemap.c:1307
__filemap_get_folio+0xb7/0xc10 mm/filemap.c:1898
hugetlb_fault+0x1b10/0x3780 mm/hugetlb.c:6531
handle_mm_fault+0x173f/0x1980 mm/memory.c:5831
do_user_addr_fault arch/x86/mm/fault.c:1389 [inline]
handle_page_fault arch/x86/mm/fault.c:1481 [inline]
exc_page_fault+0x2b9/0x8c0 arch/x86/mm/fault.c:1539
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:__put_user_8+0x11/0x20 arch/x86/lib/putuser.S:107
Code: 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 89 cb 48 c1 fb 3f 48 09 d9 0f 01 cb <48> 89 01 31 c9 0f 01 ca c3 cc cc cc cc 66 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000317f778 EFLAGS: 00050202
RAX: 0000000000800000 RBX: 0000000000000000 RCX: 0000000020000020
RDX: 0000000000000000 RSI: ffffffff8c0ae6e0 RDI: ffffffff8c606400
RBP: ffffc9000317fec8 R08: ffffffff9017ce2f R09: 1ffffffff202f9c5
R10: dffffc0000000000 R11: fffffbfff202f9c6 R12: 1ffff9200062ff7d
R13: 1ffff9200062ff08 R14: 0000000020800000 R15: 0000000000800000
userfaultfd_copy fs/userfaultfd.c:1735 [inline]
userfaultfd_ioctl+0x28e7/0x70a0 fs/userfaultfd.c:2133
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f31cf3799f9
RSP: 002b:00007f31d00e5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f31cf515f80 RCX: 00007f31cf3799f9
RDX: 0000000020000000 RSI: 00000000c028aa03 RDI: 0000000000000004
RBP: 00007f31cf3e78ee R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f31cf515f80 R15: 00007f31cf63fa38
</TASK>

Showing all locks held in the system:
3 locks held by kworker/1:0/25:
1 lock held by khungtaskd/30:
#0: ffffffff8e9382e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
#0: ffffffff8e9382e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e9382e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6626
3 locks held by kworker/u8:2/35:
3 locks held by kworker/1:1/46:
#0: ffff888015880948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
#0: ffff888015880948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
#1: ffffc90000b67d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
#1: ffffc90000b67d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
#2: ffff888062701240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2d1/0x4130 drivers/net/netdevsim/fib.c:1489
3 locks held by kworker/u8:3/52:
#0: ffff888015889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
#0: ffff888015889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
#1: ffffc90000bc7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
#1: ffffc90000bc7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
#2: ffffffff8fc82308 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
4 locks held by kworker/u8:10/2503:
#0: ffff8880166e5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
#0: ffff8880166e5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
#1: ffffc90008c67d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
#1: ffffc90008c67d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
#2: ffffffff8fc75790 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:594
#3: ffffffff8fc82308 (rtnl_mutex){+.+.}-{3:3}, at: fib_net_exit_batch+0x20/0x90 net/ipv4/fib_frontend.c:1638
1 lock held by dhcpcd/4896:
#0: ffffffff8fc82308 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2ce/0x1bc0 net/ipv4/devinet.c:1101
2 locks held by getty/4983:
#0: ffff88802af030a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ac/0x1e00 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5218:
3 locks held by kworker/0:4/5282:
#0: ffff888015880948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
#0: ffff888015880948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
#1: ffffc90004017d00 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
#1: ffffc90004017d00 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
#2: ffffffff8e93d580 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4486
2 locks held by syz.3.186/6037:
#0: ffff888063f3fd18 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:690 [inline]
#0: ffff888063f3fd18 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x2f9/0x6e0 mm/memory.c:5999
#1: ffff88801baea0f8 (&hugetlb_fault_mutex_table[i]){+.+.}-{3:3}, at: hugetlb_wp+0x104d/0x3a90 mm/hugetlb.c:6027
3 locks held by syz.3.186/6038:
#0: ffff88805a331e18 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline]
#0: ffff88805a331e18 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5870 [inline]
#0: ffff88805a331e18 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5930
#1: ffff88801baea0f8 (&hugetlb_fault_mutex_table[i]){+.+.}-{3:3}, at: hugetlb_fault+0x575/0x3780 mm/hugetlb.c:6451
#2: ffff888028c88ce8 (&resv_map->rw_sema){.+.+}-{3:3}, at: hugetlb_fault+0x67b/0x3780 mm/hugetlb.c:6458
2 locks held by syz.3.425/7080:
#0: ffff88801cf73b68 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:690 [inline]
#0: ffff88801cf73b68 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x2f9/0x6e0 mm/memory.c:5999
#1: ffff88801baea0f8 (&hugetlb_fault_mutex_table[i]){+.+.}-{3:3}, at: hugetlb_fault+0x575/0x3780 mm/hugetlb.c:6451
2 locks held by syz-executor/7564:
#0: ffffffff8fc82308 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8fc82308 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3e/0x1b0 drivers/net/tun.c:3510
#1: ffffffff8e93d6b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:296 [inline]
#1: ffffffff8e93d6b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:958
1 lock held by syz-executor/8404:
#0: ffffffff8fc82308 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#0: ffffffff8fc82308 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6644
1 lock held by syz.2.726/8553:
#0: ffffffff8fc82308 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x639/0x1340 net/core/dev_ioctl.c:737

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc3-syzkaller-00013-g6b0f8db921ab #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:379
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 46 Comm: kworker/1:1 Not tainted 6.11.0-rc3-syzkaller-00013-g6b0f8db921ab #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:215
Code: 8b 3d 7c db 95 0c 48 89 de 5b e9 03 94 5b 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 40 d7 03 00 65 8b 15 a0 5f 70 7e 81 e2 00 01 ff 00
RSP: 0018:ffffc90000b67498 EFLAGS: 00000202
RAX: ffffffff81413211 RBX: ffffffff909bed9c RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffc90000b67670
RBP: ffffc90000b675e0 R08: ffffffff8141454b R09: ffffffff814130bf
R10: 0000000000000003 R11: ffff88801becbc00 R12: ffffc90000b67678
R13: dffffc0000000000 R14: ffffc90000b67630 R15: 1ffff9200016cebc
FS: 0000000000000000(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2a2c5c CR3: 0000000022eec000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<TASK>
unwind_next_frame+0x1ac1/0x2a00 arch/x86/kernel/unwind_orc.c:648
__unwind_start+0x641/0x7c0 arch/x86/kernel/unwind_orc.c:760
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x103/0x1b0 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
__kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2252 [inline]
slab_free mm/slub.c:4473 [inline]
kfree+0x149/0x360 mm/slub.c:4594
skb_kfree_head net/core/skbuff.c:1084 [inline]
skb_free_head net/core/skbuff.c:1096 [inline]
skb_release_data+0x676/0x880 net/core/skbuff.c:1123
skb_release_all net/core/skbuff.c:1188 [inline]
__kfree_skb net/core/skbuff.c:1202 [inline]
consume_skb+0xb1/0x160 net/core/skbuff.c:1426
nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
nsim_dev_trap_report_work+0x765/0xaa0 drivers/net/netdevsim/dev.c:850
process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
vkms_vblank_simulate: vblank timer overrun


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