INFO: task syz.0.17:6362 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17 state:D stack:26664 pid:6362 tgid:6359 ppid:6272 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14b8/0x4f90 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x161/0x360 kernel/sched/core.c:6960
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:7017
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x6f2/0x1470 kernel/locking/mutex.c:776
sync_bdevs+0x27a/0x470 block/bdev.c:1305
ksys_sync+0xb5/0x150 fs/sync.c:105
__ia32_sys_sync+0xa/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x86/0x12e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f7df798f749
RSP: 002b:00007f7df87a0038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f7df7be6090 RCX: 00007f7df798f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f7df7be6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7df7be6128 R14: 00007f7df7be6090 R15: 00007ffcb2def438
INFO: task syz.0.17:6362 is blocked on a mutex likely owned by task udevd:6143.
task:udevd state:D stack:21864 pid:6143 tgid:6143 ppid:5173 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14b8/0x4f90 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x161/0x360 kernel/sched/core.c:6960
io_schedule+0x7d/0xd0 kernel/sched/core.c:7789
folio_wait_bit_common+0x7a5/0xb70 mm/filemap.c:1323
folio_wait_bit_killable mm/filemap.c:1468 [inline]
folio_wait_locked_killable include/linux/pagemap.h:1241 [inline]
filemap_read_folio+0x1ff/0x370 mm/filemap.c:2502
do_read_cache_folio+0x358/0x590 mm/filemap.c:4096
read_mapping_folio include/linux/pagemap.h:1017 [inline]
read_part_sector+0xb2/0x2a0 block/partitions/core.c:722
adfspart_check_ICS+0xa0/0xa50 block/partitions/acorn.c:360
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x759/0x14a0 block/partitions/core.c:693
blkdev_get_whole+0x380/0x510 block/bdev.c:765
bdev_open+0x31a/0xd30 block/bdev.c:974
blkdev_open+0x453/0x5f0 block/fops.c:698
do_dentry_open+0x7cc/0x1420 fs/open.c:962
vfs_open+0x37/0x340 fs/open.c:1094
do_open fs/namei.c:4628 [inline]
path_openat+0x3406/0x3dc0 fs/namei.c:4787
do_filp_open+0x1f6/0x400 fs/namei.c:4814
do_sys_openat2+0x11d/0x200 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x134/0x160 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x86/0x12e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f6c6d3e0407
RSP: 002b:00007ffd051649b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f6c6d354880 RCX: 00007f6c6d3e0407
RDX: 00000000000a0800 RSI: 0000559d033d1170 RDI: ffffffffffffff9c
RBP: 0000559d033bf910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000559d033dcf10
R13: 0000559d033cd190 R14: 0000000000000000 R15: 0000559d033dcf10
INFO: task syz.1.18:6432 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.18 state:D stack:27448 pid:6432 tgid:6430 ppid:6411 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14b8/0x4f90 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x161/0x360 kernel/sched/core.c:6960
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:7017
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x6f2/0x1470 kernel/locking/mutex.c:776
sync_bdevs+0x27a/0x470 block/bdev.c:1305
ksys_sync+0xb5/0x150 fs/sync.c:105
__ia32_sys_sync+0xa/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x86/0x12e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f55cb38f749
RSP: 002b:00007f55cc2d6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f55cb5e6090 RCX: 00007f55cb38f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f55cb5e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f55cb5e6128 R14: 00007f55cb5e6090 R15: 00007ffd49efb978
INFO: task syz.1.18:6432 is blocked on a mutex likely owned by task udevd:6143.
task:udevd state:D stack:21864 pid:6143 tgid:6143 ppid:5173 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14b8/0x4f90 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x161/0x360 kernel/sched/core.c:6960
io_schedule+0x7d/0xd0 kernel/sched/core.c:7789
folio_wait_bit_common+0x7a5/0xb70 mm/filemap.c:1323
folio_wait_bit_killable mm/filemap.c:1468 [inline]
folio_wait_locked_killable include/linux/pagemap.h:1241 [inline]
filemap_read_folio+0x1ff/0x370 mm/filemap.c:2502
do_read_cache_folio+0x358/0x590 mm/filemap.c:4096
read_mapping_folio include/linux/pagemap.h:1017 [inline]
read_part_sector+0xb2/0x2a0 block/partitions/core.c:722
adfspart_check_ICS+0xa0/0xa50 block/partitions/acorn.c:360
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x759/0x14a0 block/partitions/core.c:693
blkdev_get_whole+0x380/0x510 block/bdev.c:765
bdev_open+0x31a/0xd30 block/bdev.c:974
blkdev_open+0x453/0x5f0 block/fops.c:698
do_dentry_open+0x7cc/0x1420 fs/open.c:962
vfs_open+0x37/0x340 fs/open.c:1094
do_open fs/namei.c:4628 [inline]
path_openat+0x3406/0x3dc0 fs/namei.c:4787
do_filp_open+0x1f6/0x400 fs/namei.c:4814
do_sys_openat2+0x11d/0x200 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x134/0x160 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x86/0x12e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f6c6d3e0407
RSP: 002b:00007ffd051649b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f6c6d354880 RCX: 00007f6c6d3e0407
RDX: 00000000000a0800 RSI: 0000559d033d1170 RDI: ffffffffffffff9c
RBP: 0000559d033bf910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000559d033dcf10
R13: 0000559d033cd190 R14: 0000000000000000 R15: 0000559d033dcf10
Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/31:
#0: ffffffff8dd3ee40 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8dd3ee40 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8dd3ee40 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2a/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5564:
#0: ffff88814e1ad0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x445/0x1450 drivers/tty/n_tty.c:2211
1 lock held by udevd/6126:
#0: ffff8881427a9358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xdc/0xd30 block/bdev.c:962
1 lock held by udevd/6143:
#0: ffff888142770358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xdc/0xd30 block/bdev.c:962
1 lock held by syz.0.17/6362:
#0: ffff888142770358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27a/0x470 block/bdev.c:1305
1 lock held by syz.1.18/6432:
#0: ffff888142770358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27a/0x470 block/bdev.c:1305
1 lock held by udevd/6436:
#0: ffff8881427ab358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xdc/0xd30 block/bdev.c:962
1 lock held by syz.2.19/6455:
#0: ffff8881427ab358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27a/0x470 block/bdev.c:1305
1 lock held by udevd/6465:
#0: ffff888024657358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xdc/0xd30 block/bdev.c:962
1 lock held by udevd/6466:
#0: ffff888142779358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xdc/0xd30 block/bdev.c:962
1 lock held by syz.3.20/6485:
#0: ffff888024657358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27a/0x470 block/bdev.c:1305
1 lock held by syz.4.21/6513:
#0: ffff888142779358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27a/0x470 block/bdev.c:1305
1 lock held by udevd/6518:
#0: ffff8880246af358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xdc/0xd30 block/bdev.c:962
1 lock held by udevd/6519:
#0: ffff88814277b358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xdc/0xd30 block/bdev.c:962
1 lock held by syz.5.22/6544:
#0: ffff888142779358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27a/0x470 block/bdev.c:1305
1 lock held by syz.6.23/6576:
#0: ffff8880246af358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27a/0x470 block/bdev.c:1305
1 lock held by udevd/6583:
#0: ffff8880248ab358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xdc/0xd30 block/bdev.c:962
1 lock held by udevd/6584:
#0: ffff8880248db358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xdc/0xd30 block/bdev.c:962
1 lock held by syz.7.24/6610:
#0: ffff8880246af358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27a/0x470 block/bdev.c:1305
1 lock held by syz.8.25/6643:
#0: ffff8880248db358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27a/0x470 block/bdev.c:1305
1 lock held by udevd/6645:
#0: ffff8880248af358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xdc/0xd30 block/bdev.c:962
1 lock held by syz.9.26/6675:
#0: ffff8880248af358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27a/0x470 block/bdev.c:1305
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x185/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39a/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x176/0x2e0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x131/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0x17e1/0x1830 kernel/hung_task.c:515
kthread+0x70d/0x890 kernel/kthread.c:463
ret_from_fork+0x591/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 2065 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:lock_acquire+0xbc/0x340 kernel/locking/lockdep.c:5864
Code: ac 10 85 c0 0f 85 eb 00 00 00 65 48 8b 04 25 08 80 49 92 83 b8 34 0b 00 00 00 0f 85 d5 00 00 00 48 c7 44 24 30 00 00 00 00 9c <8f> 44 24 30 4c 89 74 24 10 4d 89 fe 4c 8b 7c 24 30 fa 48 c7 c7 a7
RSP: 0018:ffffc900052a6db0 EFLAGS: 00000246
RAX: ffff888028e10000 RBX: 0000000000000000 RCX: ccce7b58a251c900
RDX: 0000000000000000 RSI: ffffffff8173c08e RDI: 1ffffffff1ba7dc8
RBP: ffffffff8173c071 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc900052a6f78 R11: ffffffff81ac9430 R12: 0000000000000002
R13: ffffffff8dd3ee40 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126488000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffeee17cf52 CR3: 0000000078d2a000 CR4: 00000000003526f0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xbe/0x23c0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x118/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
save_stack+0xf3/0x1f0 mm/page_owner.c:165
__set_page_owner+0x89/0x4b0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x224/0x270 mm/page_alloc.c:1846
prep_new_page mm/page_alloc.c:1854 [inline]
get_page_from_freelist+0x239c/0x2470 mm/page_alloc.c:3915
__alloc_frozen_pages_noprof+0x17d/0x370 mm/page_alloc.c:5210
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
alloc_slab_page mm/slub.c:3075 [inline]
allocate_slab+0x86/0x3a0 mm/slub.c:3248
new_slab mm/slub.c:3302 [inline]
___slab_alloc+0xed1/0x1900 mm/slub.c:4656
__slab_alloc+0x65/0x100 mm/slub.c:4779
__slab_alloc_node mm/slub.c:4855 [inline]
slab_alloc_node mm/slub.c:5251 [inline]
__do_kmalloc_node mm/slub.c:5656 [inline]
__kmalloc_node_track_caller_noprof+0x5b4/0x7f0 mm/slub.c:5764
kmalloc_reserve+0x136/0x290 net/core/skbuff.c:608
__alloc_skb+0x27a/0x430 net/core/skbuff.c:690
alloc_skb include/linux/skbuff.h:1383 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:818 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:875 [inline]
nsim_dev_trap_report_work+0x296/0xb80 drivers/net/netdevsim/dev.c:921
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xacd/0x1750 kernel/workqueue.c:3340
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3421
kthread+0x70d/0x890 kernel/kthread.c:463
ret_from_fork+0x591/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246