INFO: task udevd:21121 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:22616 pid:21121 tgid:21121 ppid:5234 task_flags:0x400040 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
io_schedule+0x80/0xd0 kernel/sched/core.c:7903
folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317
folio_put_wait_locked mm/filemap.c:1481 [inline]
do_read_cache_folio+0x1aa/0x590 mm/filemap.c:3939
read_mapping_folio include/linux/pagemap.h:991 [inline]
read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
adfspart_check_POWERTEC+0x8c/0xf30 block/partitions/acorn.c:454
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
blkdev_get_whole+0x380/0x510 block/bdev.c:748
bdev_open+0x31e/0xd30 block/bdev.c:957
blkdev_open+0x457/0x600 block/fops.c:694
do_dentry_open+0x950/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4046
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f78d7aa7407
RSP: 002b:00007ffded5f61d0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f78d8232880 RCX: 00007f78d7aa7407
RDX: 00000000000a0800 RSI: 000055a7fee73600 RDI: ffffffffffffff9c
RBP: 000055a7fee4f910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055a7fee67e00
R13: 000055a7fee5d190 R14: 00007ffded5f6298 R15: 000055a7fee67e00
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u9:0/51:
2 locks held by getty/5623:
#0: ffff88814d2290a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036c32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/21121:
#0: ffff8880252d5358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
1 lock held by syz.2.13075/4656:
=============================================
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 08/18/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 4656 Comm: syz.2.13075 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:debug_check_no_obj_freed+0x0/0x470 lib/debugobjects.c:1127
Code: 80 c1 03 38 c1 0f 8c 2d ff ff ff 4c 89 ef e8 07 68 52 fd e9 20 ff ff ff 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <66> 0f 1f 00 55 41 57 41 56 41 55 41 54 53 48 81 ec 88 00 00 00 65
RSP: 0018:ffffc9000b277170 EFLAGS: 00000246
RAX: d64ed479d2b56900 RBX: 0000000000000000 RCX: ffffffff8e13a100
RDX: fffffffe1f0f9500 RSI: 00000000000000f0 RDI: ffff88805aef9500
RBP: ffff88805aef9500 R08: 0000000000000000 R09: 1ffffffff1f474c6
R10: dffffc0000000000 R11: fffffbfff1f474c7 R12: 0000000000000000
R13: ffff88801e2a48c0 R14: 0000000000000000 R15: 0000000000212110
FS: 00007f9f0f3f16c0(0000) GS:ffff888125d12000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003000 CR3: 000000007bdf2000 CR4: 00000000003526f0
Call Trace:
slab_free_hook mm/slub.c:2353 [inline]
slab_free_freelist_hook mm/slub.c:2451 [inline]
slab_free_bulk mm/slub.c:4719 [inline]
kmem_cache_free_bulk+0x248/0x520 mm/slub.c:5298
kfree_skb_list_reason+0x3eb/0x460 net/core/skbuff.c:1253
__dev_xmit_skb net/core/dev.c:4189 [inline]
__dev_queue_xmit+0x21d3/0x3b50 net/core/dev.c:4691
dev_queue_xmit include/linux/netdevice.h:3361 [inline]
__bpf_tx_skb+0x18e/0x260 net/core/filter.c:2153
____bpf_clone_redirect net/core/filter.c:2478 [inline]
bpf_clone_redirect+0x272/0x3d0 net/core/filter.c:2448
bpf_prog_b36a1f39e2fdd4f4+0x5f/0x68
bpf_dispatcher_nop_func include/linux/bpf.h:1332 [inline]
__bpf_prog_run include/linux/filter.h:718 [inline]
bpf_prog_run include/linux/filter.h:725 [inline]
bpf_test_run+0x318/0x7b0 net/bpf/test_run.c:434
bpf_prog_test_run_skb+0xb30/0x1560 net/bpf/test_run.c:1099
bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4590
__sys_bpf+0x581/0x870 kernel/bpf/syscall.c:6047
__do_sys_bpf kernel/bpf/syscall.c:6139 [inline]
__se_sys_bpf kernel/bpf/syscall.c:6137 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6137
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9f0e58eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9f0f3f1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f9f0e7e5fa0 RCX: 00007f9f0e58eec9
RDX: 0000000000000050 RSI: 00002000000000c0 RDI: 000000000000000a
RBP: 00007f9f0e611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9f0e7e6038 R14: 00007f9f0e7e5fa0 R15: 00007ffdf18cabf8