INFO: task syz.0.855:9905 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.855 state:D stack:27816 pid:9905 tgid:9904 ppid:5808 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x60e0 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
bdev_open+0x41a/0xe40 block/bdev.c:961
blkdev_open+0x34e/0x4f0 block/fops.c:698
do_dentry_open+0x6d8/0x1660 fs/open.c:949
vfs_open+0x82/0x3f0 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x208c/0x31a0 fs/namei.c:4830
do_file_open+0x20e/0x430 fs/namei.c:4859
do_sys_openat2+0x10d/0x1e0 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3090b5cece
RSP: 002b:00007f308edf5b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f308edf66c0 RCX: 00007f3090b5cece
RDX: 0000000000000000 RSI: 00007f308edf5c00 RDI: ffffffffffffff9c
RBP: 00007f308edf5c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f3090e16038 R14: 00007f3090e15fa0 R15: 00007ffd59c560a8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by getty/5570:
#0: ffff88803942a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
1 lock held by udevd/5798:
#0: ffff888027d33358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
1 lock held by syz.0.855/9905:
#0: ffff888027d33358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
2 locks held by kworker/u8:7/10628:
4 locks held by syz-executor/11970:
1 lock held by syz.2.1173/11981:
2 locks held by sed/11983:
11 locks held by syz.4.1177/11995:
1 lock held by syz-executor/11994:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5161 Comm: syslogd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:unwind_next_frame+0x36/0x1ea0 arch/x86/kernel/unwind_orc.c:487
Code: ff df 41 57 48 89 fa 41 56 48 c1 ea 03 41 55 49 89 fd 41 54 55 53 48 83 ec 38 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 15 0c 00 00 <41> 8b 5d 00 31 ed 85 db 75 15 48 83 c4 38 89 e8 5b 5d 41 5c 41 5d
RSP: 0018:ffffc90005acf520 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc90005acf590 RCX: ffffc90005acf4e4
RDX: 1ffff92000b59eb2 RSI: ffffffff8a2fc584 RDI: ffffc90005acf590
RBP: ffffc90005acf620 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 00000000000859fb R12: ffffffff81f325b0
R13: ffffc90005acf590 R14: 0000000000000000 R15: ffff888037990000
FS: 00007f72bceb8c80(0000) GS:ffff88812434a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f32f0746368 CR3: 0000000021748000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2687 [inline]
slab_free mm/slub.c:6124 [inline]
kfree+0x1f6/0x6b0 mm/slub.c:6442
skb_kfree_head net/core/skbuff.c:1089 [inline]
skb_free_head+0x119/0x220 net/core/skbuff.c:1101
skb_release_data+0x79b/0x9d0 net/core/skbuff.c:1128
skb_release_all net/core/skbuff.c:1203 [inline]
__kfree_skb net/core/skbuff.c:1217 [inline]
consume_skb net/core/skbuff.c:1450 [inline]
consume_skb+0xc4/0x110 net/core/skbuff.c:1444
__unix_dgram_recvmsg+0x754/0xc30 net/unix/af_unix.c:2653
unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2670
sock_recvmsg_nosec net/socket.c:1078 [inline]
sock_recvmsg+0x1f9/0x250 net/socket.c:1100
sock_read_iter+0x2c6/0x3c0 net/socket.c:1170
new_sync_read fs/read_write.c:493 [inline]
vfs_read+0x957/0xb30 fs/read_write.c:574
ksys_read+0x1f8/0x250 fs/read_write.c:717
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f72bd008407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffd5189ce90 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f72bceb8c80 RCX: 00007f72bd008407
RDX: 00000000000000ff RSI: 00005626e956a300 RDI: 0000000000000000
RBP: 00005626e956a2c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00005626e956a34f
R13: 0000000000000000 R14: 00005626e956a300 R15: 00005626ac1f0d98