INFO: task syz.0.17:6432 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17 state:D stack:27944 pid:6432 tgid:6428 ppid:6350 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
bfs_lookup+0xe3/0x1d0 fs/bfs/dir.c:136
__lookup_slow+0x297/0x3d0 fs/namei.c:1816
lookup_slow+0x53/0x70 fs/namei.c:1833
walk_component fs/namei.c:2151 [inline]
link_path_walk+0x935/0xea0 fs/namei.c:2519
path_parentat fs/namei.c:2723 [inline]
__filename_parentat+0x246/0x670 fs/namei.c:2747
filename_parentat fs/namei.c:2765 [inline]
filename_create+0xd2/0x3c0 fs/namei.c:4207
do_mkdirat+0xa0/0x590 fs/namei.c:4478
__do_sys_mkdirat fs/namei.c:4503 [inline]
__se_sys_mkdirat fs/namei.c:4501 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501
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: 0033:0x7f642998eba9
RSP: 002b:00007f642a820038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f6429bd6090 RCX: 00007f642998eba9
RDX: 00000000000001ff RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f6429a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6429bd6128 R14: 00007f6429bd6090 R15: 00007fff1a875fa8
INFO: task syz.1.18:6462 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:28360 pid:6462 tgid:6460 ppid:6441 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
bfs_lookup+0xe3/0x1d0 fs/bfs/dir.c:136
__lookup_slow+0x297/0x3d0 fs/namei.c:1816
lookup_slow+0x53/0x70 fs/namei.c:1833
walk_component fs/namei.c:2151 [inline]
link_path_walk+0x935/0xea0 fs/namei.c:2519
path_parentat fs/namei.c:2723 [inline]
__filename_parentat+0x246/0x670 fs/namei.c:2747
filename_parentat fs/namei.c:2765 [inline]
filename_create+0xd2/0x3c0 fs/namei.c:4207
do_mkdirat+0xa0/0x590 fs/namei.c:4478
__do_sys_mkdirat fs/namei.c:4503 [inline]
__se_sys_mkdirat fs/namei.c:4501 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501
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: 0033:0x7f51f678eba9
RSP: 002b:00007f51f7628038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f51f69d6090 RCX: 00007f51f678eba9
RDX: 00000000000001ff RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f51f6811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f51f69d6128 R14: 00007f51f69d6090 R15: 00007ffd971a5118
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8dd3a960 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8dd3a960 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8dd3a960 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:5/987:
2 locks held by getty/5592:
#0: ffff8880300520a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
6 locks held by syz.0.17/6429:
2 locks held by syz.0.17/6432:
#0: ffff888060aac160 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:994 [inline]
#0: ffff888060aac160 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832
#1: ffff888030a0ded8 (&info->bfs_lock){+.+.}-{4:4}, at: bfs_lookup+0xe3/0x1d0 fs/bfs/dir.c:136
3 locks held by syz.1.18/6461:
2 locks held by syz.1.18/6462:
#0: ffff888060aac670 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:994 [inline]
#0: ffff888060aac670 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832
#1: ffff888030ce0cd8 (&info->bfs_lock){+.+.}-{4:4}, at: bfs_lookup+0xe3/0x1d0 fs/bfs/dir.c:136
2 locks held by syz.2.19/6491:
2 locks held by syz.2.19/6492:
#0: ffff8880836f4160 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:994 [inline]
#0: ffff8880836f4160 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832
#1: ffff888078a82ad8 (&info->bfs_lock){+.+.}-{4:4}, at: bfs_lookup+0xe3/0x1d0 fs/bfs/dir.c:136
2 locks held by syz.3.20/6514:
2 locks held by syz.3.20/6515:
#0: ffff888060aacb80 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:994 [inline]
#0: ffff888060aacb80 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832
#1: ffff8880506b3ed8 (&info->bfs_lock){+.+.}-{4:4}, at: bfs_lookup+0xe3/0x1d0 fs/bfs/dir.c:136
3 locks held by syz.4.21/6546:
2 locks held by syz.4.21/6547:
#0: ffff8880836f4670 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:994 [inline]
#0: ffff8880836f4670 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832
#1: ffff8880505bd0d8 (&info->bfs_lock){+.+.}-{4:4}, at: bfs_lookup+0xe3/0x1d0 fs/bfs/dir.c:136
3 locks held by syz.5.22/6584:
2 locks held by syz.5.22/6585:
#0: ffff888060aad090 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:994 [inline]
#0: ffff888060aad090 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832
#1: ffff888050c5b2d8 (&info->bfs_lock){+.+.}-{4:4}, at: bfs_lookup+0xe3/0x1d0 fs/bfs/dir.c:136
3 locks held by syz.6.23/6616:
2 locks held by syz.6.23/6617:
#0: ffff8880836f4b80 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:994 [inline]
#0: ffff8880836f4b80 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832
#1: ffff8880505b68d8 (&info->bfs_lock){+.+.}-{4:4}, at: bfs_lookup+0xe3/0x1d0 fs/bfs/dir.c:136
3 locks held by syz.7.24/6648:
2 locks held by syz.7.24/6649:
#0: ffff888060aad5a0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:994 [inline]
#0: ffff888060aad5a0 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832
#1: ffff8880274d88d8 (&info->bfs_lock){+.+.}-{4:4}, at: bfs_lookup+0xe3/0x1d0 fs/bfs/dir.c:136
=============================================
NMI backtrace for cpu 1
CPU: 1 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+0x711/0x8a0 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 36 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:rcu_is_watching+0x72/0xb0 kernel/rcu/tree.c:753
Code: ff 4b 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d c9 ba a5 10 74 11 83 e0 04 c1 e8 02 5b 41 5e <41> 5f e9 92 2b 6b ff cc e8 41 12 8e ff eb e8 48 c7 c7 40 06 d4 8d
RSP: 0018:ffffc90000ac73c0 EFLAGS: 00000212
RAX: 0000000000000001 RBX: ffffffff8feb9101 RCX: 1fc4cfaf21f00300
RDX: ffffc90000ac7501 RSI: ffffffff8b9ec2c0 RDI: ffffffff8b9ec280
RBP: dffffc0000000000 R08: ffffc90000ac7c70 R09: ffffc90000ac7558
R10: dffffc0000000000 R11: fffff52000158ead R12: ffffc90000ac7c80
R13: ffffffff81725d05 R14: ffffffff8dd3a960 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888126373000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055da86875a38 CR3: 0000000032c89000 CR4: 0000000000350ef0
Call Trace:
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x4b/0x3e0 kernel/locking/lockdep.c:5879
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1169 [inline]
unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4376 [inline]
__kmalloc_node_track_caller_noprof+0x271/0x4e0 mm/slub.c:4395
kmalloc_reserve+0x136/0x290 net/core/skbuff.c:600
__alloc_skb+0x142/0x2d0 net/core/skbuff.c:669
alloc_skb include/linux/skbuff.h:1336 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:763 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
nsim_dev_trap_report_work+0x29a/0xb80 drivers/net/netdevsim/dev.c:866
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 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