INFO: task syz.0.16:6538 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.16 state:D stack:28936 pid:6538 tgid:6528 ppid:6436 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1dfe/0x25e0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244
inode_lock_nested include/linux/fs.h:1072 [inline]
lock_rename fs/namei.c:3712 [inline]
__start_renaming+0x148/0x410 fs/namei.c:3808
do_renameat2+0x399/0x8f0 fs/namei.c:6022
__do_sys_rename fs/namei.c:6090 [inline]
__se_sys_rename fs/namei.c:6088 [inline]
__x64_sys_rename+0x82/0x90 fs/namei.c:6088
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5474dce969
RSP: 002b:00007f547401d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007f5474ff6080 RCX: 00007f5474dce969
RDX: 0000000000000000 RSI: 0000200000000180 RDI: 00002000000003c0
RBP: 00007f5474e50ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f5474ff6080 R15: 00007ffea797e5f8
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d5ae880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5ae880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5ae880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5564:
#0: ffff888034bc80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211
4 locks held by syz.0.16/6529:
2 locks held by syz.0.16/6538:
#0: ffff88802c78a480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff888041df1098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff888041df1098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3712 [inline]
#1: ffff888041df1098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3808
3 locks held by syz.1.17/6605:
2 locks held by syz.1.17/6609:
#0: ffff888034a00480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff88802206a868 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff88802206a868 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3712 [inline]
#1: ffff88802206a868 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3808
3 locks held by syz.2.18/6637:
2 locks held by syz.2.18/6641:
#0: ffff8880497b2480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff888058e99098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff888058e99098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3712 [inline]
#1: ffff888058e99098 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3808
3 locks held by syz.3.19/6665:
2 locks held by syz.3.19/6669:
#0: ffff888036c52480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff888058e9a868 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff888058e9a868 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3712 [inline]
#1: ffff888058e9a868 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3808
4 locks held by syz.4.20/6702:
2 locks held by syz.4.20/6708:
#0: ffff88803aace480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff888041cfd808 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff888041cfd808 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3712 [inline]
#1: ffff888041cfd808 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3808
3 locks held by syz.5.21/6742:
2 locks held by syz.5.21/6746:
#0: ffff88802eb72480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff888058cf3450 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff888058cf3450 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3712 [inline]
#1: ffff888058cf3450 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3808
4 locks held by syz.6.22/6777:
2 locks held by syz.6.22/6781:
#0: ffff888030cf0480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff888058dd4c20 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
#1: ffff888058dd4c20 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3712 [inline]
#1: ffff888058dd4c20 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3808
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6637 Comm: syz.2.18 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:107 [inline]
RIP: 0010:raw_atomic_try_cmpxchg include/linux/atomic/atomic-arch-fallback.h:2130 [inline]
RIP: 0010:raw_atomic_fetch_add_unless include/linux/atomic/atomic-arch-fallback.h:2431 [inline]
RIP: 0010:raw_atomic_add_unless include/linux/atomic/atomic-arch-fallback.h:2456 [inline]
RIP: 0010:raw_atomic_inc_not_zero include/linux/atomic/atomic-arch-fallback.h:2477 [inline]
RIP: 0010:atomic_inc_not_zero include/linux/atomic/atomic-instrumented.h:1537 [inline]
RIP: 0010:__entry_find+0x226/0x410 fs/mbcache.c:171
Code: ff 45 85 f6 74 35 41 8d 4e 01 31 f6 44 89 f0 f0 41 0f b1 4d 00 41 0f 94 c4 40 0f 94 c6 41 89 c6 bf 02 00 00 00 e8 ca 8c 71 ff <45> 84 e4 75 63 45 85 f6 74 57 e8 6b 89 71 ff eb cb e8 64 89 71 ff
RSP: 0018:ffffc900046ff590 EFLAGS: 00000293
RAX: ffffffff824ed946 RBX: 0000000000000000 RCX: ffff888035b01e40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100611fc26 R12: 00000000aae05e01
R13: ffff8880308fe128 R14: 0000000000000001 R15: ffff8880308fe118
FS: 00007fba95f0e6c0(0000) GS:ffff888126d03000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555645b35c8 CR3: 0000000042404000 CR4: 00000000003526f0
Call Trace:
ext4_xattr_block_cache_find fs/ext4/xattr.c:3115 [inline]
ext4_xattr_block_set+0x9ed/0x2ac0 fs/ext4/xattr.c:2038
ext4_xattr_set_handle+0xdfb/0x1590 fs/ext4/xattr.c:2456
ext4_initxattrs+0x9f/0x110 fs/ext4/xattr_security.c:44
security_inode_init_security+0x290/0x3d0 security/security.c:1344
__ext4_new_inode+0x32f7/0x3c90 fs/ext4/ialloc.c:1324
ext4_create+0x22d/0x460 fs/ext4/namei.c:2820
vfs_create+0x3b2/0x410 fs/namei.c:4132
do_mknodat+0x3ee/0x620 fs/namei.c:5039
__do_sys_mknodat fs/namei.c:5071 [inline]
__se_sys_mknodat fs/namei.c:5068 [inline]
__x64_sys_mknodat+0xa7/0xc0 fs/namei.c:5068
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fba96c9e969
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:00007fba95f0e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000103
RAX: ffffffffffffffda RBX: 00007fba96ec5fa0 RCX: 00007fba96c9e969
RDX: 0000000000000400 RSI: 0000200000000180 RDI: 0000000000000004
RBP: 00007fba96d20ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000103 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fba96ec5fa0 R15: 00007ffea1016ea8