rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5826/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=9349, q=4088 ncpus=2)
task:syz-executor234 state:R running task stack:26368 pid:5826 tgid:5826 ppid:5823 task_flags:0x440140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6894
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221
irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5945
Code: 18 00 00 b8 ff ff ff ff 65 0f c1 05 a3 b0 44 07 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 90 0f 0b 90 48 c7
RSP: 0018:ffffc900040df788 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000046
RDX: ffff8880776e0000 RSI: ffffffff8db82ed3 RDI: ffffffff8be085e0
RBP: 00000000ffffffff R08: ffffffff8258e247 R09: ffffffff8e13efa0
R10: 0000000000008000 R11: 0000000000000000 R12: 0000000000000246
R13: ffff8880776e0000 R14: ffffffff8e13efa0 R15: 0000000000000003
get_cached_acl+0x1b7/0x510 fs/posix_acl.c:53
__get_acl+0x84/0x400 fs/posix_acl.c:128
get_inode_acl fs/posix_acl.c:184 [inline]
posix_acl_create+0x134/0x4a0 fs/posix_acl.c:646
ext4_init_acl+0xb3/0x320 fs/ext4/acl.c:284
__ext4_new_inode+0x31fb/0x3c90 fs/ext4/ialloc.c:1320
ext4_mkdir+0x3cb/0xc50 fs/ext4/namei.c:3005
vfs_mkdir+0x414/0x630 fs/namei.c:5196
do_mkdirat+0x276/0x500 fs/namei.c:5230
__do_sys_mkdir fs/namei.c:5257 [inline]
__se_sys_mkdir fs/namei.c:5255 [inline]
__x64_sys_mkdir+0x6c/0x80 fs/namei.c:5255
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f939d019657
RSP: 002b:00007ffe35562b48 EFLAGS: 00000206 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f939d0720ae RCX: 00007f939d019657
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 00007f939d0720ae
RBP: 00007ffe35562bf0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007f939d07833c
R13: 0000000000000004 R14: 0000000000000004 R15: 0000000000000001
rcu: rcu_preempt kthread starved for 10234 jiffies! g9349 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:R running task stack:28080 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6894
__schedule_loop kernel/sched/core.c:6976 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6991
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297
kthread+0x389/0x480 kernel/kthread.c:467
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5856 Comm: syz-executor234 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:in_irqentry_text kernel/stacktrace.c:381 [inline]
RIP: 0010:filter_irq_stacks+0x56/0xa0 kernel/stacktrace.c:397
Code: 03 42 80 3c 28 00 74 08 4c 89 ff e8 d4 c7 7a 00 49 8b 04 de 48 3d 30 02 00 81 0f 93 c1 48 3d 90 16 00 81 0f 92 c2 84 d1 75 27 <48> 3d 10 c4 5f 8b 0f 92 c1 48 3d 2b c4 5f 8b 0f 93 c0 08 c8 74 11
RSP: 0018:ffffc9000429f368 EFLAGS: 00000246
RAX: ffffffff850f8617 RBX: 0000000000000003 RCX: 0000000000000001
RDX: 0000000000000c00 RSI: 000000000000000d RDI: ffffc9000429f3f0
RBP: ffffc9000429f618 R08: ffffffff81cfe626 R09: ffffffff8e13efa0
R10: ffffc9000429f2f8 R11: ffffffff81acb3b0 R12: 000000000000000d
R13: dffffc0000000000 R14: ffffc9000429f3f0 R15: ffffc9000429f408
FS: 0000555575e003c0(0000) GS:ffff888125c0a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000100 CR3: 0000000031cd6000 CR4: 00000000003526f0
Call Trace:
stack_depot_save_flags+0x33/0x810 lib/stackdepot.c:667
kasan_save_stack mm/kasan/common.c:58 [inline]
kasan_save_track+0x4f/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5780
kmalloc_noprof include/linux/slab.h:957 [inline]
tty_alloc_file drivers/tty/tty_io.c:186 [inline]
tty_open+0x947/0xd10 drivers/tty/tty_io.c:2114
chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414
do_dentry_open+0x785/0x14e0 fs/open.c:962
vfs_open+0x3b/0x340 fs/open.c:1094
do_open fs/namei.c:4627 [inline]
path_openat+0x2de0/0x3840 fs/namei.c:4786
do_filp_open+0x1fa/0x410 fs/namei.c:4813
do_sys_openat2+0x121/0x200 fs/open.c:1391
do_sys_open fs/open.c:1397 [inline]
__do_sys_openat fs/open.c:1413 [inline]
__se_sys_openat fs/open.c:1408 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1408
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f939d01a8d9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 19 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe35562988 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f939d072038 RCX: 00007f939d01a8d9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 0000000000000000 R08: 00007f939cfd2990 R09: 00007f939cfd2990
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f939d07833c
R13: 00007f939d072106 R14: 00007ffe355629c0 R15: 0000000000000000
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.172 msecs