rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9336/1:b..l P5195/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=48129, q=635 ncpus=2)
task:udevd state:R running task stack:23000 pid:5195 tgid:5195 ppid:1 task_flags:0x400140 flags:0x00000002
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090
irqentry_exit+0x6f/0x90 kernel/entry/common.c:354
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5870
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 8b 9f d7 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900031bf3d8 EFLAGS: 00000206
RAX: 3eb16eef1e810800 RBX: 0000000000000000 RCX: 3eb16eef1e810800
RDX: 0000000000000000 RSI: ffffffff8d939072 RDI: ffffffff8bc1f600
RBP: ffffffff8171ca05 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8171ca05 R12: 0000000000000002
R13: ffffffff8df3dee0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
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
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2380 [inline]
slab_free mm/slub.c:4642 [inline]
kfree+0x193/0x440 mm/slub.c:4841
tomoyo_realpath_from_path+0x598/0x5d0 security/tomoyo/realpath.c:286
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:822
security_inode_getattr+0x12f/0x330 security/security.c:2377
vfs_getattr fs/stat.c:256 [inline]
vfs_statx_path fs/stat.c:296 [inline]
vfs_statx+0x153/0x550 fs/stat.c:353
vfs_fstatat+0xe4/0x160 fs/stat.c:372
__do_sys_newfstatat fs/stat.c:536 [inline]
__se_sys_newfstatat fs/stat.c:530 [inline]
__x64_sys_newfstatat+0x11c/0x1a0 fs/stat.c:530
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff5b6d11b0a
RSP: 002b:00007ffde28df578 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007ffde28dfa10 RCX: 00007ff5b6d11b0a
RDX: 00007ffde28df580 RSI: 00007ffde28dfa10 RDI: 00000000ffffff9c
RBP: 00005556b703d910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffde28df610
R13: 0000555678247100 R14: 0000000000000000 R15: 00007ffde28e0030
task:syz-executor state:R running task stack:17512 pid:9336 tgid:9336 ppid:9307 task_flags:0x400140 flags:0x00000000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6947
preempt_schedule+0xae/0xc0 kernel/sched/core.c:6971
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
copy_pte_range mm/memory.c:1194 [inline]
copy_pmd_range+0x673c/0x7000 mm/memory.c:1255
copy_pud_range mm/memory.c:1292 [inline]
copy_p4d_range mm/memory.c:1316 [inline]
copy_page_range+0x95c/0xd40 mm/memory.c:1410
dup_mmap kernel/fork.c:727 [inline]
dup_mm kernel/fork.c:1735 [inline]
copy_mm+0x126a/0x2160 kernel/fork.c:1787
copy_process+0x16d3/0x3b80 kernel/fork.c:2430
kernel_clone+0x21e/0x870 kernel/fork.c:2845
__do_sys_clone kernel/fork.c:2988 [inline]
__se_sys_clone kernel/fork.c:2972 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2972
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9591f851d3
RSP: 002b:00007ffd686ab3a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9591f851d3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 0000555594f567d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000005e6e3 R15: 00007ffd686ab540
rcu: rcu_preempt kthread starved for 10475 jiffies! g48129 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 12437 Comm: modprobe Not tainted 6.15.0-rc7-syzkaller-00144-gb1427432d3b6 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xe6e/0x11c0 kernel/smp.c:885
Code: 89 ee 83 e6 01 31 ff e8 80 6d 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 2b 69 0b 00 eb 37 f3 90 43 0f b6 04 2c <84> c0 75 10 41 f7 07 01 00 00 00 74 1e e8 10 69 0b 00 eb e5 44 89
RSP: 0018:ffffc9000c6b7700 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b883ad40 RCX: ffff88807ea4da00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000c6b7860 R08: ffffffff8f7f3577 R09: 1ffffffff1efe6ae
R10: dffffc0000000000 R11: fffffbfff1efe6af R12: 1ffff11017127e99
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b893f4c8
FS: 0000000000000000(0000) GS:ffff8881260c2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb6afdd7d58 CR3: 000000006cdda000 CR4: 0000000000350ef0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1291 [inline]
flush_tlb_mm_range+0x6ae/0x12b0 arch/x86/mm/tlb.c:1381
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:480 [inline]
tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:496
exit_mmap+0x474/0xba0 mm/mmap.c:1297
__mmput+0x118/0x420 kernel/fork.c:1380
exit_mm+0x1da/0x2c0 kernel/exit.c:589
do_exit+0x859/0x2550 kernel/exit.c:940
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
__do_sys_exit_group kernel/exit.c:1113 [inline]
__se_sys_exit_group kernel/exit.c:1111 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111
x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe73a1216c5
Code: Unable to access opcode bytes at 0x7fe73a12169b.
RSP: 002b:00007ffc6aae7a08 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fe73a222fe8 RCX: 00007fe73a1216c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000001
RBP: 0000000000000001 R08: 00007ffc6aae7998 R09: 0000000000000000
R10: 00007ffc6aae7830 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fe73a221680 R15: 00007fe73a223000