rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5967/1:b..l P6014/1:b..l P5201/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=12549, q=962 ncpus=2)
task:udevd state:R running task stack:25136 pid:5201 tgid:5201 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:memset_orig+0x0/0xb0 arch/x86/lib/memset_64.S:49
Code: 49 89 f9 40 88 f0 48 89 d1 f3 aa 4c 89 c8 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <49> 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01 48 0f af c1 41
RSP: 0018:ffffc90002f772f0 EFLAGS: 00000202
RAX: ffffc90002f77a01 RBX: ffffc90002f77400 RCX: ffffffff81743d8e
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90002f77418
RBP: dffffc0000000000 R08: ffffc90002f77427 R09: 1ffff920005eee84
R10: dffffc0000000000 R11: fffff520005eee85 R12: ffffc90002f77418
R13: 1ffff920005eee7b R14: ffffc90002f773c8 R15: ffffc90002f77410
unwind_next_frame+0xeae/0x23d0 arch/x86/kernel/unwind_orc.c:607
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:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5267 [inline]
kmem_cache_alloc_lru_noprof+0x36c/0x6e0 mm/slub.c:5286
__d_alloc+0x37/0x6f0 fs/dcache.c:1730
d_alloc_parallel+0xe1/0x1610 fs/dcache.c:2594
__lookup_slow+0x116/0x3d0 fs/namei.c:1843
lookup_slow+0x53/0x70 fs/namei.c:1875
walk_component fs/namei.c:2221 [inline]
lookup_last fs/namei.c:2722 [inline]
path_lookupat+0x3f5/0x8c0 fs/namei.c:2746
filename_lookup+0x212/0x570 fs/namei.c:2775
do_readlinkat+0xd9/0x500 fs/stat.c:576
__do_sys_readlink fs/stat.c:613 [inline]
__se_sys_readlink fs/stat.c:610 [inline]
__x64_sys_readlink+0x7f/0x90 fs/stat.c:610
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: 0033:0x7f313a1153a7
RSP: 002b:00007ffc1f9f0a98 EFLAGS: 00000202 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007ffc1f9f0ca0 RCX: 00007f313a1153a7
RDX: 0000000000000200 RSI: 00007ffc1f9f0aa0 RDI: 00007ffc1f9f0ca0
RBP: 0000562c8027d910 R08: 0000000000000064 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffc1f9f0aa0
R13: 0000562c4cee3100 R14: 0000000000000000 R15: 00007ffc1f9f12d0
task:udevd state:R running task stack:23416 pid:6014 tgid:6014 ppid:5201 task_flags:0x20440140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7050
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7074
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
_raw_spin_unlock_irq+0x45/0x50 kernel/locking/spinlock.c:202
spin_unlock_irq include/linux/spinlock.h:401 [inline]
loop_queue_work drivers/block/loop.c:864 [inline]
loop_queue_rq+0x9f8/0xb00 drivers/block/loop.c:1890
__blk_mq_issue_directly block/blk-mq.c:2715 [inline]
blk_mq_request_issue_directly+0x3c1/0x710 block/blk-mq.c:2802
blk_mq_issue_direct+0x2a0/0x660 block/blk-mq.c:2823
blk_mq_dispatch_queue_requests+0x6fe/0x800 block/blk-mq.c:2898
blk_mq_flush_plug_list+0x432/0x550 block/blk-mq.c:2981
__blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1225
blk_finish_plug+0x5e/0x90 block/blk-core.c:1252
read_pages+0x3b2/0x580 mm/readahead.c:176
page_cache_ra_unbounded+0x750/0x990 mm/readahead.c:302
do_page_cache_ra mm/readahead.c:332 [inline]
force_page_cache_ra mm/readahead.c:361 [inline]
page_cache_sync_ra+0x433/0xc40 mm/readahead.c:579
filemap_get_pages+0x468/0x1dc0 mm/filemap.c:2690
filemap_read+0x3f6/0x11a0 mm/filemap.c:2800
blkdev_read_iter+0x30a/0x440 block/fops.c:856
new_sync_read fs/read_write.c:491 [inline]
vfs_read+0x55a/0xa30 fs/read_write.c:572
ksys_read+0x145/0x250 fs/read_write.c:715
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: 0033:0x7f313a0a7407
RSP: 002b:00007ffc1f9eb9a0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f313a881880 RCX: 00007f313a0a7407
RDX: 0000000000000200 RSI: 00007f313a86b000 RDI: 0000000000000009
RBP: 0000562c8028b050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000018
R13: 0000000000200000 R14: 0000562c802a3478 R15: 00007f313a9a839c
task:udevd state:R running task stack:24472 pid:5967 tgid:5967 ppid:5201 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x2a6/0x3b0 kernel/locking/lockdep.c:5893
Code: 4d 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 52 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 2a 0f 01 11 <48> 3b 44 24 28 75 75 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d e9
RSP: 0018:ffffc90004c473b0 EFLAGS: 00000206
RAX: 5f955ebe741f2e00 RBX: 0000000000000202 RCX: 5f955ebe741f2e00
RDX: 0000000000000001 RSI: ffffffff8db7ed49 RDI: ffffffff8be07960
RBP: ffff88807d6a4858 R08: ffffc90004c47880 R09: 0000000000000000
R10: ffffc90004c47538 R11: fffff52000988ea9 R12: 0000000000000001
R13: 0000000000000001 R14: ffffffff8e13f2e0 R15: ffff88807d6a3d00
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0x1ab1/0x23d0 arch/x86/kernel/unwind_orc.c:695
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:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5267 [inline]
kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5274
mt_alloc_one lib/maple_tree.c:174 [inline]
mas_alloc_nodes+0x291/0x350 lib/maple_tree.c:1110
mas_wr_preallocate lib/maple_tree.c:3952 [inline]
mas_store_gfp+0x3a2/0x800 lib/maple_tree.c:5126
vma_iter_clear_gfp include/linux/mm.h:1142 [inline]
do_vmi_align_munmap+0x2af/0x440 mm/vma.c:1534
do_vmi_munmap+0x253/0x2e0 mm/vma.c:1587
__vm_munmap+0x207/0x380 mm/vma.c:3203
__do_sys_munmap mm/mmap.c:1077 [inline]
__se_sys_munmap mm/mmap.c:1074 [inline]
__x64_sys_munmap+0x60/0x70 mm/mmap.c:1074
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: 0033:0x7f313a11e097
RSP: 002b:00007ffc1f9ebb68 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 0000562c8029bfa0 RCX: 00007f313a11e097
RDX: 0000562c80288648 RSI: 0000000000000200 RDI: 00007f313a874000
RBP: 000000000000000b R08: 0000562c80298780 R09: 0000000000000003
R10: 0000000000000010 R11: 0000000000000246 R12: 0000562c8028b0b0
R13: 00007f313a9a839c R14: 0000000000001600 R15: 0000000000000009
rcu: rcu_preempt kthread starved for 720 jiffies! g12549 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
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
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 9e 2a 00 f3 0f 1e fa fb f4 48 ee 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: 3d61b0fea8c2e400 RBX: ffffffff819786ba RCX: 3d61b0fea8c2e400
RDX: 0000000000000001 RSI: ffffffff8d997e54 RDI: ffffffff8be07960
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8fa22f70
R13: 1ffff11003b56b70 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd2e11ffe00 CR3: 000000002f44c000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1ea/0x520 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147