rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7586/1:b..l
rcu: (detected by 0, t=10663 jiffies, g=24501, q=622 ncpus=2)
task:syz.2.396 state:R running task stack:21240 pid:7586 tgid:7586 ppid:5598 task_flags:0x440e40 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7284
preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:7606
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x205/0xa10 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_release+0x13/0x310 kernel/locking/lockdep.c:5951
Code: 24 14 eb 98 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 41 54 55 53 48 89 fb 48 83 ec 18 <65> 48 8b 2d ad 95 a5 12 48 89 6c 24 10 48 89 f5 0f 1f 44 00 00 65
RSP: 0018:ffffc9001aade160 EFLAGS: 00000286
RAX: 0000000000000000 RBX: ffffffff8edec5a0 RCX: 0000000000000000
RDX: ffff888030c62580 RSI: ffffffff82582a27 RDI: ffffffff8edec5a0
RBP: ffff88803800b320 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000001
R13: 0000000000000001 R14: 0000000000000020 R15: dffffc0000000000
rcu_lock_release include/linux/rcupdate.h:319 [inline]
rcu_read_unlock include/linux/rcupdate.h:880 [inline]
shrink_slab_memcg mm/shrinker.c:552 [inline]
shrink_slab+0xa5c/0x12e0 mm/shrinker.c:640
shrink_node_memcgs mm/vmscan.c:6222 [inline]
shrink_node+0x812/0x4320 mm/vmscan.c:6264
shrink_zones mm/vmscan.c:6503 [inline]
do_try_to_free_pages+0x33e/0x16d0 mm/vmscan.c:6565
try_to_free_mem_cgroup_pages+0x2bf/0x840 mm/vmscan.c:6887
try_charge_memcg+0x50b/0xf60 mm/memcontrol.c:2718
charge_memcg+0x1ae/0x210 mm/memcontrol.c:5210
__mem_cgroup_charge+0x2b/0x1c0 mm/memcontrol.c:5227
mem_cgroup_charge include/linux/memcontrol.h:662 [inline]
filemap_add_folio+0xe7/0x640 mm/filemap.c:965
page_cache_ra_unbounded+0x37a/0x990 mm/readahead.c:293
do_page_cache_ra+0x10f/0x160 mm/readahead.c:348
page_cache_ra_order+0xc05/0xed0 mm/readahead.c:558
do_sync_mmap_readahead mm/filemap.c:3443 [inline]
filemap_fault+0x1943/0x3130 mm/filemap.c:3597
__do_fault+0x10b/0x440 mm/memory.c:5565
do_read_fault mm/memory.c:6000 [inline]
do_fault+0xb3f/0x1830 mm/memory.c:6134
do_pte_missing mm/memory.c:4700 [inline]
handle_pte_fault mm/memory.c:6558 [inline]
__handle_mm_fault+0x150b/0x2f60 mm/memory.c:6707
handle_mm_fault+0x363/0xa20 mm/memory.c:6876
faultin_page mm/gup.c:1126 [inline]
__get_user_pages+0x8ae/0x2c30 mm/gup.c:1428
__get_user_pages_locked mm/gup.c:1692 [inline]
get_dump_page+0x27e/0x3d0 mm/gup.c:2192
dump_user_range+0x18d/0xad0 fs/coredump.c:1361
elf_core_dump+0x2d68/0x3d20 fs/binfmt_elf.c:2106
coredump_write fs/coredump.c:1047 [inline]
do_coredump fs/coredump.c:1126 [inline]
vfs_coredump+0x281a/0x54a0 fs/coredump.c:1195
get_signal+0x1f2a/0x21e0 kernel/signal.c:3097
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop kernel/entry/common.c:101 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
irqentry_exit+0x402/0xa10 kernel/entry/common.c:165
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f8b8d79e161
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f8b8da25fa0 RCX: 00007f8b8d79e159
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f8b8d83506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f8b8da26038 R14: 00007f8b8da25fa0 R15: 00007fffd369bfc8
rcu: rcu_preempt kthread starved for 9847 jiffies! g24501 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:29048 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7376
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x8f0 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x17a/0x220 kernel/rcu/tree.c:2330
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7623 Comm: syz.4.423 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:check_preemption_disabled+0x0/0xe0 lib/smp_processor_id.c:13
Code: c0 75 0f 65 8b 05 c4 c8 ba 08 85 c0 74 04 90 0f 0b 90 e9 53 fc ff ff 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <41> 54 55 53 48 83 ec 08 65 8b 15 89 86 ba 08 65 8b 2d 92 86 ba 08
RSP: 0018:ffffc9001af6e358 EFLAGS: 00000283
RAX: 0000000000000001 RBX: ffffffff8edec5a0 RCX: 0000000000000000
RDX: ffff888031db2580 RSI: ffffffff8c623900 RDI: ffffffff8c623940
RBP: ffffffff825f7af7 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000006
R13: ffff88801da8ee00 R14: 0000000000000000 R15: ffffc9001af6e580
FS: 00007f50be62d6c0(0000) GS:ffff888123c4f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f115d5384f0 CR3: 000000007e3a9000 CR4: 00000000003526f0
Call Trace:
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x13/0xc0 kernel/rcu/tree.c:753
trace_lock_release include/trace/events/lock.h:68 [inline]
lock_release+0x24d/0x310 kernel/locking/lockdep.c:5954
rcu_lock_release include/linux/rcupdate.h:319 [inline]
rcu_read_unlock include/linux/rcupdate.h:880 [inline]
list_lru_count_one+0x14c/0x320 mm/list_lru.c:318
list_lru_shrink_count include/linux/list_lru.h:260 [inline]
super_cache_count+0x174/0x290 fs/super.c:267
do_shrink_slab+0x83/0x1200 mm/shrinker.c:391
shrink_slab_memcg mm/shrinker.c:562 [inline]
shrink_slab+0xa82/0x12e0 mm/shrinker.c:640
shrink_node_memcgs mm/vmscan.c:6222 [inline]
shrink_node+0x812/0x4320 mm/vmscan.c:6264
shrink_zones mm/vmscan.c:6503 [inline]
do_try_to_free_pages+0x33e/0x16d0 mm/vmscan.c:6565
try_to_free_mem_cgroup_pages+0x2bf/0x840 mm/vmscan.c:6887
try_charge_memcg+0x50b/0xf60 mm/memcontrol.c:2718
charge_memcg+0x1ae/0x210 mm/memcontrol.c:5210
__mem_cgroup_charge+0x2b/0x1c0 mm/memcontrol.c:5227
mem_cgroup_charge include/linux/memcontrol.h:662 [inline]
shmem_alloc_and_add_folio+0x451/0xd40 mm/shmem.c:1988
shmem_get_folio_gfp+0x75b/0x1980 mm/shmem.c:2531
shmem_get_folio mm/shmem.c:2637 [inline]
shmem_write_begin+0x1a4/0x420 mm/shmem.c:3268
generic_perform_write+0x292/0xa40 mm/filemap.c:4374
shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3443
__kernel_write_iter+0x2ac/0x930 fs/read_write.c:621
dump_emit_page fs/coredump.c:1293 [inline]
dump_user_range+0x3f9/0xad0 fs/coredump.c:1367
elf_core_dump+0x2d68/0x3d20 fs/binfmt_elf.c:2106
coredump_write fs/coredump.c:1047 [inline]
do_coredump fs/coredump.c:1126 [inline]
vfs_coredump+0x281a/0x54a0 fs/coredump.c:1195
get_signal+0x1f2a/0x21e0 kernel/signal.c:3097
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop kernel/entry/common.c:101 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
irqentry_exit+0x402/0xa10 kernel/entry/common.c:165
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f50bd79e161
Code: 00 00 00 00 0f 1f 44 00 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 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f50bda26090 RCX: 00007f50bd79e159
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f50bd83506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f50bda26128 R14: 00007f50bda26090 R15: 00007ffeec1216a8