rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15304/1:b..l P15162/1:b..l P15156/1:b..l P15323/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=91425, q=1422 ncpus=2)
task:syz.2.1958 state:R running task stack:26984 pid:15323 tgid:15321 ppid:5829 task_flags:0x20400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7238
irqentry_exit+0x17b/0x670 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:get_current arch/x86/include/asm/current.h:23 [inline]
RIP: 0010:write_comp_data+0x10/0x90 kernel/kcov.c:245
Code: 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 8b 05 39 be 05 12 49 89 f8 49 89 f1 49 89 d2 <65> 48 8b 3d 10 be 05 12 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00
RSP: 0000:ffffc90007756e20 EFLAGS: 00000206
RAX: 0000000080000000 RBX: ffff88802828b780 RCX: ffffffff84d3b6a8
RDX: 0000000000000800 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000900 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000800 R11: 0000000000000000 R12: ffff88802828b79c
R13: 000000845bd5fc31 R14: 0000000000000800 R15: ffffc90007757230
__blk_mq_end_request_acct+0x58/0x450 block/blk-mq.c:1152
__blk_mq_end_request block/blk-mq.c:1162 [inline]
blk_mq_end_request+0x2fb/0x420 block/blk-mq.c:1180
blk_mq_complete_request block/blk-mq.c:1356 [inline]
blk_mq_complete_request+0x8b/0xb0 block/blk-mq.c:1353
nullb_complete_cmd drivers/block/null_blk/main.c:1412 [inline]
null_handle_cmd drivers/block/null_blk/main.c:1464 [inline]
null_queue_rq+0xb48/0xfb0 drivers/block/null_blk/main.c:1703
null_queue_rqs+0xe9/0x2f0 drivers/block/null_blk/main.c:1717
__blk_mq_flush_list block/blk-mq.c:2858 [inline]
__blk_mq_flush_list+0x9a/0xc0 block/blk-mq.c:2854
blk_mq_dispatch_queue_requests+0x184/0x7c0 block/blk-mq.c:2903
blk_mq_flush_plug_list+0x1f2/0x600 block/blk-mq.c:2991
__blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1230
blk_finish_plug block/blk-core.c:1257 [inline]
__submit_bio+0x584/0x6c0 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x562/0xc10 block/blk-core.c:753
submit_bio_noacct+0xd17/0x2010 block/blk-core.c:884
submit_bio_wait+0x110/0x250 block/bio.c:1508
__blkdev_direct_IO_simple+0x49c/0x890 block/fops.c:98
blkdev_direct_IO+0xc76/0x1fb0 block/fops.c:430
blkdev_direct_write block/fops.c:722 [inline]
blkdev_write_iter+0x703/0xd70 block/fops.c:790
iter_file_splice_write+0x830/0x10a0 fs/splice.c:736
do_splice_from fs/splice.c:936 [inline]
direct_splice_actor+0x192/0x6c0 fs/splice.c:1159
splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103
do_splice_direct_actor fs/splice.c:1202 [inline]
do_splice_direct+0x174/0x240 fs/splice.c:1228
do_sendfile+0xadc/0xe20 fs/read_write.c:1372
__do_sys_sendfile64 fs/read_write.c:1433 [inline]
__se_sys_sendfile64 fs/read_write.c:1419 [inline]
__x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1419
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffbc2d9c819
RSP: 002b:00007ffbc3c33028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007ffbc3016090 RCX: 00007ffbc2d9c819
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000003
RBP: 00007ffbc2e32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000400000000006 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffbc3016128 R14: 00007ffbc3016090 R15: 00007ffe676948e8
task:syz.4.1919 state:R running task stack:23840 pid:15156 tgid:15156 ppid:11280 task_flags:0x40064c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
preempt_schedule_notrace+0x5f/0xd0 kernel/sched/core.c:7188
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x8e/0xc0 kernel/rcu/tree.c:753
rcu_read_lock include/linux/rcupdate.h:851 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0x6fa/0x1ea0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:165
__reset_page_owner+0x84/0x190 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1433 [inline]
free_unref_folios+0xaea/0x1790 mm/page_alloc.c:3040
folios_put_refs+0x53c/0x840 mm/swap.c:1002
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1149
shmem_truncate_range mm/shmem.c:1277 [inline]
shmem_evict_inode+0x39e/0xbd0 mm/shmem.c:1407
evict+0x3c2/0xad0 fs/inode.c:846
iput_final fs/inode.c:1966 [inline]
iput.part.0+0x605/0xf50 fs/inode.c:2015
iput+0x35/0x40 fs/inode.c:1981
dentry_unlink_inode+0x2a1/0x490 fs/dcache.c:467
__dentry_kill+0x1d0/0x600 fs/dcache.c:670
finish_dput+0x76/0x480 fs/dcache.c:879
dput.part.0+0x456/0x570 fs/dcache.c:928
dput+0x1f/0x30 fs/dcache.c:920
__fput+0x519/0xb40 fs/file_table.c:477
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x8b8/0x2b60 kernel/exit.c:976
do_group_exit+0xd5/0x2a0 kernel/exit.c:1118
get_signal+0x1ec7/0x21e0 kernel/signal.c:3034
arch_do_signal_or_restart+0x91/0x770 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline]
irqentry_exit+0x1f8/0x670 kernel/entry/common.c:219
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x21000
RSP: 002b:000000000000000f EFLAGS: 00010257
RAX: 0000000000000003 RBX: 00007f2605015fa0 RCX: 00007f2604d9c819
RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000020003b46
RBP: 00007f2604e32c91 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2605016038 R14: 00007f2605015fa0 R15: 00007ffc8441a5a8
task:syz.4.1919 state:R running task stack:23688 pid:15162 tgid:15162 ppid:11280 task_flags:0x40064c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7238
irqentry_exit+0x17b/0x670 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x5e/0x380 kernel/locking/lockdep.c:5872
Code: 05 3b 8d 29 12 83 f8 07 0f 87 f0 00 00 00 48 0f a3 05 06 89 f5 0e 0f 82 c2 02 00 00 8b 35 ce bc f5 0e 85 f6 0f 85 dd 00 00 00 <48> 8b 44 24 30 65 48 2b 05 dd 8c 29 12 0f 85 02 03 00 00 48 83 c4
RSP: 0018:ffffc9000e356e78 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8de5cea9 RDI: ffffffff8c1b1da0
RBP: ffffffff8e7e7760 R08: 0000000086db7919 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
__unwind_start+0x3d1/0x7f0 arch/x86/kernel/unwind_orc.c:773
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0xf0 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:165
__reset_page_owner+0x84/0x190 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1433 [inline]
free_unref_folios+0xaea/0x1790 mm/page_alloc.c:3040
folios_put_refs+0x53c/0x840 mm/swap.c:1002
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1149
shmem_truncate_range mm/shmem.c:1277 [inline]
shmem_evict_inode+0x39e/0xbd0 mm/shmem.c:1407
evict+0x3c2/0xad0 fs/inode.c:846
iput_final fs/inode.c:1966 [inline]
iput.part.0+0x605/0xf50 fs/inode.c:2015
iput+0x35/0x40 fs/inode.c:1981
dentry_unlink_inode+0x2a1/0x490 fs/dcache.c:467
__dentry_kill+0x1d0/0x600 fs/dcache.c:670
finish_dput+0x76/0x480 fs/dcache.c:879
dput.part.0+0x456/0x570 fs/dcache.c:928
dput+0x1f/0x30 fs/dcache.c:920
__fput+0x519/0xb40 fs/file_table.c:477
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x8b8/0x2b60 kernel/exit.c:976
do_group_exit+0xd5/0x2a0 kernel/exit.c:1118
get_signal+0x1ec7/0x21e0 kernel/signal.c:3034
arch_do_signal_or_restart+0x91/0x770 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline]
irqentry_exit+0x1f8/0x670 kernel/entry/common.c:219
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x20fff
RSP: 002b:000000000000000f EFLAGS: 00010206
RAX: 0000000000000000 RBX: 00007f2605015fa0 RCX: 00007f2604d9c819
RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000020003b46
RBP: 00007f2604e32c91 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2605016038 R14: 00007f2605015fa0 R15: 00007ffc8441a5a8
task:syz.0.1952 state:R running task stack:23512 pid:15304 tgid:15304 ppid:5836 task_flags:0x400640 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7238
irqentry_exit+0x17b/0x670 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:396 [inline]
RIP: 0010:__rcu_read_unlock+0x32/0x5e0 kernel/rcu/tree_plugin.h:435
Code: 41 55 41 54 55 53 65 48 8b 1d 72 23 20 12 48 8d bb c4 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 0a 02 00 00 83
RSP: 0000:ffffc900077c60a8 EFLAGS: 00000a03
RAX: dffffc0000000000 RBX: ffff88802928db80 RCX: ffffc900077c60a4
RDX: 0000000000000000 RSI: ffffffff8de5cea9 RDI: ffff88802928e044
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000015862 R12: ffffc900077c61a0
R13: ffffc900077c6150 R14: ffffc900077c6cf0 R15: ffffc900077c6184
rcu_read_unlock include/linux/rcupdate.h:883 [inline]
class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0x3c8/0x1ea0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:165
__set_page_owner+0x8c/0x540 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
prep_new_page mm/page_alloc.c:1897 [inline]
get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962
__alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2490
folio_alloc_mpol_noprof+0x36/0x340 mm/mempolicy.c:2509
shmem_alloc_folio+0x135/0x160 mm/shmem.c:1930
shmem_alloc_and_add_folio+0x371/0xd40 mm/shmem.c:1972
shmem_get_folio_gfp+0x6ab/0x1900 mm/shmem.c:2567
shmem_fault+0x1f9/0xa20 mm/shmem.c:2768
__do_fault+0x10d/0x550 mm/memory.c:5364
do_read_fault mm/memory.c:5799 [inline]
do_fault+0xabb/0x18e0 mm/memory.c:5933
do_pte_missing mm/memory.c:4477 [inline]
handle_pte_fault mm/memory.c:6317 [inline]
__handle_mm_fault+0x1815/0x2b60 mm/memory.c:6455
handle_mm_fault+0x36d/0xa20 mm/memory.c:6624
faultin_page mm/gup.c:1126 [inline]
__get_user_pages+0xf9c/0x34d0 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/0xb50 fs/coredump.c:1367
elf_core_dump+0x2d5f/0x3d10 fs/binfmt_elf.c:2110
coredump_write fs/coredump.c:1050 [inline]
do_coredump fs/coredump.c:1127 [inline]
vfs_coredump+0x27bc/0x5570 fs/coredump.c:1201
get_signal+0x1f2a/0x21e0 kernel/signal.c:3019
arch_do_signal_or_restart+0x91/0x770 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline]
irqentry_exit+0x1f8/0x670 kernel/entry/common.c:219
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x401000
RSP: 002b:000000000000000a EFLAGS: 00010206
RAX: 0000000000000000 RBX: 00007f7a23216270 RCX: 00007f7a22f9c819
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000020003b46
RBP: 00007f7a23032c91 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7a23216308 R14: 00007f7a23216270 R15: 00007ffe886d8e18
rcu: rcu_preempt kthread starved for 10154 jiffies! g91425 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:27832 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 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:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: a8 84 02 c3 cc cc cc cc 0f 1f 00 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 43 00 1d 00 fb f4 fc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df0 EFLAGS: 00000242
RAX: 000000000014dcd3 RBX: ffff88801e698000 RCX: ffffffff8b8e8c75
RDX: 0000000000000000 RSI: ffffffff8de82fd4 RDI: ffffffff8c1b1da0
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170a679d
R10: ffff8880b8533ceb R11: 0000000000000000 R12: 0000000000000001
R13: ffffed1003cd3000 R14: 0000000000000001 R15: ffffffff90d9fc10
FS: 0000000000000000(0000) GS:ffff888124440000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564a9bf226d0 CR3: 000000000e598000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x464/0x590 kernel/sched/idle.c:352
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148