rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7965/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=23221, q=619 ncpus=2)
task:syz.4.563 state:R running task stack:22472 pid:7965 ppid:7742 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:119 [inline]
RIP: 0010:lock_is_held_type+0x39/0x190 kernel/locking/lockdep.c:5818
Code: 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 bd ff ff ff ff 83 3d f0 3c 03 04 00 0f 84 03 01 00 00 65 8b 05 ef 2b 7a 75 <85> c0 0f 85 f4 00 00 00 65 48 8b 1d f7 57 7b 75 83 bb dc 0a 00 00
RSP: 0018:ffffc900036f6db8 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffc900036f6ee0 RCX: 727f87ef0b27ab00
RDX: ffff8880276fda00 RSI: 00000000ffffffff RDI: ffffffff8d132160
RBP: 00000000ffffffff R08: dffffc0000000000 R09: 1ffffffff2239aa0
R10: dffffc0000000000 R11: fffffbfff2239aa1 R12: ffff88805c502ec2
R13: ffff88802d139160 R14: 0000000000000017 R15: ffff88805f465340
xa_entry include/linux/xarray.h:1216 [inline]
xas_descend+0x129/0x490 lib/xarray.c:206
xas_load+0xbe/0x140 lib/xarray.c:244
filemap_get_entry+0x182/0x3f0 mm/filemap.c:1852
shmem_get_folio_gfp+0x2a5/0x2aa0 mm/shmem.c:1975
shmem_get_folio mm/shmem.c:2164 [inline]
shmem_write_begin+0xf2/0x420 mm/shmem.c:2706
generic_perform_write+0x2fe/0x5c0 mm/filemap.c:4036
shmem_file_write_iter+0xfb/0x120 mm/shmem.c:2883
__kernel_write_iter+0x28c/0x690 fs/read_write.c:517
dump_emit_page fs/coredump.c:957 [inline]
dump_user_range+0x420/0x860 fs/coredump.c:984
elf_core_dump+0x31d0/0x3770 fs/binfmt_elf.c:2184
do_coredump+0x17cc/0x24d0 fs/coredump.c:833
get_signal+0x1133/0x13f0 kernel/signal.c:2888
arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
irqentry_exit_to_user_mode+0x9/0x30 kernel/entry/common.c:315
exc_general_protection+0x168/0x1f0 arch/x86/kernel/traps.c:745
asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:602
RIP: 0033:0x7f8d7159ce61
RSP: 002b:0000200000000100 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f8d71816180 RCX: 00007f8d7159ce59
RDX: 0000200000000240 RSI: 0000200000000100 RDI: 0000000008000400
RBP: 00007f8d71632d6f R08: 0000200000001980 R09: 0000200000001980
R10: 00002000000002c0 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f8d71816218 R14: 00007f8d71816180 R15: 00007ffe64e26eb8
rcu: rcu_preempt kthread starved for 10539 jiffies! g23221 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:27656 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 7971 Comm: syz.4.565 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x2e/0x90 kernel/kcov.c:313
Code: 48 8b 04 24 65 48 8b 15 f0 86 7c 7e 65 8b 0d f1 86 7c 7e 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 5b 83 ba 1c 16 00 00 00 <74> 52 8b 8a f8 15 00 00 83 f9 03 75 47 48 8b 8a 00 16 00 00 44 8b
RSP: 0018:ffffc900001f0478 EFLAGS: 00000246
RAX: ffffffff813b3657 RBX: ffffc900001f04a8 RCX: 0000000000000100
RDX: ffff8880187fbc00 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000002 R08: ffff8880187fbc00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000100 R12: ffffffff8902acb3
R13: ffffc900001f08b8 R14: dffffc0000000000 R15: ffffc900001f04a8
FS: 00007f8d723f86c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8d723d7d58 CR3: 0000000068c99000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000608
Call Trace:
unwind_done arch/x86/include/asm/unwind.h:50 [inline]
unwind_get_return_address+0x37/0xc0 arch/x86/kernel/unwind_orc.c:366
arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
__kmem_cache_free+0xba/0x1e0 mm/slub.c:3843
skb_kfree_head net/core/skbuff.c:946 [inline]
skb_free_head net/core/skbuff.c:958 [inline]
skb_release_data+0x5dc/0x7b0 net/core/skbuff.c:988
skb_release_all net/core/skbuff.c:1054 [inline]
__kfree_skb+0x57/0x70 net/core/skbuff.c:1068
tcp_write_queue_purge+0x143/0x2f0 net/ipv4/tcp.c:3007
tcp_done_with_error+0x43/0xc0 net/ipv4/tcp_input.c:4446
tcp_write_err net/ipv4/tcp_timer.c:72 [inline]
tcp_write_timeout net/ipv4/tcp_timer.c:281 [inline]
tcp_retransmit_timer+0x1728/0x3020 net/ipv4/tcp_timer.c:576
tcp_write_timer+0x12a/0x280 net/ipv4/tcp_timer.c:709
call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x542/0x800 kernel/time/timer.c:2023
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:80 [inline]
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:102 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
RIP: 0010:unwind_next_frame+0x4a3/0x2970 arch/x86/kernel/unwind_orc.c:494
Code: 74 24 48 48 89 d8 4c 29 e0 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 4d 8d 3c 44 4c 89 f8 48 c1 e8 03 0f b6 04 10 <84> c0 75 3e 4d 63 2f 4d 01 fd 4c 89 ef 4c 89 f6 e8 28 f1 4b 00 49
RSP: 0018:ffffc900037272b8 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffffffff8f047b28 RCX: 0000000000000007
RDX: dffffc0000000000 RSI: 00000000001b264a RDI: 00000000001b2652
RBP: ffffffff8f047b0c R08: ffffc90003727450 R09: 0000000000000005
R10: 0000000000000004 R11: 0000000000000002 R12: ffffffff8f047b0c
R13: 00000000001b264a R14: ffffffff8a886486 R15: ffffffff8f047b18
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
__call_rcu_common kernel/rcu/tree.c:2721 [inline]
call_rcu+0x153/0x950 kernel/rcu/tree.c:2837
context_switch kernel/sched/core.c:5384 [inline]
__schedule+0x155b/0x45a0 kernel/sched/core.c:6700
preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__mutex_lock+0x99a/0xcc0 kernel/locking/mutex.c:747
Code: 3d 04 f8 f8 f8 f8 43 c6 44 3d 08 f8 48 c7 84 24 80 00 00 00 0e 36 e0 45 4b c7 44 3d 00 00 00 00 00 4b c7 44 3d 08 00 00 00 00 <65> 48 8b 04 25 28 00 00 00 48 3b 84 24 00 01 00 00 0f 85 16 02 00
RSP: 0018:ffffc90003727be0 EFLAGS: 00000286
RAX: 0000000080000000 RBX: ffff8880187fd028 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8b1c9c00 RDI: 00000000ffffffff
RBP: ffffc90003727d30 R08: ffffffff8e8b666f R09: 1ffffffff1d16ccd
R10: dffffc0000000000 R11: fffffbfff1d16cce R12: 0000000000000000
R13: 1ffff920006e4f8c R14: 0000000000000000 R15: dffffc0000000000
__do_sys_perf_event_open kernel/events/core.c:12967 [inline]
__se_sys_perf_event_open+0x18b4/0x1c50 kernel/events/core.c:12609
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8d7159ce59
Code: ff c3 66 2e 0f 1f 84 00 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 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8d723f8028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f8d71815fa0 RCX: 00007f8d7159ce59
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 00002000000012c0
RBP: 00007f8d71632d6f R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8d71816038 R14: 00007f8d71815fa0 R15: 00007ffe64e26eb8