[v5.15] INFO: rcu detected stall in sys_bpf (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9465fef4ae35 Linux 5.15.153
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14c4a915180000
kernel config: https://syzkaller.appspot.com/x/.config?x=176c746ee3348b33
dashboard link: https://syzkaller.appspot.com/bug?extid=4ca114518ed3e3b28ead
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2962c02652ce/disk-9465fef4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d0f5a1ce082d/vmlinux-9465fef4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/86b5b1eea636/bzImage-9465fef4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4ca114...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8083/1:b..l
(detected by 0, t=10502 jiffies, g=27817, q=85)
task:syz-executor.4 state:R running task stack:25752 pid: 8083 ppid: 3524 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6780
irqentry_exit+0x53/0x80 kernel/entry/common.c:426
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:debug_smp_processor_id+0x0/0x10 lib/smp_processor_id.c:60
Code: 92 8a e8 43 01 00 00 65 c7 05 78 47 e7 75 00 00 00 00 48 c7 c7 80 e5 92 8a e8 2c 01 00 00 65 ff 0d 61 47 e7 75 5b c3 cc cc cc <48> c7 c7 60 8f d8 8a 48 c7 c6 a0 8f d8 8a eb 00 41 57 41 56 41 54
RSP: 0018:ffffc90002de78d8 EFLAGS: 00000246
RAX: ffffffff883de1a9 RBX: ffffc90002de7ae0 RCX: 0000000000040000
RDX: ffffc900060b9000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffffc90002de79d0 R08: ffff88807964c000 R09: ffffed100fba8771
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000008
R13: ffffc900011bc030 R14: 0000607f4600f7e8 R15: dffffc0000000000
____bpf_skb_set_tunnel_key net/core/filter.c:4338 [inline]
bpf_skb_set_tunnel_key+0x95/0x920 net/core/filter.c:4335
bpf_prog_b05a1224bf7419fd+0x3a/0x128
bpf_dispatcher_nop_func include/linux/bpf.h:785 [inline]
__bpf_prog_run include/linux/filter.h:628 [inline]
bpf_prog_run include/linux/filter.h:635 [inline]
bpf_test_run+0x3f4/0x8a0 net/bpf/test_run.c:119
bpf_prog_test_run_skb+0xb41/0x1420 net/bpf/test_run.c:663
bpf_prog_test_run+0x32f/0x3a0 kernel/bpf/syscall.c:3368
__sys_bpf+0x3ac/0x670 kernel/bpf/syscall.c:4669
__do_sys_bpf kernel/bpf/syscall.c:4755 [inline]
__se_sys_bpf kernel/bpf/syscall.c:4753 [inline]
__x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7efebc659e69
RSP: 002b:00007efebabcc0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007efebc787f80 RCX: 00007efebc659e69
RDX: 0000000000000050 RSI: 00000000200002c0 RDI: 000000000000000a
RBP: 00007efebc6a647a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007efebc787f80 R15: 00007ffc29fc9548
</TASK>
rcu: rcu_preempt kthread starved for 10534 jiffies! g27817 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:26936 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
schedule+0x11b/0x1f0 kernel/sched/core.c:6459
schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1884
rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
kthread+0x3f6/0x4f0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8085 Comm: syz-executor.3 Not tainted 5.15.153-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:validate_chain+0x9b/0x5930 kernel/locking/lockdep.c:3744
Code: f1 f1 f1 f1 00 f2 f2 f2 4a 89 04 21 48 b8 f2 f2 f2 00 f2 f2 f2 00 4a 89 44 21 09 48 b8 f2 f2 f2 f2 f2 00 00 00 4a 89 44 21 17 <48> b8 f2 f2 f2 f2 f2 00 f3 f3 4a 89 44 21 23 48 89 8c 24 98 00 00
RSP: 0018:ffffc900035a7620 EFLAGS: 00000806
RAX: 000000f2f2f2f2f2 RBX: ffffffff8f8d92c0 RCX: 1ffff920006b4ee4
RDX: 0000000000000001 RSI: ffff88802328e430 RDI: ffff88802328d940
RBP: ffffc900035a78d0 R08: dffffc0000000000 R09: fffffbfff1f7a01f
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff88802328e428 R14: f68e69aad572a630 R15: ffff88802328e450
FS: 0000555555e6a480(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002006b000 CR3: 000000007aee7000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<TASK>
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__might_fault+0xb4/0x110 mm/memory.c:5324
rseq_get_rseq_cs kernel/rseq.c:131 [inline]
rseq_ip_fixup kernel/rseq.c:244 [inline]
__rseq_handle_notify_resume+0x11b/0x1250 kernel/rseq.c:292
rseq_handle_notify_resume include/linux/sched.h:2204 [inline]
rseq_signal_deliver include/linux/sched.h:2213 [inline]
setup_rt_frame arch/x86/kernel/signal.c:769 [inline]
handle_signal arch/x86/kernel/signal.c:824 [inline]
arch_do_signal_or_restart+0x27d/0x1890 arch/x86/kernel/signal.c:869
handle_signal_work kernel/entry/common.c:148 [inline]
exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:172
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301
do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f894f6bbe69
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff36999828 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 000000000002974b RCX: 00007f894f6bbe69
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f894f7ea12c
RBP: 0000000000000032 R08: 00007f894f7ea12c R09: 00007f894f7ea12c
R10: 00007fff36999960 R11: 0000000000000246 R12: 00007f894f7ea12c
R13: 000000000002977d R14: 00007fff36999980 R15: 00007fff36999960
</TASK>
vkms_vblank_simulate: vblank timer overrun
hrtimer: interrupt took 1027786411 ns


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