Message-ID: <66ed061d.050a0220.29194.0053.GAE@google.com>
Date: Thu, 19 Sep 2024 22:20:29 -0700
From: syzbot <syzbot+5fca234bd7eb378ff78e@...kaller.appspotmail.com>
To: asml.silence@...il.com, axboe@...nel.dk, io-uring@...r.kernel.org, 
	linux-kernel@...r.kernel.org, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [io-uring?] INFO: rcu detected stall in sys_io_uring_enter (2)

Hello,

syzbot found the following issue on:

HEAD commit:    98f7e32f20d2 Linux 6.11
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17271c07980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c78874575ba70f27
dashboard link: https://syzkaller.appspot.com/bug?extid=5fca234bd7eb378ff78e
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/20d79fec7eb2/disk-98f7e32f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/57606ddb0989/vmlinux-98f7e32f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/901e6ba22e57/bzImage-98f7e32f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5fca234bd7eb378ff78e@...kaller.appspotmail.com

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=11bc/1/0x4000000000000000 softirq=116660/116660 fqs=17
rcu: 	(detected by 0, t=10502 jiffies, g=200145, q=315 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6917 Comm: syz.2.16175 Not tainted 6.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:match_held_lock+0x0/0xb0 kernel/locking/lockdep.c:5204
Code: 08 75 11 48 89 d8 48 83 c4 10 5b 41 5e 41 5f c3 cc cc cc cc e8 11 f9 ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 53 bd 01 00 00 00 48 39 77 10 74 67 48 89 fb 81 7f 20 00 00 20
RSP: 0018:ffffc90000a18d10 EFLAGS: 00000083
RAX: 0000000000000002 RBX: ffff888057310b08 RCX: ffff888057310000
RDX: ffff888057310000 RSI: ffff8880b892c898 RDI: ffff888057310b08
RBP: 0000000000000001 R08: ffffffff8180cfbe R09: 0000000000000000
R10: ffff88803641a340 R11: ffffed1006c8346b R12: 0000000000000046
R13: ffff888057310000 R14: 00000000ffffffff R15: ffff8880b892c898
FS:  00007f183bd6c6c0(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7205d61f98 CR3: 000000001bb10000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __lock_is_held kernel/locking/lockdep.c:5500 [inline]
 lock_is_held_type+0xa9/0x190 kernel/locking/lockdep.c:5831
 lock_is_held include/linux/lockdep.h:249 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1655 [inline]
 __hrtimer_run_queues+0x2d9/0xd50 kernel/time/hrtimer.c:1753
 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1815
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
 __sysvec_apic_timer_interrupt+0x110/0x3f0 arch/x86/kernel/apic/apic.c:1049
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5763
Code: 2b 00 74 08 4c 89 f7 e8 ea e1 87 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc9000c5c79a0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff920018b8f40 RCX: 2e46bf6ba4daf100
RDX: dffffc0000000000 RSI: ffffffff8beae6c0 RDI: ffffffff8c3fbac0
RBP: ffffc9000c5c7ae8 R08: ffffffff93fa6967 R09: 1ffffffff27f4d2c
R10: dffffc0000000000 R11: fffffbfff27f4d2d R12: 1ffff920018b8f3c
R13: dffffc0000000000 R14: ffffc9000c5c7a00 R15: 0000000000000246
 __mutex_lock_common kernel/locking/mutex.c:608 [inline]
 __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
 io_cqring_do_overflow_flush io_uring/io_uring.c:644 [inline]
 io_cqring_wait io_uring/io_uring.c:2486 [inline]
 __do_sys_io_uring_enter io_uring/io_uring.c:3255 [inline]
 __se_sys_io_uring_enter+0x1c2a/0x2670 io_uring/io_uring.c:3147
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f183af7def9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f183bd6c038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007f183b135f80 RCX: 00007f183af7def9
RDX: 0000000000400000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f183aff0b76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f183b135f80 R15: 00007ffdf58fafa8
 </TASK>
rcu: rcu_preempt kthread starved for 10467 jiffies! g200145 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:25584 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 8860 Comm: syz.4.17008 Not tainted 6.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:csd_lock_wait kernel/smp.c:312 [inline]
RIP: 0010:smp_call_function_many_cond+0x1860/0x29d0 kernel/smp.c:856
Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 39 18 0c 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 e4 13 0c 00 eb 38 f3 90 <42> 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 c8 13
RSP: 0018:ffffc9000387f400 EFLAGS: 00000246
RAX: ffffffff81877898 RBX: 1ffff110171288e9 RCX: 0000000000040000
RDX: ffffc9000ebfe000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffffc9000387f5e0 R08: ffffffff81877867 R09: 1ffffffff27f4d08
R10: dffffc0000000000 R11: fffffbfff27f4d09 R12: dffffc0000000000
R13: ffff8880b8944748 R14: ffff8880b883fb00 R15: 0000000000000001
FS:  00007f7205d626c0(0000) GS:ffff8880b8800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1e72c656c0 CR3: 000000007b528000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2085 [inline]
 text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2295
 text_poke_bp+0xb0/0x100 arch/x86/kernel/alternative.c:2522
 __static_call_transform+0x51a/0x810 arch/x86/kernel/static_call.c:111
 arch_static_call_transform+0x141/0x380 arch/x86/kernel/static_call.c:163
 __static_call_update+0xd8/0x5e0 kernel/static_call_inline.c:147
 tracepoint_update_call kernel/tracepoint.c:317 [inline]
 tracepoint_add_func+0x918/0x9e0 kernel/tracepoint.c:358
 tracepoint_probe_register_prio_may_exist+0x122/0x190 kernel/tracepoint.c:482
 bpf_raw_tp_link_attach+0x48b/0x6e0 kernel/bpf/syscall.c:3896
 bpf_raw_tracepoint_open+0x1c2/0x240 kernel/bpf/syscall.c:3927
 __sys_bpf+0x3c0/0x810 kernel/bpf/syscall.c:5752
 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5815 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5815
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7204f7def9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7205d62038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f7205135f80 RCX: 00007f7204f7def9
RDX: 0000000000000010 RSI: 0000000020000200 RDI: 0000000000000011
RBP: 00007f7204ff0b76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f7205135f80 R15: 00007ffda5863568
 </TASK>


---
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