syzbot

 sign-in | mailing list | source | docs
🐞 Open [823]
🐞 Fixed [76]
🐞 Invalid [996]
⬇ Missing Backports [121]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

INFO: rcu detected stall in sys_bpf (2)

Status: upstream: reported on 2024/04/09 19:57
Reported-by: syzbot+4ca114518ed3e3b28ead@syzkaller.appspotmail.com
First crash: 521d, last: 21h13m
▶ ▼ Similar bugs (16)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_bpf (5) bpf 1 C unreliable 56 1330d 1423d 0/29 closed as invalid on 2022/02/08 10:34
upstream INFO: rcu detected stall in sys_bpf (9) net bpf 1 C error 74 233d 473d 0/29 auto-obsoleted due to no activity on 2025/04/03 05:23
upstream INFO: rcu detected stall in sys_bpf (3) bpf 1 4 2075d 2075d 0/29 closed as invalid on 2020/01/09 08:13
linux-5.15 INFO: rcu detected stall in sys_bpf 1 2 646d 688d 0/3 auto-obsoleted due to no activity on 2024/03/16 17:33
upstream INFO: rcu detected stall in sys_bpf bpf net 1 3 2241d 2362d 0/29 auto-closed as invalid on 2019/11/23 00:18
upstream INFO: rcu detected stall in sys_bpf (2) bpf 1 12 2110d 2111d 0/29 closed as invalid on 2019/12/04 14:14
upstream INFO: rcu detected stall in sys_bpf (8) bpf 1 1 664d 664d 0/29 auto-obsoleted due to no activity on 2024/02/17 03:10
linux-6.1 INFO: rcu detected stall in sys_bpf origin:lts-only 1 syz 33 5h27m 511d 0/3 upstream: reported syz repro on 2024/04/20 10:27
linux-4.19 INFO: rcu detected stall in sys_bpf 1 3 2059d 2188d 0/1 auto-closed as invalid on 2020/05/23 14:47
upstream BUG: soft lockup in sys_bpf mm 1 31 15h27m 143d 0/29 upstream: reported on 2025/04/23 05:48
upstream INFO: rcu detected stall in sys_bpf (6) net 1 7 1141d 1291d 0/29 auto-obsoleted due to no activity on 2022/10/28 06:32
upstream INFO: rcu detected stall in sys_bpf (4) bpf net 1 3 2028d 2067d 0/29 auto-closed as invalid on 2020/05/24 13:03
linux-6.6 INFO: rcu detected stall in sys_bpf origin:lts-only 1 C 26 16d 34d 0/2 upstream: reported C repro on 2025/08/10 11:50
android-54 BUG: soft lockup in sys_bpf 1 1 211d 211d 0/2 auto-obsoleted due to no activity on 2025/05/15 12:21
android-5-15 BUG: soft lockup in sys_bpf origin:upstream 1 C error 108 366d 533d 0/2 upstream: reported C repro on 2024/03/29 12:25
android-5-10 BUG: soft lockup in sys_bpf 1 2 446d 450d 0/2 auto-obsoleted due to no activity on 2024/09/22 11:37

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6367/1:b..l
	(detected by 1, t=10502 jiffies, g=16681, q=660)
task:syz.4.592       state:R  running task     stack:24928 pid: 6367 ppid:  4192 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:kasan_quarantine_put+0x84/0x220 mm/kasan/quarantine.c:234
Code: e8 81 ae c1 ff 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 0f 85 83 00 00 00 41 f7 c7 00 02 00 00 74 01 fb 31 c0 <48> 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f c3 48 8d 80 40 62 03 00 45
RSP: 0018:ffffc900034ff660 EFLAGS: 00000206
RAX: 3cf6a3aad83b0201 RBX: ffff88805dcbe800 RCX: 3cf6a3aad83b0200
RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480
RBP: ffffc900034ff6f0 R08: dffffc0000000000 R09: ffffed1017207662
R10: ffffed1017207662 R11: 1ffff11017207661 R12: ffff888016841c80
R13: ffff88805dcbe800 R14: 0000000000073ce8 R15: 0000000000000286
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kfree+0xef/0x2a0 mm/slub.c:4564
 skb_free_head net/core/skbuff.c:655 [inline]
 skb_release_data+0x6fe/0x850 net/core/skbuff.c:677
 skb_release_all net/core/skbuff.c:742 [inline]
 __kfree_skb net/core/skbuff.c:756 [inline]
 kfree_skb_reason+0xaf/0x110 net/core/skbuff.c:776
 __bpf_redirect+0xa8f/0xee0 include/linux/skbuff.h:-1
 ____bpf_clone_redirect net/core/filter.c:2453 [inline]
 bpf_clone_redirect+0x241/0x390 net/core/filter.c:2423
 bpf_prog_e26ebb0c7d00e66b+0x59/0x3b0
 bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 bpf_test_run+0x292/0x7d0 net/bpf/test_run.c:119
 bpf_prog_test_run_skb+0x9cc/0x1180 net/bpf/test_run.c:669
 bpf_prog_test_run+0x31e/0x390 kernel/bpf/syscall.c:3374
 __sys_bpf+0x535/0x670 kernel/bpf/syscall.c:4675
 __do_sys_bpf kernel/bpf/syscall.c:4761 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4759 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4759
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f73935c8ba9
RSP: 002b:00007f7391830038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f739380ffa0 RCX: 00007f73935c8ba9
RDX: 0000000000000050 RSI: 0000200000000600 RDI: 000000000000000a
RBP: 00007f739364be19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7393810038 R14: 00007f739380ffa0 R15: 00007ffd1b767a98
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10497 jiffies! g16681 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=5938
rcu: rcu_preempt kthread starved for 10498 jiffies! g16681 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27456 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6356 Comm: syz.3.591 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:irq_work_single kernel/irq_work.c:152 [inline]
RIP: 0010:irq_work_run_list+0x146/0x330 kernel/irq_work.c:177
Code: 01 00 00 44 8b 3b 48 89 df be 04 00 00 00 e8 91 9b 38 00 43 0f b6 04 2c 84 c0 0f 85 27 01 00 00 45 89 fd 41 83 e5 fe 44 89 2b <f0> 83 44 24 fc 00 44 89 fe 83 e6 08 31 ff e8 17 35 f4 ff 44 89 f8
RSP: 0018:ffffc90000007f00 EFLAGS: 00000006
RAX: 0000000000000000 RBX: ffff8880b903b1f8 RCX: ffffffff8183993f
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff8880b903b1f8
RBP: ffffc90000007fb0 R08: dffffc0000000000 R09: ffffed1017207640
R10: ffffed1017207640 R11: 1ffff1101720763f R12: 1ffff1101720763f
R13: 0000000000000022 R14: ffff8880b903b1f0 R15: 0000000000000023
FS:  000055559228a500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f739180fd58 CR3: 0000000078c8c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 irq_work_run+0x63/0xe0 kernel/irq_work.c:186
 __sysvec_irq_work+0x98/0x240 arch/x86/kernel/irq_work.c:22
 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
 sysvec_irq_work+0x98/0xc0 arch/x86/kernel/irq_work.c:17
 </IRQ>
 <TASK>
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ad 13 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc9000329fcc0 EFLAGS: 00000206
RAX: db94af9685377700 RBX: 1ffff92000653f9c RCX: db94af9685377700
RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480
RBP: ffffc9000329fd88 R08: dffffc0000000000 R09: fffffbfff1ff781a
R10: fffffbfff1ff781a R11: 1ffffffff1ff7819 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8c120ba0
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock+0x85/0x90 include/linux/rcupdate.h:771
 dput+0xc0/0x1a0 fs/dcache.c:886
 __fput+0x5ee/0x930 fs/file_table.c:319
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f6d5dc15ba9
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:00007fffdc947368 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f6d5de5eda0 RCX: 00007f6d5dc15ba9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f6d5de5eda0 R08: 0000000000000000 R09: 00000020dc94765f
R10: 000000000003fc9c R11: 0000000000000246 R12: 0000000000022728
R13: 00007fffdc947460 R14: ffffffffffffffff R15: 00007fffdc947480
 </TASK>

Crashes (42):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/12 22:19 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/09/10 10:42 linux-5.15.y de9476bb4f1b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/09/09 11:16 linux-5.15.y 7a6c2d093c45 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/09/08 17:24 linux-5.15.y 7a6c2d093c45 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/09/07 00:40 linux-5.15.y 7a6c2d093c45 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/09/06 14:09 linux-5.15.y 7a6c2d093c45 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/09/03 21:39 linux-5.15.y 01879f56bdde 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/09/01 21:09 linux-5.15.y 01879f56bdde 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/09/01 07:34 linux-5.15.y 01879f56bdde 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/08/25 22:06 linux-5.15.y c79648372d02 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/08/23 23:07 linux-5.15.y c79648372d02 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/08/22 21:55 linux-5.15.y c79648372d02 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/08/22 01:41 linux-5.15.y c79648372d02 3e79b825 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/08/20 04:29 linux-5.15.y c79648372d02 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/08/19 03:25 linux-5.15.y c79648372d02 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/08/18 17:16 linux-5.15.y c79648372d02 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/08/18 16:14 linux-5.15.y c79648372d02 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/08/18 11:32 linux-5.15.y c79648372d02 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/08/17 03:45 linux-5.15.y c79648372d02 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/08/14 20:19 linux-5.15.y c79648372d02 5d8c2ac2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/08/13 13:14 linux-5.15.y c79648372d02 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/08/13 04:33 linux-5.15.y c79648372d02 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/08/11 09:56 linux-5.15.y c79648372d02 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_bpf
2025/08/02 09:09 linux-5.15.y c79648372d02 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/06/07 12:28 linux-5.15.y 1c700860e8bc 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_bpf
2025/05/15 07:59 linux-5.15.y 3b8db0e4f263 d6b2ee52 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/02/11 22:43 linux-5.15.y c16c81c81336 f2baddf5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2025/01/08 07:49 linux-5.15.y 91786f140358 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2024/10/21 01:03 linux-5.15.y 584a40a22cb9 cd6fc0a3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2024/10/07 23:10 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2024/10/04 09:26 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2024/09/29 02:49 linux-5.15.y 3a5928702e71 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2024/09/11 06:26 linux-5.15.y 14e468424d3e 8ab55d0e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2024/09/03 20:34 linux-5.15.y fa93fa65db6e 326f9c5a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2024/09/01 03:43 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2024/08/17 16:09 linux-5.15.y 7e89efd3ae1c dbc93b08 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2024/08/05 21:48 linux-5.15.y 7e89efd3ae1c e35c337f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_bpf
2024/06/17 17:38 linux-5.15.y 4878aadf2d15 1f11cfd7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_bpf
2024/06/12 09:15 linux-5.15.y c61bd26ae81a 4d75f4f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_bpf
2024/05/28 06:04 linux-5.15.y c61bd26ae81a f550015e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_bpf
2024/05/07 13:28 linux-5.15.y 284087d4f7d5 cb2dcc0e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_bpf
2024/04/09 19:57 linux-5.15.y 9465fef4ae35 171ec371 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_bpf
* Struck through repros no longer work on HEAD.