syzbot

 sign-in | mailing list | source | docs
🐞 Open [1002] ≡ Subsystems 🐞 Fixed [5245] 🐞 Invalid [12540] ⬇ Missing Backports [83] 📈 Kernel Health 📈 Bug Lifetimes 📈 Fuzzing 📈 Crashes 💬 Send us feedback

INFO: rcu detected stall in sys_unshare (7)

Status: auto-obsoleted due to no activity on 2023/06/03 15:22
Subsystems: bpf net
[Documentation on labels]
First crash: 552d, last: 421d
▶ ▼ Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_unshare (2) kernel 1 1574d 1574d 0/26 closed as invalid on 2020/01/08 05:23
upstream INFO: rcu detected stall in sys_unshare (5) net 1 836d 836d 0/26 closed as invalid on 2022/02/08 10:10
upstream INFO: rcu detected stall in sys_unshare (3) net 1 1060d 1060d 0/26 auto-closed as invalid on 2021/09/03 04:28
upstream INFO: rcu detected stall in sys_unshare (6) kernfs 1 805d 805d 0/26 auto-closed as invalid on 2022/05/15 15:21
upstream INFO: rcu detected stall in sys_unshare (9) bpf C inconclusive 3 57d 171d 0/26 upstream: reported C repro on 2023/11/11 00:17
upstream INFO: rcu detected stall in sys_unshare kernel 3 1609d 1610d 0/26 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in sys_unshare (4) kernel 1 968d 968d 0/26 auto-closed as invalid on 2021/12/03 09:38
linux-6.1 INFO: rcu detected stall in sys_unshare origin:upstream C 1 10d 147d 0/3 upstream: reported C repro on 2023/12/04 08:29

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9104/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=23769, q=1525 ncpus=2)
task:syz-executor.4  state:R  running task     stack:28216 pid:9104  ppid:5123   flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5304 [inline]
 __schedule+0xcce/0x5b20 kernel/sched/core.c:6622
 preempt_schedule_irq+0x52/0x90 kernel/sched/core.c:6934
 irqentry_exit+0x35/0x80 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:lock_acquire+0x227/0x670 kernel/locking/lockdep.c:5637
Code: 33 9c 7e 83 f8 01 0f 85 76 03 00 00 9c 58 f6 c4 02 0f 85 61 03 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
RSP: 0018:ffffc9000b3b7588 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff92001676eb4 RCX: 849d7620d3ce006a
RDX: 1ffff11008280146 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff914deb87
R10: fffffbfff229bd70 R11: 0000000000094001 R12: 0000000000000002
R13: 0000000000000000 R14: ffffffff8c795a00 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:327 [inline]
 rcu_read_lock include/linux/rcupdate.h:773 [inline]
 is_bpf_text_address+0x3a/0x1b0 kernel/bpf/core.c:719
 kernel_text_address kernel/extable.c:125 [inline]
 kernel_text_address+0x3d/0x80 kernel/extable.c:94
 __kernel_text_address+0xd/0x30 kernel/extable.c:79
 unwind_get_return_address arch/x86/kernel/unwind_orc.c:342 [inline]
 unwind_get_return_address+0x55/0xa0 arch/x86/kernel/unwind_orc.c:337
 arch_stack_walk+0x97/0xf0 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x90/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 __kasan_slab_alloc+0x7f/0x90 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:186 [inline]
 slab_post_alloc_hook mm/slab.h:769 [inline]
 slab_alloc_node mm/slub.c:3452 [inline]
 slab_alloc mm/slub.c:3460 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3467 [inline]
 kmem_cache_alloc+0x17c/0x320 mm/slub.c:3476
 kmem_cache_zalloc include/linux/slab.h:710 [inline]
 __proc_create+0x2b3/0x8b0 fs/proc/generic.c:426
 proc_create_reg+0xb6/0x180 fs/proc/generic.c:553
 proc_create_net_data+0x90/0x1b0 fs/proc/proc_net.c:120
 igmp6_proc_init net/ipv6/mcast.c:3096 [inline]
 igmp6_net_init+0x225/0x460 net/ipv6/mcast.c:3151
 ops_init+0xb9/0x6b0 net/core/net_namespace.c:135
 setup_net+0x5d1/0xc50 net/core/net_namespace.c:338
 copy_net_ns+0x4ee/0x8e0 net/core/net_namespace.c:490
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:228
 ksys_unshare+0x449/0x920 kernel/fork.c:3205
 __do_sys_unshare kernel/fork.c:3276 [inline]
 __se_sys_unshare kernel/fork.c:3274 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3274
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f2fe448c0f9
RSP: 002b:00007f2fe5128168 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f2fe45ac050 RCX: 00007f2fe448c0f9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f2fe44e7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2fe46cfb1f R14: 00007f2fe5128300 R15: 0000000000022000
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10495 jiffies! g23769 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=14284
rcu: rcu_preempt kthread starved for 10496 jiffies! g23769 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:28672 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5304 [inline]
 __schedule+0xcce/0x5b20 kernel/sched/core.c:6622
 schedule+0xde/0x1a0 kernel/sched/core.c:6698
 schedule_timeout+0x14e/0x2b0 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1608
 rcu_gp_kthread+0x23a/0x360 kernel/rcu/tree.c:1807
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </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: 9118 Comm: syz-executor.0 Not tainted 6.2.0-syzkaller-13534-gb01fe98d34f3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:178 [inline]
RIP: 0010:kasan_check_range+0x34/0x190 mm/kasan/generic.c:187
Code: 01 00 00 49 89 f9 41 54 44 0f b6 c2 49 01 f1 55 53 0f 82 18 01 00 00 48 b8 ff ff ff ff ff 7f ff ff 48 39 c7 0f 86 05 01 00 00 <49> 83 e9 01 48 89 fd 48 b8 00 00 00 00 00 fc ff df 4d 89 ca 48 c1
RSP: 0018:ffffc900147e79c8 EFLAGS: 00000012
RAX: ffff7fffffffffff RBX: 00000000000001cb RCX: ffffffff8165fc4c
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff914debb8
RBP: ffff88807ae427c2 R08: 0000000000000000 R09: ffffffff914debc0
R10: fffffbfff229bd77 R11: 0000000000000000 R12: ffff88807ae427a0
R13: ffff88807ae41d40 R14: 0000000000000000 R15: 3e5d5aebf11c2df6
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32f2d000 CR3: 00000000274d5000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 hlock_class kernel/locking/lockdep.c:228 [inline]
 lookup_chain_cache_add kernel/locking/lockdep.c:3744 [inline]
 validate_chain kernel/locking/lockdep.c:3800 [inline]
 __lock_acquire+0x18bc/0x5d40 kernel/locking/lockdep.c:5056
 lock_acquire kernel/locking/lockdep.c:5669 [inline]
 lock_acquire+0x1e3/0x670 kernel/locking/lockdep.c:5634
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162
 vga_put+0x3b/0x100 drivers/pci/vgaarb.c:536
 vga_arb_release+0x264/0x500 drivers/pci/vgaarb.c:1463
 __fput+0x27c/0xa90 fs/file_table.c:321
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xad3/0x2a40 kernel/exit.c:869
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1019
 __do_sys_exit_group kernel/exit.c:1030 [inline]
 __se_sys_exit_group kernel/exit.c:1028 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1028
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fbc56c8c0f9
Code: Unable to access opcode bytes at 0x7fbc56c8c0cf.
RSP: 002b:00007fbc5579abb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fbc56c8c0f9
RDX: 00007fbc56cea2ab RSI: 0000000000000000 RDI: 000000000000000b
RBP: 000000000000000b R08: 00007ffcb5a5b080 R09: 0000000000000003
R10: 000000000000019b R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbc56ecfb1f R14: 00007fbc5579b300 R15: 0000000000022000
 </TASK>

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/03/05 15:21 upstream b01fe98d34f3 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in sys_unshare
2023/02/21 17:41 upstream 89f5349e0673 f949448d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: rcu detected stall in sys_unshare
2023/02/19 08:59 upstream 5e725d112e1a bcdf85f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: rcu detected stall in sys_unshare
2023/02/04 02:46 upstream 7b753a909f42 1b2f701a .config console log report info ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_unshare
2023/01/25 09:14 upstream fb6e71db53f3 9dfcf09c .config console log report info ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_unshare
2023/01/16 23:25 upstream 5dc4c995db9e a63719e7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_unshare
2023/01/10 16:25 upstream 40c18f363a08 1dac8c7a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_unshare
2023/01/08 18:21 upstream 9b43a525db12 1dac8c7a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_unshare
2022/12/31 14:42 upstream c8451c141e07 ab32d508 .config console log report info ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_unshare
2022/12/03 18:31 upstream a1e9185d20b5 e080de16 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_unshare
2022/10/25 08:40 upstream a970174d7a10 45645420 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_unshare
2023/03/02 02:52 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 2ebd1fbb946d f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: rcu detected stall in sys_unshare
* Struck through repros no longer work on HEAD.