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INFO: rcu detected stall in ppp_ioctl

Status: auto-obsoleted due to no activity on 2025/01/09 16:14
Reported-by: syzbot+618226cbcdb84c9c406a@syzkaller.appspotmail.com
First crash: 493d, last: 493d
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in ppp_ioctl 1 1 45d 45d 0/3 upstream: reported on 2025/12/23 20:21
upstream INFO: rcu detected stall in ppp_ioctl mm 1 3 451d 466d 0/29 auto-obsoleted due to no activity on 2025/02/10 18:41
linux-6.1 INFO: rcu detected stall in ppp_ioctl (2) 1 1 113d 113d 0/3 auto-obsoleted due to no activity on 2026/01/24 16:32
android-5-15 BUG: soft lockup in ppp_ioctl 1 5 531d 658d 0/2 auto-obsoleted due to no activity on 2024/11/22 22:02

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2799 jiffies s: 5053 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4624 Comm: syz.4.270 Not tainted 6.1.112-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:__lock_acquire+0x1234/0x1f80 kernel/locking/lockdep.c:5046
Code: 0f b6 04 10 84 c0 0f 85 53 0b 00 00 83 3d 73 a5 c8 15 00 0f 84 b1 00 00 00 31 db 48 83 c3 40 48 89 d8 48 c1 e8 03 80 3c 10 00 <74> 08 48 89 df e8 72 95 77 00 48 83 3b 00 0f 84 9a 03 00 00 4c 89
RSP: 0018:ffffc900001dfe40 EFLAGS: 00000046
RAX: 1ffffffff21770ec RBX: ffffffff90bb8760 RCX: ffffffff816a9ba0
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff911dd228
RBP: 3fbde5c2879fe4a6 R08: dffffc0000000000 R09: fffffbfff223ba46
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88805a87c658
R13: ffff88805a87bb80 R14: 0000000000000001 R15: 1ffff1100b50f8da
FS:  00007f330ce596c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f330cdf5f98 CR3: 0000000072004000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 seqcount_lockdep_reader_access+0xf8/0x220 include/linux/seqlock.h:102
 ktime_get+0x31/0x270 kernel/time/timekeeping.c:846
 hrtimer_forward_now include/linux/hrtimer.h:508 [inline]
 perf_swevent_hrtimer+0x43b/0x4f0 kernel/events/core.c:10881
 __run_hrtimer kernel/time/hrtimer.c:1689 [inline]
 __hrtimer_run_queues+0x5a7/0xe50 kernel/time/hrtimer.c:1753
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1815
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x3e/0xb0 arch/x86/kernel/apic/apic.c:1106
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:unwind_next_frame+0x0/0x2220 arch/x86/kernel/unwind_orc.c:423
Code: eb 02 31 c0 5b 41 5e 41 5f c3 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 95 4c 89 f7 e8 fb 7c a5 00 eb 8b 66 0f 1f 84 00 00 00 00 00 <55> 41 57 41 56 41 55 41 54 53 48 81 ec a8 00 00 00 48 89 fb 49 be
RSP: 0018:ffffc900001e0718 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc900001e0720 RCX: ffffffff8fdb3000
RDX: dffffc0000000000 RSI: ffffffff88ac30b3 RDI: ffffc900001e0720
RBP: ffffc900001e07b0 R08: 0000000000000016 R09: ffffc900001e0810
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88805a87bb80
R13: ffffffff81786c50 R14: ffffc900001e0800 R15: 0000000000000000
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1724 [inline]
 slab_free_freelist_hook mm/slub.c:1750 [inline]
 slab_free mm/slub.c:3661 [inline]
 kmem_cache_free+0x292/0x510 mm/slub.c:3683
 ext4_end_bio+0x25c/0x4c0 fs/ext4/page-io.c:365
 req_bio_endio block/blk-mq.c:780 [inline]
 blk_update_request+0x53b/0x1010 block/blk-mq.c:925
 scsi_end_request+0x92/0xa00 drivers/scsi/scsi_lib.c:543
 scsi_io_completion+0x1b9/0x430 drivers/scsi/scsi_lib.c:981
 blk_complete_reqs block/blk-mq.c:1130 [inline]
 blk_done_softirq+0xf8/0x140 block/blk-mq.c:1135
 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571
 __do_softirq kernel/softirq.c:605 [inline]
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:654
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:666
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:preempt_schedule_irq+0xf2/0x1c0 kernel/sched/core.c:6870
Code: 89 f5 49 c1 ed 03 eb 0d 48 f7 03 08 00 00 00 0f 84 97 00 00 00 bf 01 00 00 00 e8 e9 22 af f6 e8 14 1f e2 f6 fb bf 01 00 00 00 <e8> 79 b4 ff ff 43 80 7c 3d 00 00 74 08 4c 89 f7 e8 d9 de 32 f7 48
RSP: 0018:ffffc9000acbf680 EFLAGS: 00000282
RAX: 542926189c927c00 RBX: 1ffff92001597ed8 RCX: ffffffff816af0fa
RDX: dffffc0000000000 RSI: ffffffff8b0c0340 RDI: 0000000000000001
RBP: ffffc9000acbf730 R08: dffffc0000000000 R09: fffffbfff223ba46
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92001597ed0
R13: 1ffff92001597ed4 R14: ffffc9000acbf6a0 R15: dffffc0000000000
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:string+0x0/0x2b0 lib/vsprintf.c:721
Code: ff df e9 42 e9 ff ff e8 3e 87 05 00 44 89 f1 80 e1 07 38 c1 0f 8c c2 f3 ff ff 4c 89 f7 e8 28 0d 41 f7 e9 b5 f3 ff ff 0f 1f 00 <55> 41 57 41 56 41 55 41 54 53 48 83 ec 18 49 89 cf 49 89 d4 48 89
RSP: 0018:ffffc9000acbf7f8 EFLAGS: 00000246
RAX: 1ffff92001597f2c RBX: ffffc9000acbf960 RCX: ffff0a00ffffff04
RDX: ffff888058e60b00 RSI: ffff888074394a1c RDI: ffff88807439422f
RBP: ffffc9000acbf8f0 R08: ffffffff8aa0f284 R09: ffffffff8aa0ea40
R10: 0000000000000012 R11: ffff88805a87bb80 R12: ffff0a00ffffff04
R13: dffffc0000000000 R14: ffffc9000acbf880 R15: ffff888074394a1c
 vsnprintf+0x11a4/0x1c70 lib/vsprintf.c:2805
 add_uevent_var+0x1c0/0x440 lib/kobject_uevent.c:680
 kobject_uevent_env+0x31b/0x8c0 lib/kobject_uevent.c:554
 netdev_queue_add_kobject net/core/net-sysfs.c:1675 [inline]
 netdev_queue_update_kobjects+0x22d/0x480 net/core/net-sysfs.c:1716
 register_queue_kobjects net/core/net-sysfs.c:1777 [inline]
 netdev_register_kobject+0x263/0x310 net/core/net-sysfs.c:2017
 register_netdevice+0x108a/0x1720 net/core/dev.c:10099
 ppp_unit_register drivers/net/ppp/ppp_generic.c:1217 [inline]
 ppp_dev_configure+0x850/0xab0 drivers/net/ppp/ppp_generic.c:1273
 ppp_create_interface drivers/net/ppp/ppp_generic.c:3348 [inline]
 ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1058 [inline]
 ppp_ioctl+0x702/0x1c90 drivers/net/ppp/ppp_generic.c:731
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f330bf7dff9
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:00007f330ce59038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f330c135f80 RCX: 00007f330bf7dff9
RDX: 0000000020001400 RSI: 00000000c004743e RDI: 000000000000000d
RBP: 00007f330bff0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f330c135f80 R15: 00007fff1856f5c8
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/01 16:13 linux-6.1.y aa4cd140bba5 ea2b66a6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in ppp_ioctl
* Struck through repros no longer work on HEAD.