syzbot

 sign-in | mailing list | source | docs
🐞 Open [1608]
≡ Subsystems
🐞 Fixed [6143]
🐞 Invalid [15361]
⬇ Missing Backports [171]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
💬 Send us feedback

INFO: rcu detected stall in loop_control_ioctl

Status: auto-obsoleted due to no activity on 2023/11/11 10:36
Subsystems: kernfs
[Documentation on labels]
First crash: 596d, last: 596d
▶ ▼ Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 BUG: soft lockup in loop_control_ioctl 3 288d 292d 0/2 auto-obsoleted due to no activity on 2024/09/14 23:18
upstream BUG: sleeping function called from invalid context in blk_release_queue C inconclusive 25247 1089d 1106d 0/28 closed as dup on 2022/04/02 11:06

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10500 ticks this GP) idle=2024/1/0x4000000000000000 softirq=16485/16485 fqs=0
rcu: 	(t=10500 jiffies g=16889 q=550 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g16889 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=12128
rcu: rcu_preempt kthread starved for 10500 jiffies! g16889 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28672 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0xee1/0x59f0 kernel/sched/core.c:6710
 schedule+0xe7/0x1b0 kernel/sched/core.c:6786
 schedule_timeout+0x157/0x2c0 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x1ec/0xa50 kernel/rcu/tree.c:1609
 rcu_gp_kthread+0x249/0x380 kernel/rcu/tree.c:1808
 kthread+0x33a/0x430 kernel/kthread.c:389
 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 7695 Comm: syz-executor.2 Not tainted 6.5.0-rc5-syzkaller-00362-ga785fd28d31f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:207
Code: b0 01 00 00 e8 b0 ff ff ff 31 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 65 8b 05 dd b0 7d 7e 89 c1 48 8b 34 24 <81> e1 00 01 00 00 65 48 8b 14 25 80 b9 03 00 a9 00 01 ff 00 74 0e
RSP: 0018:ffffc900001e0d58 EFLAGS: 00000293
RAX: 0000000000000104 RBX: ffff888079957394 RCX: 0000000000000104
RDX: ffff888078de8000 RSI: ffffffff8859597d RDI: 0000000000000004
RBP: 000000000000000a R08: 0000000000000004 R09: 000000000000000a
R10: 000000000000000c R11: ffffc900001e0ff8 R12: 0000000000000008
R13: ffff888023568b60 R14: 000000000000000c R15: 0000000000000001
FS:  00007fb9181dd6c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f75b0ea5000 CR3: 000000002279d000 CR4: 0000000000350ee0
Call Trace:
 <IRQ>
 taprio_next_tc_txq net/sched/sch_taprio.c:775 [inline]
 taprio_dequeue_tc_priority+0x33d/0x4b0 net/sched/sch_taprio.c:801
 taprio_dequeue+0x12e/0x5f0 net/sched/sch_taprio.c:868
 dequeue_skb net/sched/sch_generic.c:292 [inline]
 qdisc_restart net/sched/sch_generic.c:397 [inline]
 __qdisc_run+0x1c4/0x19d0 net/sched/sch_generic.c:415
 qdisc_run include/net/pkt_sched.h:125 [inline]
 qdisc_run include/net/pkt_sched.h:122 [inline]
 net_tx_action+0x71e/0xc80 net/core/dev.c:5049
 __do_softirq+0x218/0x965 kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu kernel/softirq.c:632 [inline]
 irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1109
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x70 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 f6 4d 31 f7 48 89 df e8 ce cc 31 f7 f7 c5 00 02 00 00 75 1f 9c 58 f6 c4 02 75 2f <bf> 01 00 00 00 e8 75 6f 23 f7 65 8b 05 46 fd cd 75 85 c0 74 12 5b
RSP: 0018:ffffc9001560fa78 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffff88801e80e328 RCX: 1ffffffff230e86a
RDX: 0000000000000000 RSI: ffffffff8a6c80a0 RDI: ffffffff8ac811c0
RBP: 0000000000000283 R08: 0000000000000001 R09: fffffbfff2309ddb
R10: ffffffff9184eedf R11: 0000000000000000 R12: 0000000000000283
R13: ffff88801e80d954 R14: ffff88801e80e328 R15: ffff8880b983c3c0
 try_to_wake_up+0x7d1/0x15a0 kernel/sched/core.c:4347
 wake_up_process kernel/sched/core.c:4479 [inline]
 wake_up_q+0x82/0xf0 kernel/sched/core.c:1029
 rwsem_wake.isra.0+0xc6/0x110 kernel/locking/rwsem.c:1214
 __up_write kernel/locking/rwsem.c:1376 [inline]
 up_write+0x1f9/0x510 kernel/locking/rwsem.c:1626
 kernfs_remove_by_name_ns+0xc4/0x120 fs/kernfs/dir.c:1673
 kernfs_remove_by_name include/linux/kernfs.h:618 [inline]
 remove_files+0x96/0x1c0 fs/sysfs/group.c:28
 sysfs_remove_group+0x8b/0x170 fs/sysfs/group.c:292
 sysfs_remove_groups fs/sysfs/group.c:316 [inline]
 sysfs_remove_groups+0x60/0xa0 fs/sysfs/group.c:308
 __kobject_del+0x89/0x1f0 lib/kobject.c:588
 kobject_del lib/kobject.c:620 [inline]
 kobject_del+0x3f/0x60 lib/kobject.c:612
 blk_unregister_queue+0x165/0x2e0 block/blk-sysfs.c:913
 del_gendisk+0x325/0xac0 block/genhd.c:675
 loop_remove drivers/block/loop.c:2115 [inline]
 loop_control_remove drivers/block/loop.c:2174 [inline]
 loop_control_ioctl+0x4f4/0x630 drivers/block/loop.c:2212
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fb91967cae9
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:00007fb9181dd0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb91979c120 RCX: 00007fb91967cae9
RDX: 000000000000000b RSI: 0000000000004c81 RDI: 0000000000000008
RBP: 00007fb9196c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fb91979c120 R15: 00007ffd2e5e3d38
 </TASK>
CPU: 1 PID: 7695 Comm: syz-executor.2 Not tainted 6.5.0-rc5-syzkaller-00362-ga785fd28d31f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:207
Code: b0 01 00 00 e8 b0 ff ff ff 31 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 65 8b 05 dd b0 7d 7e 89 c1 48 8b 34 24 <81> e1 00 01 00 00 65 48 8b 14 25 80 b9 03 00 a9 00 01 ff 00 74 0e
RSP: 0018:ffffc900001e0d58 EFLAGS: 00000293
RAX: 0000000000000104 RBX: ffff888079957394 RCX: 0000000000000104
RDX: ffff888078de8000 RSI: ffffffff8859597d RDI: 0000000000000004
RBP: 000000000000000a R08: 0000000000000004 R09: 000000000000000a
R10: 000000000000000c R11: ffffc900001e0ff8 R12: 0000000000000008
R13: ffff888023568b60 R14: 000000000000000c R15: 0000000000000001
FS:  00007fb9181dd6c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f75b0ea5000 CR3: 000000002279d000 CR4: 0000000000350ee0
Call Trace:
 <IRQ>
 taprio_next_tc_txq net/sched/sch_taprio.c:775 [inline]
 taprio_dequeue_tc_priority+0x33d/0x4b0 net/sched/sch_taprio.c:801
 taprio_dequeue+0x12e/0x5f0 net/sched/sch_taprio.c:868
 dequeue_skb net/sched/sch_generic.c:292 [inline]
 qdisc_restart net/sched/sch_generic.c:397 [inline]
 __qdisc_run+0x1c4/0x19d0 net/sched/sch_generic.c:415
 qdisc_run include/net/pkt_sched.h:125 [inline]
 qdisc_run include/net/pkt_sched.h:122 [inline]
 net_tx_action+0x71e/0xc80 net/core/dev.c:5049
 __do_softirq+0x218/0x965 kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu kernel/softirq.c:632 [inline]
 irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1109
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x70 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 f6 4d 31 f7 48 89 df e8 ce cc 31 f7 f7 c5 00 02 00 00 75 1f 9c 58 f6 c4 02 75 2f <bf> 01 00 00 00 e8 75 6f 23 f7 65 8b 05 46 fd cd 75 85 c0 74 12 5b
RSP: 0018:ffffc9001560fa78 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffff88801e80e328 RCX: 1ffffffff230e86a
RDX: 0000000000000000 RSI: ffffffff8a6c80a0 RDI: ffffffff8ac811c0
RBP: 0000000000000283 R08: 0000000000000001 R09: fffffbfff2309ddb
R10: ffffffff9184eedf R11: 0000000000000000 R12: 0000000000000283
R13: ffff88801e80d954 R14: ffff88801e80e328 R15: ffff8880b983c3c0
 try_to_wake_up+0x7d1/0x15a0 kernel/sched/core.c:4347
 wake_up_process kernel/sched/core.c:4479 [inline]
 wake_up_q+0x82/0xf0 kernel/sched/core.c:1029
 rwsem_wake.isra.0+0xc6/0x110 kernel/locking/rwsem.c:1214
 __up_write kernel/locking/rwsem.c:1376 [inline]
 up_write+0x1f9/0x510 kernel/locking/rwsem.c:1626
 kernfs_remove_by_name_ns+0xc4/0x120 fs/kernfs/dir.c:1673
 kernfs_remove_by_name include/linux/kernfs.h:618 [inline]
 remove_files+0x96/0x1c0 fs/sysfs/group.c:28
 sysfs_remove_group+0x8b/0x170 fs/sysfs/group.c:292
 sysfs_remove_groups fs/sysfs/group.c:316 [inline]
 sysfs_remove_groups+0x60/0xa0 fs/sysfs/group.c:308
 __kobject_del+0x89/0x1f0 lib/kobject.c:588
 kobject_del lib/kobject.c:620 [inline]
 kobject_del+0x3f/0x60 lib/kobject.c:612
 blk_unregister_queue+0x165/0x2e0 block/blk-sysfs.c:913
 del_gendisk+0x325/0xac0 block/genhd.c:675
 loop_remove drivers/block/loop.c:2115 [inline]
 loop_control_remove drivers/block/loop.c:2174 [inline]
 loop_control_ioctl+0x4f4/0x630 drivers/block/loop.c:2212
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fb91967cae9
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:00007fb9181dd0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb91979c120 RCX: 00007fb91967cae9
RDX: 000000000000000b RSI: 0000000000004c81 RDI: 0000000000000008
RBP: 00007fb9196c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fb91979c120 R15: 00007ffd2e5e3d38
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/08/13 10:31 upstream a785fd28d31f 39990d51 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in loop_control_ioctl
* Struck through repros no longer work on HEAD.