INFO: rcu detected stall in sendfile64

Status: auto-closed as invalid on 2019/10/08 13:45
Reported-by: syzbot+98463ccddbdaa4b23d51@syzkaller.appspotmail.com
First crash: 2662d, last: 2662d
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: rcu detected stall in sendfile64 origin:upstream 1 C 2 23d 45d 0/2 upstream: reported C repro on 2026/06/10 03:23
linux-5.15 INFO: rcu detected stall in sendfile64 (2) origin:upstream 1 C 4 20d 21d 0/3 upstream: reported C repro on 2026/07/04 16:00
linux-5.15 INFO: rcu detected stall in sendfile64 1 1 260d 260d 0/3 auto-obsoleted due to no activity on 2026/02/15 23:07
linux-4.14 INFO: rcu detected stall in sendfile64 (2) 1 3 2180d 2334d 0/1 auto-closed as invalid on 2020/12/03 20:18
upstream INFO: rcu detected stall in sendfile64 prio:high mm 1 40 21d 161d 0/29 upstream: reported on 2026/02/14 22:22

Sample crash report:
net_ratelimit: 25 callbacks suppressed
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
INFO: rcu_sched self-detected stall on CPU
	0-...: (10499 ticks this GP) idle=a6e/140000000000001/0 softirq=223324/223327 fqs=0 
	 (t=10500 jiffies g=49836 c=49835 q=3)
rcu_sched kthread starved for 10500 jiffies! g49836 c49835 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0
rcu_sched       R  running task    29776     9      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2807 [inline]
 __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383
 schedule+0x92/0x1c0 kernel/sched/core.c:3427
 schedule_timeout+0x43e/0xe10 kernel/time/timer.c:1744
 rcu_gp_kthread+0xbf4/0x1ec0 kernel/rcu/tree.c:2255
 kthread+0x31c/0x430 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
NMI backtrace for cpu 0
CPU: 0 PID: 9032 Comm: syz-executor.3 Not tainted 4.14.111 #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x138/0x19c lib/dump_stack.c:53
 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x141/0x189 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:158 [inline]
 rcu_dump_cpu_stacks+0x186/0x1d2 kernel/rcu/tree.c:1396
 print_cpu_stall kernel/rcu/tree.c:1542 [inline]
 check_cpu_stall kernel/rcu/tree.c:1610 [inline]
 __rcu_pending kernel/rcu/tree.c:3390 [inline]
 rcu_pending kernel/rcu/tree.c:3452 [inline]
 rcu_check_callbacks.cold+0x43d/0xd0a kernel/rcu/tree.c:2792
 update_process_times+0x31/0x70 kernel/time/timer.c:1588
 tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:161
 tick_sched_timer+0x43/0x130 kernel/time/tick-sched.c:1219
 __run_hrtimer kernel/time/hrtimer.c:1220 [inline]
 __hrtimer_run_queues+0x273/0xbd0 kernel/time/hrtimer.c:1284
 hrtimer_interrupt+0x1d8/0x5d0 kernel/time/hrtimer.c:1318
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1037 [inline]
 smp_apic_timer_interrupt+0x12c/0x600 arch/x86/kernel/apic/apic.c:1062
 apic_timer_interrupt+0x8e/0xa0 arch/x86/entry/entry_64.S:787
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:778 [inline]
RIP: 0010:lock_acquire+0x1ea/0x430 kernel/locking/lockdep.c:3997
RSP: 0018:ffff88802d5ff8d8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0ee2965 RBX: ffff88807f9022c0 RCX: 0000000037b75585
RDX: dffffc0000000000 RSI: ffff88807f902b68 RDI: 0000000000000282
RBP: ffff88802d5ff920 R08: 0000000000003f71 R09: ffffffff88c97f48
R10: ffff88807f902b68 R11: ffff88807f9022c0 R12: ffffffff877efe60
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 fs_reclaim_acquire.part.0+0x24/0x30 mm/page_alloc.c:3551
 fs_reclaim_acquire+0x14/0x20 mm/page_alloc.c:3552
 slab_pre_alloc_hook mm/slab.h:416 [inline]
 slab_alloc mm/slab.c:3376 [inline]
 __do_kmalloc mm/slab.c:3718 [inline]
 __kmalloc+0x52/0x7a0 mm/slab.c:3729
 kmalloc_array include/linux/slab.h:607 [inline]
 kcalloc include/linux/slab.h:618 [inline]
 iter_file_splice_write+0x141/0xae0 fs/splice.c:692
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x126/0x1a0 fs/splice.c:1018
 splice_direct_to_actor+0x2a1/0x7b0 fs/splice.c:973
 do_splice_direct+0x18d/0x230 fs/splice.c:1061
 do_sendfile+0x4db/0xbd0 fs/read_write.c:1440
 SYSC_sendfile64 fs/read_write.c:1501 [inline]
 SyS_sendfile64+0x102/0x110 fs/read_write.c:1487
 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4582f9
RSP: 002b:00007f9d93eb9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000004582f9
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000004
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 00008000fffffffe R11: 0000000000000246 R12: 00007f9d93eba6d4
R13: 00000000004c5267 R14: 00000000004d93a8 R15: 00000000ffffffff
INFO: rcu_preempt detected stalls on CPUs/tasks:
	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7215
	(detected by 0, t=10545 jiffies, g=86519, c=86518, q=87)
kworker/u4:5    R  running task    25312  7215      2 0x80000000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 context_switch kernel/sched/core.c:2807 [inline]
 __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383
 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:3610
 retint_kernel+0x1b/0x2d
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:778 [inline]
RIP: 0010:lock_acquire+0x1ea/0x430 kernel/locking/lockdep.c:3997
RSP: 0018:ffff88806ecd7c90 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0ee2965 RBX: ffff88806ecce640 RCX: 000000002e890d4b
RDX: dffffc0000000000 RSI: ffff88806eccef10 RDI: 0000000000000282
RBP: ffff88806ecd7cd8 R08: 0000000000000000 R09: ffff88806eccef30
R10: ffff88806eccef10 R11: ffff88806ecce640 R12: ffffffff8778ed60
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002
 rcu_lock_acquire include/linux/rcupdate.h:244 [inline]
 rcu_read_lock include/linux/rcupdate.h:631 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline]
 batadv_nc_worker+0x107/0x6d0 net/batman-adv/network-coding.c:726
 process_one_work+0x868/0x1610 kernel/workqueue.c:2114
 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248
 kthread+0x31c/0x430 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
kworker/u4:5    R  running task    25312  7215      2 0x80000000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 context_switch kernel/sched/core.c:2807 [inline]
 __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383
 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:3610
 retint_kernel+0x1b/0x2d
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:778 [inline]
RIP: 0010:lock_acquire+0x1ea/0x430 kernel/locking/lockdep.c:3997
RSP: 0018:ffff88806ecd7c90 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0ee2965 RBX: ffff88806ecce640 RCX: 000000002e890d4b
RDX: dffffc0000000000 RSI: ffff88806eccef10 RDI: 0000000000000282
RBP: ffff88806ecd7cd8 R08: 0000000000000000 R09: ffff88806eccef30
R10: ffff88806eccef10 R11: ffff88806ecce640 R12: ffffffff8778ed60
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002
 rcu_lock_acquire include/linux/rcupdate.h:244 [inline]
 rcu_read_lock include/linux/rcupdate.h:631 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline]
 batadv_nc_worker+0x107/0x6d0 net/batman-adv/network-coding.c:726
 process_one_work+0x868/0x1610 kernel/workqueue.c:2114
 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248
 kthread+0x31c/0x430 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
rcu_preempt kthread starved for 10545 jiffies! g86519 c86518 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=1
rcu_preempt     R  running task    29776     8      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2807 [inline]
 __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383
 schedule+0x92/0x1c0 kernel/sched/core.c:3427
 schedule_timeout+0x43e/0xe10 kernel/time/timer.c:1744
 rcu_gp_kthread+0xbf4/0x1ec0 kernel/rcu/tree.c:2255
 kthread+0x31c/0x430 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
sched: RT throttling activated

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/04/11 13:44 linux-4.14.y 1ec8f1f0bffe e955ac50 .config console log report ci2-linux-4-14
* Struck through repros no longer work on HEAD.