syzbot


INFO: rcu detected stall in ext4_file_write_iter (3)

Status: auto-closed as invalid on 2021/11/07 19:52
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 569d, last: 479d
similar bugs (8):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in ext4_file_write_iter (5) 3 220d 220d 0/24 auto-closed as invalid on 2022/06/25 07:58
upstream INFO: rcu detected stall in ext4_file_write_iter (4) C unreliable 58 315d 345d 0/24 closed as invalid on 2022/02/08 10:32
android-49 INFO: rcu detected stall in ext4_file_write_iter syz 2 1278d 1319d 0/3 public: reported syz repro on 2019/04/23 08:58
upstream INFO: rcu detected stall in ext4_file_write_iter (2) 1 781d 781d 0/24 auto-closed as invalid on 2021/01/10 12:58
linux-4.14 INFO: rcu detected stall in ext4_file_write_iter C 7 36d 1330d 0/1 upstream: reported C repro on 2019/04/12 16:30
upstream INFO: rcu detected stall in ext4_file_write_iter C inconclusive done 93 843d 1375d 17/24 fixed on 2020/09/25 01:17
linux-4.19 INFO: rcu detected stall in ext4_file_write_iter C error 7 437d 1322d 0/1 upstream: reported C repro on 2019/04/20 13:09
linux-4.19 BUG: soft lockup in ext4_file_write_iter 1 525d 525d 0/1 auto-closed as invalid on 2021/10/22 22:26

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=72361, q=5)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294999441-4294988938), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10504 jiffies! g72361 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:28864 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4683 [inline]
 __schedule+0x93a/0x26f0 kernel/sched/core.c:5940
 schedule+0xd3/0x270 kernel/sched/core.c:6019
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1878
 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline]
 rcu_gp_kthread+0xd34/0x1980 kernel/rcu/tree.c:2169
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
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: 19380 Comm: syz-executor.4 Not tainted 5.14.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:102 [inline]
RIP: 0010:do_raw_spin_unlock+0xec/0x230 kernel/locking/spinlock_debug.c:138
Code: fc ff df 4c 89 e2 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e fc 00 00 00 65 8b 05 e5 1a a6 7e 39 45 08 0f 85 b5 00 00 00 <48> b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02 00 0f
RSP: 0018:ffffc90000007df8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000046 RCX: ffffffff815b79f0
RDX: 1ffff11017388479 RSI: 0000000000000004 RDI: ffff8880b9c423c0
RBP: ffff8880b9c423c0 R08: 0000000000000000 R09: ffff8880b9c423c3
R10: ffffed1017388478 R11: 0000000000000000 R12: ffff8880b9c423c8
R13: ffff8880b9c423d0 R14: ffff8880b9c423c0 R15: ffffffff81931a70
FS:  00007fae3fc50700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000047b880 CR3: 000000002a3cc000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:159 [inline]
 _raw_spin_unlock_irqrestore+0x1e/0x70 kernel/locking/spinlock.c:191
 __run_hrtimer kernel/time/hrtimer.c:1533 [inline]
 __hrtimer_run_queues+0x51a/0xe50 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:trylock_clear_pending kernel/locking/qspinlock_paravirt.h:121 [inline]
RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:435 [inline]
RIP: 0010:__pv_queued_spin_lock_slowpath+0x3c9/0xb40 kernel/locking/qspinlock.c:508
Code: 83 e3 07 41 be 01 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 2c 01 eb 0c f3 90 41 83 ec 01 0f 84 72 04 00 00 41 0f b6 45 00 <38> d8 7f 08 84 c0 0f 85 91 05 00 00 0f b6 45 00 84 c0 75 db be 02
RSP: 0018:ffffc9000bbb6ef0 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffff1100423d9a6
RDX: 0000000000000001 RSI: ffffffff817bac21 RDI: ffffffff81330591
RBP: ffff8880211ecd30 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff817babe9 R11: 0000000000000000 R12: 000000000000085b
R13: ffffed100423d9a6 R14: 0000000000000001 R15: ffff8880b9c52880
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:113
 spin_lock include/linux/spinlock.h:354 [inline]
 dd_dispatch_request+0xa3/0x260 block/mq-deadline-main.c:502
 __blk_mq_do_dispatch_sched+0x56c/0x930 block/blk-mq-sched.c:149
 blk_mq_do_dispatch_sched block/blk-mq-sched.c:214 [inline]
 __blk_mq_sched_dispatch_requests+0x2a0/0x410 block/blk-mq-sched.c:334
 blk_mq_sched_dispatch_requests+0xfb/0x180 block/blk-mq-sched.c:360
 __blk_mq_run_hw_queue+0xd8/0x150 block/blk-mq.c:1500
 __blk_mq_delay_run_hw_queue+0x547/0x640 block/blk-mq.c:1577
 blk_mq_run_hw_queue+0x16c/0x2f0 block/blk-mq.c:1630
 blk_mq_sched_insert_requests+0x1d5/0x680 block/blk-mq-sched.c:513
 blk_mq_flush_plug_list+0x3d8/0x560 block/blk-mq.c:1955
 blk_flush_plug_list block/blk-core.c:1731 [inline]
 blk_finish_plug block/blk-core.c:1748 [inline]
 blk_finish_plug+0x83/0xe0 block/blk-core.c:1744
 __iomap_dio_rw+0xd76/0x1300 fs/iomap/direct-io.c:583
 iomap_dio_rw+0x30/0x90 fs/iomap/direct-io.c:649
 ext4_dio_write_iter fs/ext4/file.c:568 [inline]
 ext4_file_write_iter+0xe18/0x14e0 fs/ext4/file.c:678
 call_write_iter include/linux/fs.h:2114 [inline]
 do_iter_readv_writev+0x46f/0x740 fs/read_write.c:740
 do_iter_write+0x188/0x670 fs/read_write.c:866
 vfs_iter_write+0x70/0xa0 fs/read_write.c:907
 iter_file_splice_write+0x723/0xc70 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x110/0x180 fs/splice.c:936
 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891
 do_splice_direct+0x1b3/0x280 fs/splice.c:979
 do_sendfile+0x9f0/0x1120 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1311
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fae3fc50188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000401ffc000 R11: 0000000000000246 R12: 000000000056bf80
R13: 0000000000a9fb1f R14: 00007fae3fc50300 R15: 0000000000022000

================================
WARNING: inconsistent lock state
5.14.0-rc1-syzkaller #0 Not tainted
--------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
syz-executor.5/19372 [HC0[0]:SC1[1]:HE0:SE0] takes:
ffffffff8b984758 (rcu_node_0){?.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:543 [inline]
ffffffff8b984758 (rcu_node_0){?.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:709 [inline]
ffffffff8b984758 (rcu_node_0){?.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3922 [inline]
ffffffff8b984758 (rcu_node_0){?.-.}-{2:2}, at: rcu_sched_clock_irq+0xc9a/0x20c0 kernel/rcu/tree.c:2641
{IN-HARDIRQ-W} state was registered at:
  lock_acquire kernel/locking/lockdep.c:5625 [inline]
  lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
  __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
  _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159
  rcu_report_exp_cpu_mult+0x1c/0x280 kernel/rcu/tree_exp.h:237
  flush_smp_call_function_queue+0x34b/0x640 kernel/smp.c:663
  __sysvec_call_function_single+0x95/0x3d0 arch/x86/kernel/smp.c:248
  sysvec_call_function_single+0x8e/0xc0 arch/x86/kernel/smp.c:243
  asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:646
  native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
  arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
  arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline]
  lock_release+0x14d/0x720 kernel/locking/lockdep.c:5641
  might_alloc include/linux/sched/mm.h:199 [inline]
  slab_pre_alloc_hook mm/slab.h:485 [inline]
  slab_alloc_node mm/slub.c:2902 [inline]
  slab_alloc mm/slub.c:2989 [inline]
  kmem_cache_alloc+0x46/0x3a0 mm/slub.c:2994
  vm_area_alloc+0x1c/0x110 kernel/fork.c:349
  __bprm_mm_init fs/exec.c:252 [inline]
  bprm_mm_init fs/exec.c:376 [inline]
  alloc_bprm+0x33e/0x8f0 fs/exec.c:1521
  kernel_execve+0x55/0x460 fs/exec.c:1941
  call_usermodehelper_exec_async+0x2e3/0x580 kernel/umh.c:112
  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
irq event stamp: 12114325
hardirqs last  enabled at (12114324): [<ffffffff89400c02>] asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
hardirqs last disabled at (12114325): [<ffffffff8929853b>] sysvec_apic_timer_interrupt+0xb/0xc0 arch/x86/kernel/apic/apic.c:1100
softirqs last  enabled at (11893986): [<ffffffff8146289e>] invoke_softirq kernel/softirq.c:432 [inline]
softirqs last  enabled at (11893986): [<ffffffff8146289e>] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636
softirqs last disabled at (11893989): [<ffffffff8146289e>] invoke_softirq kernel/softirq.c:432 [inline]
softirqs last disabled at (11893989): [<ffffffff8146289e>] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(rcu_node_0);
  <Interrupt>
    lock(rcu_node_0);

 *** DEADLOCK ***

6 locks held by syz-executor.5/19372:
 #0: ffff888029782460 (sb_writers#5){.+.+}-{0:0}, at: __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 #0: ffff888029782460 (sb_writers#5){.+.+}-{0:0}, at: __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 #0: ffff888029782460 (sb_writers#5){.+.+}-{0:0}, at: __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1311
 #1: ffff88807c149878 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:784 [inline]
 #1: ffff88807c149878 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: ext4_dio_write_iter fs/ext4/file.c:508 [inline]
 #1: ffff88807c149878 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: ext4_file_write_iter+0xb13/0x14e0 fs/ext4/file.c:678
 #2: ffffffff8b97b900 (rcu_read_lock){....}-{1:2}, at: hctx_lock+0x7f/0x1d0 block/blk-mq.c:698
 #3: ffff8880211ecd48 (&dd->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline]
 #3: ffff8880211ecd48 (&dd->lock){+.+.}-{2:2}, at: dd_dispatch_request+0xa3/0x260 block/mq-deadline-main.c:502
 #4: ffffffff8b97b900 (rcu_read_lock){....}-{1:2}, at: ieee80211_iterate_active_interfaces_atomic+0x0/0x180 net/mac80211/util.c:1237
 #5: ffffffff8b984758 (rcu_node_0){?.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:543 [inline]
 #5: ffffffff8b984758 (rcu_node_0){?.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:709 [inline]
 #5: ffffffff8b984758 (rcu_node_0){?.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3922 [inline]
 #5: ffffffff8b984758 (rcu_node_0){?.-.}-{2:2}, at: rcu_sched_clock_irq+0xc9a/0x20c0 kernel/rcu/tree.c:2641

stack backtrace:
CPU: 1 PID: 19372 Comm: syz-executor.5 Not tainted 5.14.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
 print_usage_bug kernel/locking/lockdep.c:203 [inline]
 valid_state kernel/locking/lockdep.c:3933 [inline]
 mark_lock_irq kernel/locking/lockdep.c:4136 [inline]
 mark_lock.cold+0x61/0x8e kernel/locking/lockdep.c:4593
 mark_held_locks+0x9f/0xe0 kernel/locking/lockdep.c:4194
 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4212 [inline]
 lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4280 [inline]
 lockdep_hardirqs_on_prepare+0x135/0x400 kernel/locking/lockdep.c:4232
 trace_hardirqs_on+0x5b/0x1c0 kernel/trace/trace_preemptirq.c:49
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:mac80211_hwsim_monitor_rx+0x16e/0x840 drivers/net/wireless/mac80211_hwsim.c:1025
Code: fc 49 8d 7c 24 04 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 <0f> 85 89 05 00 00 45 0f b7 6c 24 04 e8 61 53 43 fc 4c 8b 35 0a 6a
RSP: 0018:ffffc90000dc0cb0 EFLAGS: 00000246
RAX: 0000000000000005 RBX: ffff888079c7b288 RCX: 0000000000000100
RDX: 0000000000000000 RSI: ffffffff85323515 RDI: ffff888079c7dd94
RBP: ffff88807e0008c0 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff85323442 R11: 0000000000000000 R12: ffff888079c7dd90
R13: 0000000000000000 R14: 0000000000000000 R15: ffff888079c7b260
 mac80211_hwsim_tx_frame+0xde/0x2a0 drivers/net/wireless/mac80211_hwsim.c:1777
 mac80211_hwsim_beacon_tx+0x49b/0x930 drivers/net/wireless/mac80211_hwsim.c:1838
 __iterate_interfaces+0x1e5/0x520 net/mac80211/util.c:793
 ieee80211_iterate_active_interfaces_atomic+0x70/0x180 net/mac80211/util.c:829
 mac80211_hwsim_beacon+0xd5/0x1a0 drivers/net/wireless/mac80211_hwsim.c:1861
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1601
 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1618
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__hlist_del include/linux/list.h:838 [inline]
RIP: 0010:hlist_del_init include/linux/list.h:866 [inline]
RIP: 0010:hash_del include/linux/hashtable.h:107 [inline]
RIP: 0010:__elv_rqhash_del block/elevator.c:202 [inline]
RIP: 0010:elv_rqhash_del+0xcd/0x160 block/elevator.c:209
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 9c 00 00 00 4c 89 e2 48 8b 6b 58 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <75> 70 48 85 ed 49 89 2c 24 74 24 e8 93 12 b7 fd 48 8d 7d 08 48 b8
RSP: 0018:ffffc9000c37efa0 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffff888021577c00 RCX: ffffc90014667000
RDX: 1ffff110042a2140 RSI: ffffffff83be75d5 RDI: ffff888021577c58
RBP: 0000000000000000 R08: 0000000000000000 R09: ffff8880211ecca0
R10: ffffffff83be7591 R11: 0000000000000000 R12: ffff888021510a00
R13: ffff888021577c68 R14: ffff8880211ecc58 R15: 0000000000000001
 deadline_remove_request+0x150/0x380 block/mq-deadline-main.c:206
 deadline_move_request block/mq-deadline-main.c:274 [inline]
 __dd_dispatch_request+0x990/0xd60 block/mq-deadline-main.c:472
 dd_dispatch_request+0x1a4/0x260 block/mq-deadline-main.c:518
 __blk_mq_do_dispatch_sched+0x56c/0x930 block/blk-mq-sched.c:149
 blk_mq_do_dispatch_sched block/blk-mq-sched.c:214 [inline]
 __blk_mq_sched_dispatch_requests+0x2a0/0x410 block/blk-mq-sched.c:334
 blk_mq_sched_dispatch_requests+0xfb/0x180 block/blk-mq-sched.c:360
 __blk_mq_run_hw_queue+0xd8/0x150 block/blk-mq.c:1500
 __blk_mq_delay_run_hw_queue+0x547/0x640 block/blk-mq.c:1577
 blk_mq_run_hw_queue+0x16c/0x2f0 block/blk-mq.c:1630
 blk_mq_sched_insert_requests+0x1d5/0x680 block/blk-mq-sched.c:513
 blk_mq_flush_plug_list+0x3d8/0x560 block/blk-mq.c:1955
 blk_flush_plug_list block/blk-core.c:1731 [inline]
 blk_finish_plug block/blk-core.c:1748 [inline]
 blk_finish_plug+0x83/0xe0 block/blk-core.c:1744
 __iomap_dio_rw+0xd76/0x1300 fs/iomap/direct-io.c:583
 iomap_dio_rw+0x30/0x90 fs/iomap/direct-io.c:649
 ext4_dio_write_iter fs/ext4/file.c:568 [inline]
 ext4_file_write_iter+0xe18/0x14e0 fs/ext4/file.c:678
 call_write_iter include/linux/fs.h:2114 [inline]
 do_iter_readv_writev+0x46f/0x740 fs/read_write.c:740
 do_iter_write+0x188/0x670 fs/read_write.c:866
 vfs_iter_write+0x70/0xa0 fs/read_write.c:907
 iter_file_splice_write+0x723/0xc70 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x110/0x180 fs/splice.c:936
 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891
 do_splice_direct+0x1b3/0x280 fs/splice.c:979
 do_sendfile+0x9f0/0x1120 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1311
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f985149d188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000401ffc000 R11: 0000000000000246 R12: 000000000056bf80
R13: 0000000000a9fb1f R14: 00007f985149d300 R15: 0000000000022000
softirq: huh, entered softirq 8 HRTIMER ffffffff81655450 with preempt_count 00000102, exited with 00000103?

Crashes (5):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce 2021/07/13 01:13 upstream 7fef2edf7cc7 f415556d .config log report info INFO: rcu detected stall in ext4_file_write_iter
ci-upstream-kasan-gce-selinux-root 2021/05/14 00:41 upstream c06a2ba62fc4 80f9b418 .config log report info INFO: rcu detected stall in ext4_file_write_iter
ci-upstream-kasan-gce 2021/05/12 02:40 upstream 88b06399c9c7 b3c3bb8e .config log report info INFO: rcu detected stall in ext4_file_write_iter
ci-upstream-bpf-kasan-gce 2021/08/09 19:49 bpf d09c548dbf3b 6972b106 .config log report info INFO: rcu detected stall in ext4_file_write_iter
ci-upstream-bpf-kasan-gce 2021/07/22 23:25 bpf d6371c76e20d 302e51de .config log report info INFO: rcu detected stall in ext4_file_write_iter
* Struck through repros no longer work on HEAD.