syzbot


INFO: rcu detected stall in ext4_file_write_iter

Status: upstream: reported on 2024/04/01 06:27
Reported-by: syzbot+1d24afe6a3147f39e39b@syzkaller.appspotmail.com
First crash: 50d, last: 50d
Similar bugs (14)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in ext4_file_write_iter (8) mm 3 158d 214d 0/26 auto-obsoleted due to no activity on 2024/03/14 12:59
linux-5.15 INFO: rcu detected stall in ext4_file_write_iter 1 182d 182d 0/3 auto-obsoleted due to no activity on 2024/02/29 20:44
upstream INFO: rcu detected stall in ext4_file_write_iter (3) block 5 1016d 1106d 0/26 auto-closed as invalid on 2021/11/07 19:52
upstream INFO: rcu detected stall in ext4_file_write_iter (5) mm 3 756d 757d 0/26 auto-closed as invalid on 2022/06/25 07:58
upstream INFO: rcu detected stall in ext4_file_write_iter (7) mm bpf ext4 3 264d 306d 23/26 fixed on 2023/10/12 12:47
upstream INFO: rcu detected stall in ext4_file_write_iter (4) mm C unreliable 58 852d 881d 0/26 closed as invalid on 2022/02/08 10:32
android-49 INFO: rcu detected stall in ext4_file_write_iter syz 2 1814d 1855d 0/3 public: reported syz repro on 2019/04/23 08:58
upstream INFO: rcu detected stall in ext4_file_write_iter (2) ext4 1 1317d 1317d 0/26 auto-closed as invalid on 2021/01/10 12:58
linux-4.14 INFO: rcu detected stall in ext4_file_write_iter C 7 457d 1866d 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 1379d 1911d 15/26 fixed on 2020/09/25 01:17
linux-4.19 INFO: rcu detected stall in ext4_file_write_iter C error 9 517d 1858d 0/1 upstream: reported C repro on 2019/04/20 13:09
upstream INFO: rcu detected stall in ext4_file_write_iter (6) ext4 C error 8 405d 468d 22/26 fixed on 2023/06/08 14:41
linux-4.19 BUG: soft lockup in ext4_file_write_iter 1 1062d 1062d 0/1 auto-closed as invalid on 2021/10/22 22:26
android-5-15 BUG: soft lockup in ext4_file_write_iter 5 23h57m 45d 0/2 premoderation: reported on 2024/04/06 14:01

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2676 jiffies s: 4181 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4937 Comm: syz-executor.3 Not tainted 6.1.83-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:perf_sample_data_init include/linux/perf_event.h:1094 [inline]
RIP: 0010:perf_tp_event+0x16b/0xc80 kernel/events/core.c:9948
Code: df 4c 8d b4 24 c0 00 00 00 0f 85 d2 0a 00 00 c7 84 24 1c 02 00 00 00 00 00 00 49 8d 7e 08 48 89 f8 48 c1 e8 03 42 80 3c 38 00 <74> 05 e8 9e 48 31 00 48 c7 84 24 c8 00 00 00 00 00 00 00 49 8d 5e
RSP: 0018:ffffc90000007900 EFLAGS: 00000046
RAX: 1ffff92000000f39 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc900000079c8
RBP: ffffc90000007ba8 R08: dffffc0000000000 R09: ffffc90000007b00
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffe8ffffc31418
R13: ffffc90000007b00 R14: ffffc900000079c0 R15: dffffc0000000000
FS:  00007f85ac15c6c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000007db22000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 perf_trace_run_bpf_submit+0xf7/0x1d0 kernel/events/core.c:9929
 perf_trace_preemptirq_template+0x2d1/0x3d0 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0xd5/0x140 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:679
RIP: 0010:variable_ffs arch/x86/include/asm/bitops.h:319 [inline]
RIP: 0010:__do_softirq+0x1f3/0xa4c kernel/softirq.c:559
Code: 00 00 00 44 0f b7 f3 48 c7 c7 e0 e6 ea 8a e8 54 ff c9 ff 65 66 c7 05 9a 9d 43 75 00 00 e8 55 43 d1 f6 fb 49 c7 c7 c0 a0 e0 8c <44> 89 74 24 54 b8 ff ff ff ff 0f bc 44 24 54 41 89 c4 41 ff c4 0f
RSP: 0018:ffffc90000007e00 EFLAGS: 00000286
RAX: da819fe1de2b2a00 RBX: 0000000000440200 RCX: ffffffff816abeda
RDX: dffffc0000000000 RSI: ffffffff8aebee40 RDI: ffffffff8b3d2b40
RBP: ffffc90000007f30 R08: dffffc0000000000 R09: fffffbfff2092e58
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880559f9dc0
R13: 1ffff92000000fe8 R14: 0000000000000200 R15: ffffffff8ce0a0c0
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x155/0x240 kernel/softirq.c:650
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
 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:rcu_read_unlock_special+0x0/0x540 kernel/rcu/tree_plugin.h:627
Code: 00 eb 97 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 77 ff ff ff 4c 89 ff e8 be ee 6d 00 e9 6a ff ff ff 66 0f 1f 84 00 00 00 00 00 <55> 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec a0 00
RSP: 0018:ffffc9000506f180 EFLAGS: 00000206
RAX: 0000000000000000 RBX: 1ffff1100ab3f43f RCX: 0000000000040000
RDX: ffffc90004d12000 RSI: 00000000000379df RDI: ffff8880559f9dc0
RBP: 0000000000000000 R08: ffffffff81ba7f36 R09: fffffbfff2092e58
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8880559fa1fc R14: ffff8880559f9dc0 R15: ffff8880559fa200
 __rcu_read_unlock+0x92/0x100 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 unlocked_inode_to_wb_end include/linux/backing-dev.h:309 [inline]
 folio_clear_dirty_for_io+0x7e5/0xcf0 mm/page-writeback.c:2882
 mpage_submit_page+0x90/0x230 fs/ext4/inode.c:2110
 mpage_map_and_submit_buffers fs/ext4/inode.c:2375 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2514 [inline]
 ext4_writepages+0x2076/0x3de0 fs/ext4/inode.c:2843
 do_writepages+0x3a2/0x670 mm/page-writeback.c:2469
 filemap_fdatawrite_wbc+0x121/0x180 mm/filemap.c:388
 __filemap_fdatawrite_range mm/filemap.c:421 [inline]
 file_write_and_wait_range+0x1ca/0x2b0 mm/filemap.c:774
 ext4_sync_file+0x249/0xcc0 fs/ext4/fsync.c:151
 generic_write_sync include/linux/fs.h:2957 [inline]
 ext4_buffered_write_iter+0x30a/0x3a0 fs/ext4/file.c:292
 ext4_file_write_iter+0x1d2/0x1880
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x7ae/0xba0 fs/read_write.c:584
 ksys_write+0x19c/0x2c0 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f85ab47dda9
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:00007f85ac15c0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f85ab5abf80 RCX: 00007f85ab47dda9
RDX: 0000000000040010 RSI: 0000000020000180 RDI: 0000000000000006
RBP: 00007f85ab4ca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f85ab5abf80 R15: 00007ffc605afe98
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/01 06:26 linux-6.1.y e5cd595e23c1 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in ext4_file_write_iter
* Struck through repros no longer work on HEAD.