syzbot


kernel BUG in bch2_btree_write_buffer_flush_locked

Status: upstream: reported C repro on 2024/10/28 15:49
Subsystems: bcachefs
[Documentation on labels]
Reported-by: syzbot+4aff7bdaa254c1d9f008@syzkaller.appspotmail.com
Fix commit: bcachefs: Guard against journal seq overflow
Patched on: [ci-upstream-linux-next-kasan-gce-root], missing on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 40d, last: 8h34m
Cause bisection: introduced by (bisect log) :
commit bf4baaa087e2be0279991f1dbf9acaa7a4c9148c
Author: Kent Overstreet <kent.overstreet@linux.dev>
Date: Sat Oct 5 21:37:02 2024 +0000

  bcachefs: Fix lockdep splat in bch2_accounting_read

Crash: kernel BUG in bch2_btree_write_buffer_flush_locked (log)
Repro: C syz .config
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bcachefs?] kernel BUG in bch2_btree_write_buffer_flush_locked 0 (3) 2024/11/28 03:21
Last patch testing requests (4)
Created Duration User Patch Repo Result
2024/11/24 22:09 1h00m retest repro upstream OK log
2024/11/24 22:09 20m retest repro upstream OK log
2024/11/24 21:43 18m retest repro upstream OK log
2024/11/24 21:43 18m retest repro upstream OK log

Sample crash report:
bucket 0:127 gen 0 has wrong data_type: got free, should be sb, fixing
bucket 0:127 gen 0 data type sb has wrong dirty_sectors: got 0, should be 256, fixing
 done
bcachefs (loop0): going read-write
bcachefs (loop0): journal_replay...
------------[ cut here ]------------
kernel BUG at fs/bcachefs/btree_write_buffer.c:147!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 UID: 0 PID: 5840 Comm: syz-executor338 Not tainted 6.12.0-syzkaller-09567-g7eef7e306d3c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:wb_flush_one fs/bcachefs/btree_write_buffer.c:147 [inline]
RIP: 0010:bch2_btree_write_buffer_flush_locked+0x56bd/0x5a20 fs/bcachefs/btree_write_buffer.c:379
Code: c9 fc f4 ff e8 84 20 72 fd 90 0f 0b e8 7c 20 72 fd 90 0f 0b e8 74 20 72 fd 90 0f 0b e8 6c 20 72 fd 90 0f 0b e8 64 20 72 fd 90 <0f> 0b e8 5c 20 72 fd 90 0f 0b e8 e4 bf a5 07 e8 4f 20 72 fd 90 0f
RSP: 0018:ffffc90003e06760 EFLAGS: 00010293
RAX: ffffffff8423bc6c RBX: fff8af000000000b RCX: ffff88806c390000
RDX: 0000000000000000 RSI: 00f8af000000000b RDI: fff8af000000000b
RBP: ffffc90003e06bb0 R08: ffffffff84237f1b R09: 0000000000000000
R10: ffffc90003e06240 R11: fffff520007c0c49 R12: ffffc90004e000f0
R13: ffff88803225c000 R14: 00f8af000000000b R15: ffffc90004e00000
FS:  00005555684e7380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055fe8e12f0d8 CR3: 000000007b07a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 btree_write_buffer_flush_seq+0x1b23/0x1cc0 fs/bcachefs/btree_write_buffer.c:517
 bch2_btree_write_buffer_journal_flush+0xc7/0x150 fs/bcachefs/btree_write_buffer.c:533
 journal_flush_pins+0x5f7/0xb20 fs/bcachefs/journal_reclaim.c:565
 journal_flush_done+0x8e/0x260 fs/bcachefs/journal_reclaim.c:819
 bch2_journal_flush_pins+0x225/0x3a0 fs/bcachefs/journal_reclaim.c:852
 bch2_journal_flush_all_pins fs/bcachefs/journal_reclaim.h:76 [inline]
 bch2_journal_replay+0x270f/0x2a40 fs/bcachefs/recovery.c:383
 bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:191
 bch2_run_recovery_passes+0x3a7/0x880 fs/bcachefs/recovery_passes.c:244
 bch2_fs_recovery+0x25cc/0x39d0 fs/bcachefs/recovery.c:861
 bch2_fs_start+0x356/0x5b0 fs/bcachefs/super.c:1037
 bch2_fs_get_tree+0xd68/0x1710 fs/bcachefs/fs.c:2170
 vfs_get_tree+0x90/0x2b0 fs/super.c:1814
 do_new_mount+0x2be/0xb40 fs/namespace.c:3507
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f246db07dea
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdce796828 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffdce796840 RCX: 00007f246db07dea
RDX: 00000000200058c0 RSI: 00000000200002c0 RDI: 00007ffdce796840
RBP: 0000000000000004 R08: 00007ffdce796880 R09: 0000000000005931
R10: 0000000000010000 R11: 0000000000000282 R12: 0000000000010000
R13: 00007ffdce796880 R14: 0000000000000003 R15: 0000000001000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:wb_flush_one fs/bcachefs/btree_write_buffer.c:147 [inline]
RIP: 0010:bch2_btree_write_buffer_flush_locked+0x56bd/0x5a20 fs/bcachefs/btree_write_buffer.c:379
Code: c9 fc f4 ff e8 84 20 72 fd 90 0f 0b e8 7c 20 72 fd 90 0f 0b e8 74 20 72 fd 90 0f 0b e8 6c 20 72 fd 90 0f 0b e8 64 20 72 fd 90 <0f> 0b e8 5c 20 72 fd 90 0f 0b e8 e4 bf a5 07 e8 4f 20 72 fd 90 0f
RSP: 0018:ffffc90003e06760 EFLAGS: 00010293
RAX: ffffffff8423bc6c RBX: fff8af000000000b RCX: ffff88806c390000
RDX: 0000000000000000 RSI: 00f8af000000000b RDI: fff8af000000000b
RBP: ffffc90003e06bb0 R08: ffffffff84237f1b R09: 0000000000000000
R10: ffffc90003e06240 R11: fffff520007c0c49 R12: ffffc90004e000f0
R13: ffff88803225c000 R14: 00f8af000000000b R15: ffffc90004e00000
FS:  00005555684e7380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055fe8e12f0d8 CR3: 000000007b07a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (15):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/26 11:30 upstream 7eef7e306d3c e9a9a9f2 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs kernel BUG in bch2_btree_write_buffer_flush_locked
2024/11/25 08:55 upstream 9f16d5e6f220 68da6d95 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root kernel BUG in bch2_btree_write_buffer_flush_locked
2024/11/10 21:18 upstream a9cda7c0ffed 6b856513 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs kernel BUG in bch2_btree_write_buffer_flush_locked
2024/11/10 20:57 upstream a9cda7c0ffed 6b856513 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs kernel BUG in bch2_btree_write_buffer_flush_locked
2024/12/05 18:08 upstream feffde684ac2 1c533826 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in bch2_btree_write_buffer_flush_locked
2024/12/04 22:59 upstream feffde684ac2 b50eb251 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in bch2_btree_write_buffer_flush_locked
2024/11/30 13:57 upstream 2ba9f676d0a2 68914665 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in bch2_btree_write_buffer_flush_locked
2024/11/29 04:21 upstream 65ae975e97d5 5df23865 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in bch2_btree_write_buffer_flush_locked
2024/11/25 08:00 upstream 9f16d5e6f220 68da6d95 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in bch2_btree_write_buffer_flush_locked
2024/11/09 23:17 upstream da4373fbcf00 6b856513 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in bch2_btree_write_buffer_flush_locked
2024/11/03 22:22 upstream b9021de3ec2f f00eed24 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in bch2_btree_write_buffer_flush_locked
2024/11/01 02:50 upstream 90602c251cda 96eb609f .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in bch2_btree_write_buffer_flush_locked
2024/10/26 23:45 upstream 850925a8133c 65e8686b .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root kernel BUG in bch2_btree_write_buffer_flush_locked
2024/10/26 23:10 upstream 850925a8133c 65e8686b .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root kernel BUG in bch2_btree_write_buffer_flush_locked
2024/10/26 22:33 upstream 850925a8133c 65e8686b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in bch2_btree_write_buffer_flush_locked
* Struck through repros no longer work on HEAD.