syzbot


kernel BUG in __replicas_entry_idx

Status: fixed on 2024/08/27 06:15
Subsystems: bcachefs
[Documentation on labels]
Reported-by: syzbot+6365e0d1ebcb50170e86@syzkaller.appspotmail.com
Fix commit: 8bb8d683a401 bcachefs: Delete journal-buf-sharded old style accounting
First crash: 204d, last: 198d
Cause bisection: introduced by (bisect log) :
commit 03ef80b469d5d83530ce1ce15be78a40e5300f9b
Author: Kent Overstreet <kent.overstreet@linux.dev>
Date: Sat Sep 23 22:41:51 2023 +0000

  bcachefs: Ignore unknown mount options

Crash: kernel BUG in __replicas_entry_idx (log)
Repro: C syz .config
  
Fix bisection: fixed by (bisect log) [merge commit]:
commit 2ec0028a1cadfb88d912435c1eb1ac5de76071f0
Author: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: Thu May 23 00:39:34 2024 +0000

  Merge branch 'next' into for-linus

  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bcachefs?] kernel BUG in __replicas_entry_idx 0 (2) 2024/08/22 17:29
Last patch testing requests (1)
Created Duration User Patch Repo Result
2024/06/06 14:15 19m retest repro upstream OK log

Sample crash report:
loop0: detected capacity change from 0 to 32768
bcachefs (loop0): mounting version 1.7: mi_btree_bitmap opts=metadata_checksum=none,data_checksum=none,nojournal_transaction_names
bcachefs (loop0): recovering from clean shutdown, journal seq 10
------------[ cut here ]------------
kernel BUG at fs/bcachefs/replicas.c:28!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 PID: 5080 Comm: syz-executor136 Not tainted 6.9.0-syzkaller-08284-gea5f6ad9ad96 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:verify_replicas_entry fs/bcachefs/replicas.c:28 [inline]
RIP: 0010:__replicas_entry_idx+0x331/0x350 fs/bcachefs/replicas.c:233
Code: d9 80 e1 07 80 c1 03 38 c1 0f 8c d7 fe ff ff 48 89 df e8 a2 d5 be fd e9 ca fe ff ff e8 68 11 5d fd 90 0f 0b e8 60 11 5d fd 90 <0f> 0b e8 58 11 5d fd 90 0f 0b e8 50 11 5d fd 90 0f 0b 66 2e 0f 1f
RSP: 0018:ffffc9000333ef70 EFLAGS: 00010293
RAX: ffffffff84391de0 RBX: 0000000000000004 RCX: ffff8880295d3c00
RDX: 0000000000000000 RSI: 000000000000007f RDI: 0000000000000009
RBP: 000000000000007f R08: ffffffff84391b58 R09: ffffffff8438288d
R10: 0000000000000007 R11: ffff8880295d3c00 R12: ffff888024a22088
R13: ffff888024a22088 R14: 0000000000000001 R15: ffff888078a80000
FS:  0000555570a13380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d9915fa648 CR3: 0000000023958000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bch2_replicas_entry_idx fs/bcachefs/replicas.c:248 [inline]
 bch2_replicas_set_usage+0x2ff/0x710 fs/bcachefs/replicas.c:625
 journal_replay_early+0xba/0x4f0 fs/bcachefs/recovery.c:411
 bch2_fs_recovery+0x39c2/0x63b0 fs/bcachefs/recovery.c:747
 bch2_fs_start+0x356/0x5b0 fs/bcachefs/super.c:1043
 bch2_fs_open+0xa8d/0xdf0 fs/bcachefs/super.c:2105
 bch2_mount+0x71d/0x1320 fs/bcachefs/fs.c:1906
 legacy_get_tree+0xee/0x190 fs/fs_context.c:662
 vfs_get_tree+0x90/0x2a0 fs/super.c:1779
 do_new_mount+0x2be/0xb40 fs/namespace.c:3352
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1f34ceddea
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:00007ffefbf78468 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffefbf78480 RCX: 00007f1f34ceddea
RDX: 0000000020011a00 RSI: 0000000020000280 RDI: 00007ffefbf78480
RBP: 0000000000000004 R08: 00007ffefbf784c0 R09: 00000000000119f8
R10: 0000000001200014 R11: 0000000000000282 R12: 0000000001200014
R13: 00007ffefbf784c0 R14: 0000000000000003 R15: 0000000001000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:verify_replicas_entry fs/bcachefs/replicas.c:28 [inline]
RIP: 0010:__replicas_entry_idx+0x331/0x350 fs/bcachefs/replicas.c:233
Code: d9 80 e1 07 80 c1 03 38 c1 0f 8c d7 fe ff ff 48 89 df e8 a2 d5 be fd e9 ca fe ff ff e8 68 11 5d fd 90 0f 0b e8 60 11 5d fd 90 <0f> 0b e8 58 11 5d fd 90 0f 0b e8 50 11 5d fd 90 0f 0b 66 2e 0f 1f
RSP: 0018:ffffc9000333ef70 EFLAGS: 00010293
RAX: ffffffff84391de0 RBX: 0000000000000004 RCX: ffff8880295d3c00
RDX: 0000000000000000 RSI: 000000000000007f RDI: 0000000000000009
RBP: 000000000000007f R08: ffffffff84391b58 R09: ffffffff8438288d
R10: 0000000000000007 R11: ffff8880295d3c00 R12: ffff888024a22088
R13: ffff888024a22088 R14: 0000000000000001 R15: ffff888078a80000
FS:  0000555570a13380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d9915fa648 CR3: 0000000023958000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/17 23:57 upstream ea5f6ad9ad96 a12e99e7 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs kernel BUG in __replicas_entry_idx
2024/05/23 13:52 upstream 8f6a15f095a6 4d098039 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root kernel BUG in __replicas_entry_idx
2024/05/17 23:13 upstream ea5f6ad9ad96 a12e99e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs kernel BUG in __replicas_entry_idx
* Struck through repros no longer work on HEAD.