[syzbot] [bcachefs?] kernel BUG in __bkey_unpack_pos (2)

syzbot
2024-12-26T06:43:23Z

Hello,

syzbot found the following issue on:

HEAD commit: 4bbf9020becb Linux 6.13-rc4
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=167d3f30580000
kernel config: https://syzkaller.appspot.com/x/.config?x=d269ef41b9262400
dashboard link: https://syzkaller.appspot.com/bug?extid=c5e7a66b3b23ae65d44f
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15fd3fe8580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13fd3fe8580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-4bbf9020.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7afd8269bdaf/vmlinux-4bbf9020.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a3b5b5de34f1/bzImage-4bbf9020.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/63f4c8c02183/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c5e7a66b3b23ae65d44f@syzkaller.appspotmail.com

bcachefs (loop0): alloc_read... done
bcachefs (loop0): stripes_read... done
bcachefs (loop0): snapshots_read... done
bcachefs (loop0): check_allocations...
------------[ cut here ]------------
kernel BUG at fs/bcachefs/bkey.c:298!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5299 Comm: syz-executor313 Not tainted 6.13.0-rc4-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__bkey_unpack_pos+0x781/0x790 fs/bcachefs/bkey.c:298
Code: e8 74 9f 89 fd 48 c7 c7 80 fa f2 8e 4c 89 e6 48 89 da e8 b2 ea e4 00 e9 f4 fc ff ff e8 58 9f 89 fd 90 0f 0b e8 50 9f 89 fd 90 <0f> 0b e8 48 9f 89 fd 90 0f 0b 0f 1f 44 00 00 90 90 90 90 90 90 90
RSP: 0018:ffffc9000d01e2c0 EFLAGS: 00010293
RAX: ffffffff8415d4e0 RBX: 0000000000000003 RCX: ffff88801ab70000
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff8415ce35 R09: 0000000000000000
R10: ffffc9000d01e380 R11: fffff52001a03c72 R12: ffffc9000d01e380
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88804b901060
FS: 0000555573836380(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcd6804fa8 CR3: 0000000044000000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
bkey_unpack_pos_format_checked fs/bcachefs/bkey.h:456 [inline]
bkey_unpack_pos fs/bcachefs/bkey.h:464 [inline]
__bch2_bkey_cmp_packed_format_checked_inlined fs/bcachefs/bkey_cmp.h:103 [inline]
__bch2_bkey_cmp_packed_format_checked+0x2c7/0x800 fs/bcachefs/bkey.c:1020
bkey_cmp_p_or_unp fs/bcachefs/bset.h:291 [inline]
bkey_iter_cmp_p_or_unp fs/bcachefs/bset.h:400 [inline]
bch2_bset_search_linear fs/bcachefs/bset.c:1189 [inline]
bch2_btree_node_iter_init+0x234b/0x4280 fs/bcachefs/bset.c:1334
__bch2_btree_path_set_pos+0xb8e/0x1710 fs/bcachefs/btree_iter.c:1302
bch2_btree_path_set_pos fs/bcachefs/btree_iter.h:229 [inline]
bch2_btree_iter_peek_node+0x7c5/0xed0 fs/bcachefs/btree_iter.c:1915
bch2_gc_btree fs/bcachefs/btree_gc.c:686 [inline]
bch2_gc_btrees fs/bcachefs/btree_gc.c:729 [inline]
bch2_check_allocations+0x2125/0x7070 fs/bcachefs/btree_gc.c:1133
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: 0033:0x7fa1db696b7a
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:00007ffc50c8acf8 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffc50c8ad10 RCX: 00007fa1db696b7a
RDX: 00000000200002c0 RSI: 0000000020000380 RDI: 00007ffc50c8ad10
RBP: 0000000000000004 R08: 00007ffc50c8ad50 R09: 0000000000005931
R10: 0000000000000000 R11: 0000000000000282 R12: 0000000000000000
R13: 00007ffc50c8ad50 R14: 0000000000000003 R15: 0000000001000000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__bkey_unpack_pos+0x781/0x790 fs/bcachefs/bkey.c:298
Code: e8 74 9f 89 fd 48 c7 c7 80 fa f2 8e 4c 89 e6 48 89 da e8 b2 ea e4 00 e9 f4 fc ff ff e8 58 9f 89 fd 90 0f 0b e8 50 9f 89 fd 90 <0f> 0b e8 48 9f 89 fd 90 0f 0b 0f 1f 44 00 00 90 90 90 90 90 90 90
RSP: 0018:ffffc9000d01e2c0 EFLAGS: 00010293
RAX: ffffffff8415d4e0 RBX: 0000000000000003 RCX: ffff88801ab70000
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff8415ce35 R09: 0000000000000000
R10: ffffc9000d01e380 R11: fffff52001a03c72 R12: ffffc9000d01e380
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88804b901060
FS: 0000555573836380(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcd6804fa8 CR3: 0000000044000000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup