[syzbot] [bcachefs?] kernel BUG in __bch2_bkey_compat

[syzbot <syzbot+4908f37148402680dfec@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    27605c8c0f69 Merge tag 'net-6.16-rc2' of git://git.kernel...
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=17749d70580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=162faeb2d1eaefb4
dashboard link: https://syzkaller.appspot.com/bug?extid=4908f37148402680dfec
compiler:       Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10f9f682580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17ecb9d4580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8f486f1f2af2/disk-27605c8c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/774310efd683/vmlinux-27605c8c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/861612fbccfb/bzImage-27605c8c.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/1659e3de16d4/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4908f37148402680dfec@syzkaller.appspotmail.com

bcachefs (loop0): sb invalid before write: Unsupported superblock version_min 0.0: (unknown version) (min 0.9: (unknown version), max 1.28: inode_has_case_insensitive)
  emergency read only at seq 10
------------[ cut here ]------------
kernel BUG at fs/bcachefs/bkey_methods.c:469!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 5832 Comm: read_btree_node Not tainted 6.16.0-rc1-syzkaller-00101-g27605c8c0f69 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__bch2_bkey_compat+0xbbf/0xbd0 fs/bcachefs/bkey_methods.c:469
Code: fd 90 0f 0b e8 82 2c a7 fd 90 0f 0b e8 7a 2c a7 fd 90 0f 0b e8 72 2c a7 fd 90 0f 0b e8 6a 2c a7 fd 90 0f 0b e8 62 2c a7 fd 90 <0f> 0b cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc9000438ea40 EFLAGS: 00010293
RAX: ffffffff8419218e RBX: ffff88802fc508c0 RCX: ffff888031661e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0900000000000000
RBP: ffffc9000438ece8 R08: 0000000020000000 R09: 0000000020000000
R10: ffffffff00000000 R11: 34b6b456b49c471e R12: 00000000ffffffff
R13: 0000000000000003 R14: 0000000000000001 R15: 00000000ffffffff
FS:  0000000000000000(0000) GS:ffff888125d86000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd66213388 CR3: 000000002f80a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bch2_bkey_compat fs/bcachefs/bkey_methods.h:134 [inline]
 validate_bset_keys+0x5b7/0x1480 fs/bcachefs/btree_io.c:983
 bch2_btree_node_read_done+0x1d3c/0x5150 fs/bcachefs/btree_io.c:1211
 btree_node_read_work+0x426/0xe30 fs/bcachefs/btree_io.c:1399
 bch2_btree_node_read+0x887/0x2a00 fs/bcachefs/btree_io.c:-1
 bch2_btree_node_fill+0xd12/0x14f0 fs/bcachefs/btree_cache.c:994
 bch2_btree_node_get_noiter+0xa2c/0x1000 fs/bcachefs/btree_cache.c:1261
 found_btree_node_is_readable fs/bcachefs/btree_node_scan.c:85 [inline]
 try_read_btree_node fs/bcachefs/btree_node_scan.c:220 [inline]
 read_btree_nodes_worker+0x1319/0x1e20 fs/bcachefs/btree_node_scan.c:269
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__bch2_bkey_compat+0xbbf/0xbd0 fs/bcachefs/bkey_methods.c:469
Code: fd 90 0f 0b e8 82 2c a7 fd 90 0f 0b e8 7a 2c a7 fd 90 0f 0b e8 72 2c a7 fd 90 0f 0b e8 6a 2c a7 fd 90 0f 0b e8 62 2c a7 fd 90 <0f> 0b cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc9000438ea40 EFLAGS: 00010293
RAX: ffffffff8419218e RBX: ffff88802fc508c0 RCX: ffff888031661e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0900000000000000
RBP: ffffc9000438ece8 R08: 0000000020000000 R09: 0000000020000000
R10: ffffffff00000000 R11: 34b6b456b49c471e R12: 00000000ffffffff
R13: 0000000000000003 R14: 0000000000000001 R15: 00000000ffffffff
FS:  0000000000000000(0000) GS:ffff888125d86000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd66213388 CR3: 000000002f80a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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