[syzbot] [bcachefs?] kernel BUG in bch2_bkey_pack_pos_lossy

[syzbot <syzbot+e8bd437eb38c35c5f35a@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    c2ee9f594da8 KVM: selftests: Fix build on on non-x86 archi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1051ca5f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=fc6f8ce8c5369043
dashboard link: https://syzkaller.appspot.com/bug?extid=e8bd437eb38c35c5f35a
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=16e1a640580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15344287980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-c2ee9f59.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8a3541902b13/vmlinux-c2ee9f59.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a00efacc2604/bzImage-c2ee9f59.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/e27719dd0715/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e8bd437eb38c35c5f35a@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:130!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5096 Comm: syz-executor440 Not tainted 6.12.0-rc4-syzkaller-00047-gc2ee9f594da8 #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:pack_state_finish fs/bcachefs/bkey.c:130 [inline]
RIP: 0010:bch2_bkey_pack_pos_lossy+0x1956/0x1990 fs/bcachefs/bkey.c:525
Code: fd 90 0f 0b e8 5b b8 83 fd 90 0f 0b e8 53 b8 83 fd 90 0f 0b e8 4b b8 83 fd 90 0f 0b e8 43 b8 83 fd 90 0f 0b e8 3b b8 83 fd 90 <0f> 0b e8 33 47 b5 07 e8 2e b8 83 fd 90 0f 0b e8 26 b8 83 fd 90 0f
RSP: 0018:ffffc90002c3dd20 EFLAGS: 00010293
RAX: ffffffff84111fa5 RBX: ffffc90802c3e0b8 RCX: ffff88801fa9a440
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90002c3df58 R08: ffffffff84110ea6 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff8880408320c0 R14: 0000000000000000 R15: ffffc90002c3e0c0
FS:  0000555561411380(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055cccf015d88 CR3: 0000000040a32000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bch2_btree_node_iter_init+0x894/0x4280 fs/bcachefs/bset.c:1313
 __btree_path_level_init fs/bcachefs/btree_iter.c:615 [inline]
 bch2_btree_path_level_init+0x4d2/0x9f0 fs/bcachefs/btree_iter.c:635
 btree_path_lock_root fs/bcachefs/btree_iter.c:769 [inline]
 bch2_btree_path_traverse_one+0x10de/0x2940 fs/bcachefs/btree_iter.c:1170
 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:247 [inline]
 __bch2_btree_iter_peek fs/bcachefs/btree_iter.c:2197 [inline]
 bch2_btree_iter_peek_upto+0xb58/0x70e0 fs/bcachefs/btree_iter.c:2297
 bch2_btree_iter_peek_upto_type fs/bcachefs/btree_iter.h:685 [inline]
 bch2_gc_btree fs/bcachefs/btree_gc.c:670 [inline]
 bch2_gc_btrees fs/bcachefs/btree_gc.c:729 [inline]
 bch2_check_allocations+0x1a8b/0x6e80 fs/bcachefs/btree_gc.c:1123
 bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:185
 bch2_run_recovery_passes+0x387/0x870 fs/bcachefs/recovery_passes.c:232
 bch2_fs_recovery+0x25cc/0x39c0 fs/bcachefs/recovery.c:862
 bch2_fs_start+0x356/0x5b0 fs/bcachefs/super.c:1036
 bch2_fs_get_tree+0xd68/0x1710 fs/bcachefs/fs.c:2174
 vfs_get_tree+0x90/0x2b0 fs/super.c:1800
 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: 0033:0x7f354cc85c3a
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:00007fff33d28828 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fff33d28840 RCX: 00007f354cc85c3a
RDX: 00000000200058c0 RSI: 0000000020005900 RDI: 00007fff33d28840
RBP: 0000000000000004 R08: 00007fff33d28880 R09: 0000000000005932
R10: 0000000000010000 R11: 0000000000000282 R12: 0000000000010000
R13: 00007fff33d28880 R14: 0000000000000003 R15: 0000000001000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:pack_state_finish fs/bcachefs/bkey.c:130 [inline]
RIP: 0010:bch2_bkey_pack_pos_lossy+0x1956/0x1990 fs/bcachefs/bkey.c:525
Code: fd 90 0f 0b e8 5b b8 83 fd 90 0f 0b e8 53 b8 83 fd 90 0f 0b e8 4b b8 83 fd 90 0f 0b e8 43 b8 83 fd 90 0f 0b e8 3b b8 83 fd 90 <0f> 0b e8 33 47 b5 07 e8 2e b8 83 fd 90 0f 0b e8 26 b8 83 fd 90 0f
RSP: 0018:ffffc90002c3dd20 EFLAGS: 00010293
RAX: ffffffff84111fa5 RBX: ffffc90802c3e0b8 RCX: ffff88801fa9a440
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90002c3df58 R08: ffffffff84110ea6 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff8880408320c0 R14: 0000000000000000 R15: ffffc90002c3e0c0
FS:  0000555561411380(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055cccf015d88 CR3: 0000000040a32000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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