loop0: detected capacity change from 0 to 32768
bcachefs (loop0): starting version 1.7: mi_btree_bitmap opts=metadata_checksum=none,data_checksum=none,compression=lz4,fsck,fix_errors=ask,norecovery,recovery_pass_last=reconstruct_snapshots,nojournal_transaction_names,reconstruct_alloc
bcachefs (loop0): recovering from clean shutdown, journal seq 10
bcachefs (loop0): Doing compatible version upgrade from 1.7: mi_btree_bitmap to 1.25: extent_flags
  running recovery passes: check_allocations,check_extents_to_backpointers,check_inodes
bcachefs (loop0): invalid btree id 251 (max 63), fix?
bcachefs (loop0): dropping and reconstructing all alloc info
bcachefs (loop0): running explicit recovery pass check_topology (2), currently at recovery_pass_empty (0)
bcachefs (loop0): bcachefs (loop0): error validating btree node on loop0 at btree xattrs level 0/0
  u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 2285c34bed0abe32 written 16 min_key POS_MIN durability: 1 ptr: 0:31:0 gen 0
  node offset 0/16 bset u64s 0: incorrect max key U64_MAX:18374686479671623680:50331647, btree topology error: 
bcachefs (loop0): flagging btree xattrs lost data
bcachefs (loop0): running explicit recovery pass check_backpointers_to_extents (16), currently at recovery_pass_empty (0)
bcachefs (loop0): running explicit recovery pass scan_for_btree_nodes (1), currently at recovery_pass_empty (0)
bcachefs (loop0): error reading btree root btree=xattrs level=0: btree_node_read_error, fixing
------------[ cut here ]------------
UBSAN: shift-out-of-bounds in fs/bcachefs/btree_cache.c:218:18
shift exponent 251 is too large for 64-bit type 'unsigned long long'
CPU: 0 UID: 0 PID: 5326 Comm: syz.0.0 Not tainted 6.14.0-syzkaller-12245-g91e5bfe317d8 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_shift_out_of_bounds+0x3c8/0x420 lib/ubsan.c:492
 __btree_node_pinned fs/bcachefs/btree_cache.c:218 [inline]
 __bch2_btree_node_hash_insert+0x1b32/0x1ba0 fs/bcachefs/btree_cache.c:294
 bch2_btree_node_hash_insert+0x7e/0xc0 fs/bcachefs/btree_cache.c:309
 __bch2_btree_root_read fs/bcachefs/btree_io.c:1790 [inline]
 bch2_btree_root_read+0x605/0x7e0 fs/bcachefs/btree_io.c:1818
 read_btree_roots+0x3d7/0xa80 fs/bcachefs/recovery.c:581
 bch2_fs_recovery+0x28e4/0x3e20 fs/bcachefs/recovery.c:928
 bch2_fs_start+0x2fb/0x610 fs/bcachefs/super.c:1060
 bch2_fs_get_tree+0x113e/0x18f0 fs/bcachefs/fs.c:2253
 vfs_get_tree+0x90/0x2b0 fs/super.c:1759
 do_new_mount+0x2cf/0xb70 fs/namespace.c:3878
 do_mount fs/namespace.c:4218 [inline]
 __do_sys_mount fs/namespace.c:4429 [inline]
 __se_sys_mount+0x38c/0x400 fs/namespace.c:4406
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd59618e90a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd597081e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd597081ef0 RCX: 00007fd59618e90a
RDX: 0000200000000180 RSI: 0000200000000540 RDI: 00007fd597081eb0
RBP: 0000200000000180 R08: 00007fd597081ef0 R09: 0000000000800000
R10: 0000000000800000 R11: 0000000000000246 R12: 0000200000000540
R13: 00007fd597081eb0 R14: 000000000000596a R15: 0000200000000000
 </TASK>
---[ end trace ]---