Zero length message leads to an empty skb loop0: detected capacity change from 0 to 32768 bcachefs (loop0): Using encoding defined by superblock: utf8-12.1.0 bcachefs (loop0): starting version 1.7: mi_btree_bitmap opts=metadata_checksum=none,data_checksum=none,compression=lz4,nojournal_transaction_names allowing incompatible features above 0.0: (unknown version) features: lz4,new_siphash,inline_data,new_extent_overwrite,btree_ptr_v2,new_varint,journal_no_flush,alloc_v2,extents_across_btree_nodes bcachefs (loop0): recovering from clean shutdown, journal seq 10 bcachefs (loop0): Version upgrade required: Version upgrade from 0.24: unwritten_extents to 1.7: mi_btree_bitmap incomplete Doing incompatible version upgrade from 0.24: unwritten_extents to 1.28: inode_has_case_insensitive running recovery passes: check_allocations,check_alloc_info,check_lrus,check_btree_backpointers,check_backpointers_to_extents,check_extents_to_backpointers,check_alloc_to_lru_refs,bucket_gens_init,check_snapshot_trees,check_snapshots,check_subvols,check_subvol_children,delete_dead_snapshots,check_inodes,check_extents,check_indirect_extents,check_dirents,check_xattrs,check_root,check_unreachable_inodes,check_subvolume_structure,check_directory_structure,check_nlinks,check_rebalance_work,set_fs_needs_rebalance bcachefs (loop0): invalid bkey in btree_node btree=alloc level=0: u64s 12 type alloc_v4 0:28:0 len 0 ver 0: gen 0 oldest_gen 0 data_type btree journal_seq_nonempty 6 journal_seq_empty 0 need_discard 1 need_inc_gen 1 dirty_sectors 0 stripe_sectors 0 cached_sectors 0 stripe 0 stripe_redundancy 0 io_time[READ] 1 io_time[WRITE] 768 fragmentation 0 bp_start 8 invalid data type (got 3 should be 9), deleting bcachefs (loop0): btree node read error at btree alloc level 0/0 u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq ac62141f8dc7e261 written 65048 min_key R 0:0:255 durability: 1 ptr: 0:26:0 gen 0 node offset 8/65048 bset u64s 375 bset byte offset 184: keys out of order: u64s 11 type alloc_v4 0:32:0 len 0 ver 0 > u64s 11 type alloc_v4 0:2:0 len 0 ver 0 loop0 node offset 24/65048: btree node data missing: expected 65048 sectors, found 24 repair success (rewriting node) bcachefs (loop0): accounting_read... done bcachefs (loop0): alloc_read... ------------[ cut here ]------------ kernel BUG at fs/bcachefs/btree_iter.c:633! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5319 Comm: syz.0.0 Not tainted 6.15.0-syzkaller-10820-gcd2e103d57e5 #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 RIP: 0010:bch2_btree_path_level_init+0x9f9/0xa20 fs/bcachefs/btree_iter.c:633 Code: 91 fb ff ff e8 98 d9 9e fd 90 0f 0b e8 90 d9 9e fd 90 0f 0b e8 88 d9 9e fd 90 0f 0b e8 80 d9 9e fd 90 0f 0b e8 78 d9 9e fd 90 <0f> 0b e8 70 d9 9e fd 90 0f 0b e8 68 d9 9e fd 90 0f 0b e8 60 d9 9e RSP: 0018:ffffc9000d686988 EFLAGS: 00010287 RAX: ffffffff84216168 RBX: ffff888052fa0268 RCX: 0000000000100000 RDX: ffffc9000e7ab000 RSI: 00000000000516f4 RDI: 00000000000516f5 RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff52001ad0d28 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00000000000000ff FS: 00007f9fee5d46c0(0000) GS:ffff88808d25f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b06113c880 CR3: 0000000043775000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: btree_path_lock_root fs/bcachefs/btree_iter.c:787 [inline] bch2_btree_path_traverse_one+0xe34/0x2460 fs/bcachefs/btree_iter.c:1203 bch2_btree_path_traverse fs/bcachefs/btree_iter.h:250 [inline] __bch2_btree_iter_peek fs/bcachefs/btree_iter.c:2262 [inline] bch2_btree_iter_peek_max+0x988/0x5290 fs/bcachefs/btree_iter.c:2365 bch2_btree_iter_peek_max_type fs/bcachefs/btree_iter.h:743 [inline] bch2_alloc_read+0xe05/0x1d40 fs/bcachefs/alloc_background.c:643 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:415 [inline] __bch2_run_recovery_passes+0x385/0x10b0 fs/bcachefs/recovery_passes.c:470 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:541 bch2_fs_recovery+0x2617/0x3970 fs/bcachefs/recovery.c:974 bch2_fs_start+0xa43/0xd30 fs/bcachefs/super.c:1206 bch2_fs_get_tree+0xbfc/0x15f0 fs/bcachefs/fs.c:2479 vfs_get_tree+0x8f/0x2b0 fs/super.c:1802 do_new_mount+0x24a/0xa40 fs/namespace.c:3856 do_mount fs/namespace.c:4193 [inline] __do_sys_mount fs/namespace.c:4404 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9fed79010a 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:00007f9fee5d3e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f9fee5d3ef0 RCX: 00007f9fed79010a RDX: 00002000000058c0 RSI: 0000200000005900 RDI: 00007f9fee5d3eb0 RBP: 00002000000058c0 R08: 00007f9fee5d3ef0 R09: 000000000001000c R10: 000000000001000c R11: 0000000000000246 R12: 0000200000005900 R13: 00007f9fee5d3eb0 R14: 0000000000005903 R15: 0000200000000480 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:bch2_btree_path_level_init+0x9f9/0xa20 fs/bcachefs/btree_iter.c:633 Code: 91 fb ff ff e8 98 d9 9e fd 90 0f 0b e8 90 d9 9e fd 90 0f 0b e8 88 d9 9e fd 90 0f 0b e8 80 d9 9e fd 90 0f 0b e8 78 d9 9e fd 90 <0f> 0b e8 70 d9 9e fd 90 0f 0b e8 68 d9 9e fd 90 0f 0b e8 60 d9 9e RSP: 0018:ffffc9000d686988 EFLAGS: 00010287 RAX: ffffffff84216168 RBX: ffff888052fa0268 RCX: 0000000000100000 RDX: ffffc9000e7ab000 RSI: 00000000000516f4 RDI: 00000000000516f5 RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff52001ad0d28 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00000000000000ff FS: 00007f9fee5d46c0(0000) GS:ffff88808d25f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b06113c880 CR3: 0000000043775000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400