| Message ID | 20190827013619.13803-1-wqu@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: tree-checker: Reject unknown tree owner 0 | expand |
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c index 3ce447eb591c..406ecdb38a53 100644 --- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -973,6 +973,12 @@ static int check_leaf(struct extent_buffer *leaf, bool check_item_data) owner); return -EUCLEAN; } + /* Unknown tree */ + if (owner == 0) { + generic_err(leaf, 0, + "invalid owner, root 0 is not defined"); + return -EUCLEAN; + } return 0; }
[BUG] With crafted image, btrfs will panic at btree operations: kernel BUG at fs/btrfs/ctree.c:3894! invalid opcode: 0000 [#1] SMP PTI CPU: 0 PID: 1138 Comm: btrfs-transacti Not tainted 5.0.0-rc8+ #9 RIP: 0010:__push_leaf_left+0x6b6/0x6e0 Code: 00 00 48 98 48 8d 04 80 48 8d 74 80 65 e8 42 5a 04 00 48 8b bd 78 ff ff ff 8b bf 90 d0 00 00 89 7d 98 83 ef 65 e9 06 ff ff ff <0f> 0b 0f 0b 48 8b 85 78 ff ff ff 8b 90 90 d0 00 00 e9 eb fe ff ff RSP: 0018:ffffc0bd4128b990 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffa0a4ab8f0e38 RCX: 0000000000000000 RDX: ffffa0a280000000 RSI: 0000000000000000 RDI: ffffa0a4b3814000 RBP: ffffc0bd4128ba38 R08: 0000000000001000 R09: ffffc0bd4128b948 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000240 R13: ffffa0a4b556fb60 R14: ffffa0a4ab8f0af0 R15: ffffa0a4ab8f0af0 FS: 0000000000000000(0000) GS:ffffa0a4b7a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2461c80020 CR3: 000000022b32a006 CR4: 00000000000206f0 Call Trace: ? _cond_resched+0x1a/0x50 push_leaf_left+0x179/0x190 btrfs_del_items+0x316/0x470 btrfs_del_csums+0x215/0x3a0 __btrfs_free_extent.isra.72+0x5a7/0xbe0 __btrfs_run_delayed_refs+0x539/0x1120 btrfs_run_delayed_refs+0xdb/0x1b0 btrfs_commit_transaction+0x52/0x950 ? start_transaction+0x94/0x450 transaction_kthread+0x163/0x190 kthread+0x105/0x140 ? btrfs_cleanup_transaction+0x560/0x560 ? kthread_destroy_worker+0x50/0x50 ret_from_fork+0x35/0x40 Modules linked in: ---[ end trace c2425e6e89b5558f ]--- [CAUSE] The offending csum tree looks like this: checksum tree key (CSUM_TREE ROOT_ITEM 0) node 29741056 level 1 items 14 free 107 generation 19 owner CSUM_TREE ... key (EXTENT_CSUM EXTENT_CSUM 85975040) block 29630464 gen 17 key (EXTENT_CSUM EXTENT_CSUM 89911296) block 29642752 gen 17 <<< key (EXTENT_CSUM EXTENT_CSUM 92274688) block 29646848 gen 17 ... leaf 29630464 items 6 free space 1 generation 17 owner CSUM_TREE item 0 key (EXTENT_CSUM EXTENT_CSUM 85975040) itemoff 3987 itemsize 8 range start 85975040 end 85983232 length 8192 ... leaf 29642752 items 0 free space 3995 generation 17 owner 0 ^ empty leaf invalid owner ^ leaf 29646848 items 1 free space 602 generation 17 owner CSUM_TREE item 0 key (EXTENT_CSUM EXTENT_CSUM 92274688) itemoff 627 itemsize 3368 range start 92274688 end 95723520 length 3448832 [FIX] The most obvious corruption is the owner, which is pretty easy to detect and safe to reject. The better solution is to reject empty leaf/node while reading from a parent node, but that solution has been bug-prone, so at least use the owner check to reject that fuzzed image as a workaround before root fix. Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/tree-checker.c | 6 ++++++ 1 file changed, 6 insertions(+)