diff options
| author | Edward Adam Davis <eadavis@qq.com> | 2026-04-17 07:44:02 +0800 |
|---|---|---|
| committer | Viacheslav Dubeyko <slava@dubeyko.com> | 2026-04-27 15:27:41 -0700 |
| commit | 3f95e2661574ff13f099dd13456751933c280628 (patch) | |
| tree | ed004b2cb1790b2ae9ca0264c3683c86f56268fe /include/linux | |
| parent | 5f63ac80aef2ee6bb58eab62e98c264774872da6 (diff) | |
hfsplus: Add a sanity check for btree node size
Syzbot reported an uninit-value bug in [1] with a corrupted HFS+ image,
during the file system mounting process, specifically while loading the
catalog, a corrupted node_size value of 1 caused the rec_off argument
passed to hfs_bnode_read_u16() (within hfs_bnode_find()) to be excessively
large. Consequently, the function failed to return a valid value to
initialize the off variable, triggering the bug [1].
Every node starts from BTree node descriptor: struct hfs_bnode_desc.
So, the size of node cannot be lesser than that. However, technical
specification declares that: "The node size (which is expressed in bytes)
must be power of two, from 512 through 32,768, inclusive." Add a check
for btree node size base on technical specification.
[1]
BUG: KMSAN: uninit-value in hfsplus_bnode_find+0x141c/0x1600 fs/hfsplus/bnode.c:584
hfsplus_bnode_find+0x141c/0x1600 fs/hfsplus/bnode.c:584
hfsplus_btree_open+0x169a/0x1e40 fs/hfsplus/btree.c:382
hfsplus_fill_super+0x111f/0x2770 fs/hfsplus/super.c:553
get_tree_bdev_flags+0x6e6/0x920 fs/super.c:1694
get_tree_bdev+0x38/0x50 fs/super.c:1717
hfsplus_get_tree+0x35/0x40 fs/hfsplus/super.c:709
vfs_get_tree+0xb3/0x5d0 fs/super.c:1754
fc_mount fs/namespace.c:1193 [inline]
Fixes: 8ad2c6a36ac4 ("hfsplus: validate b-tree node 0 bitmap at mount time")
Reported-by: syzbot+217eb327242d08197efb@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=217eb327242d08197efb
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Reviewed-by: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
Link: https://lore.kernel.org/r/tencent_5ED373437A697F83A4A446B771577626CD05@qq.com
Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/hfs_common.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/hfs_common.h b/include/linux/hfs_common.h index 07dfc39630ab..45fb4c9ff9f5 100644 --- a/include/linux/hfs_common.h +++ b/include/linux/hfs_common.h @@ -513,6 +513,7 @@ struct hfs_btree_header_rec { /* HFS+ BTree misc info */ #define HFSPLUS_TREE_HEAD 0 #define HFSPLUS_NODE_MXSZ 32768 +#define HFSPLUS_NODE_MINSZ 512 #define HFSPLUS_ATTR_TREE_NODE_SIZE 8192 #define HFSPLUS_BTREE_HDR_NODE_RECS_COUNT 3 #define HFSPLUS_BTREE_HDR_MAP_REC_INDEX 2 /* Map (bitmap) record in Header node */ |