From: ZhangPeng zhangpeng362@huawei.com
[ Upstream commit b8c44949044e5f7f864525fdffe8e95135ce9ce5 ]
Syzbot reported a OOB read bug:
BUG: KASAN: slab-out-of-bounds in indx_insert_into_buffer+0xaa3/0x13b0 fs/ntfs3/index.c:1755 Read of size 17168 at addr ffff8880255e06c0 by task syz-executor308/3630
Call Trace: <TASK> memmove+0x25/0x60 mm/kasan/shadow.c:54 indx_insert_into_buffer+0xaa3/0x13b0 fs/ntfs3/index.c:1755 indx_insert_entry+0x446/0x6b0 fs/ntfs3/index.c:1863 ntfs_create_inode+0x1d3f/0x35c0 fs/ntfs3/inode.c:1548 ntfs_create+0x3e/0x60 fs/ntfs3/namei.c:100 lookup_open fs/namei.c:3413 [inline]
If the member struct INDEX_BUFFER *index of struct indx_node is incorrect, that is, the value of __le32 used is greater than the value of __le32 total in struct INDEX_HDR. Therefore, OOB read occurs when memmove is called in indx_insert_into_buffer(). Fix this by adding a check in hdr_find_e().
Fixes: 82cae269cfa9 ("fs/ntfs3: Add initialization of super block") Reported-by: syzbot+d882d57193079e379309@syzkaller.appspotmail.com Signed-off-by: ZhangPeng zhangpeng362@huawei.com Signed-off-by: Konstantin Komarov almaz.alexandrovich@paragon-software.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ntfs3/index.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c index c27b4fe575136..bdc931990d2cc 100644 --- a/fs/ntfs3/index.c +++ b/fs/ntfs3/index.c @@ -679,9 +679,13 @@ static struct NTFS_DE *hdr_find_e(const struct ntfs_index *indx, u32 e_size, e_key_len; u32 end = le32_to_cpu(hdr->used); u32 off = le32_to_cpu(hdr->de_off); + u32 total = le32_to_cpu(hdr->total); u16 offs[128];
fill_table: + if (end > total) + return NULL; + if (off + sizeof(struct NTFS_DE) > end) return NULL;