diff options
| author | Hawkins Jiawei <yin31149@gmail.com> | 2022-09-01 00:09:38 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-11-25 17:40:30 +0100 |
| commit | 45683723f6b53e39e8a4cec0894e61fd6ec71989 (patch) | |
| tree | 945d454d6663f9ba989d38f94a0768008077e804 | |
| parent | 4301aa833a734257ad3715f607cbde17402eda94 (diff) | |
ntfs: check overflow when iterating ATTR_RECORDs
commit 63095f4f3af59322bea984a6ae44337439348fe0 upstream.
Kernel iterates over ATTR_RECORDs in mft record in ntfs_attr_find().
Because the ATTR_RECORDs are next to each other, kernel can get the next
ATTR_RECORD from end address of current ATTR_RECORD, through current
ATTR_RECORD length field.
The problem is that during iteration, when kernel calculates the end
address of current ATTR_RECORD, kernel may trigger an integer overflow bug
in executing `a = (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length))`. This
may wrap, leading to a forever iteration on 32bit systems.
This patch solves it by adding some checks on calculating end address
of current ATTR_RECORD during iteration.
Link: https://lkml.kernel.org/r/20220831160935.3409-4-yin31149@gmail.com
Link: https://lore.kernel.org/all/20220827105842.GM2030@kadam/
Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Anton Altaparmakov <anton@tuxera.com>
Cc: chenxiaosong (A) <chenxiaosong2@huawei.com>
Cc: syzkaller-bugs <syzkaller-bugs@googlegroups.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/ntfs/attrib.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c index 122a9b45b350..0a7efbe2adb3 100644 --- a/fs/ntfs/attrib.c +++ b/fs/ntfs/attrib.c @@ -631,6 +631,14 @@ static int ntfs_attr_find(const ATTR_TYPE type, const ntfschar *name, return -ENOENT; if (unlikely(!a->length)) break; + + /* check whether ATTR_RECORD's length wrap */ + if ((u8 *)a + le32_to_cpu(a->length) < (u8 *)a) + break; + /* check whether ATTR_RECORD's length is within bounds */ + if ((u8 *)a + le32_to_cpu(a->length) > mrec_end) + break; + if (a->type != type) continue; /* |