blob: 771f4396e5d57918bd5b44563dc8dee24e0c7a16 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
|
From f4020438fab05364018c91f7e02ebdd192085933 Mon Sep 17 00:00:00 2001
From: Eric Sandeen <sandeen@redhat.com>
Date: Wed, 26 Aug 2020 14:11:58 -0700
Subject: [PATCH] xfs: fix boundary test in xfs_attr_shortform_verify
The boundary test for the fixed-offset parts of xfs_attr_sf_entry in
xfs_attr_shortform_verify is off by one, because the variable array
at the end is defined as nameval[1] not nameval[].
Hence we need to subtract 1 from the calculation.
This can be shown by:
# touch file
# setfattr -n root.a file
and verifications will fail when it's written to disk.
This only matters for a last attribute which has a single-byte name
and no value, otherwise the combination of namelen & valuelen will
push endp further out and this test won't fail.
Fixes: 1e1bbd8e7ee06 ("xfs: create structure verifier function for shortform xattrs")
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/libxfs/xfs_attr_leaf.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c
index 8623c815164a..383b08f2ac61 100644
--- a/fs/xfs/libxfs/xfs_attr_leaf.c
+++ b/fs/xfs/libxfs/xfs_attr_leaf.c
@@ -1036,8 +1036,10 @@ xfs_attr_shortform_verify(
* struct xfs_attr_sf_entry has a variable length.
* Check the fixed-offset parts of the structure are
* within the data buffer.
+ * xfs_attr_sf_entry is defined with a 1-byte variable
+ * array at the end, so we must subtract that off.
*/
- if (((char *)sfep + sizeof(*sfep)) >= endp)
+ if (((char *)sfep + sizeof(*sfep) - 1) >= endp)
return __this_address;
/* Don't allow names with known bad length. */
--
2.26.2
|
