|
 |
a15850 |
From 4801d9a446569eb73191c8cb3b769aadcd3f0994 Mon Sep 17 00:00:00 2001
|
|
|
a15850 |
From: Julien Thierry <jthierry@redhat.com>
|
|
|
a15850 |
Date: Fri, 30 Oct 2020 09:00:20 +0000
|
|
|
a15850 |
Subject: [PATCH] [fs] xfs: fix boundary test in xfs_attr_shortform_verify
|
|
|
a15850 |
|
|
|
a15850 |
Kernels:
|
|
|
a15850 |
3.10.0-1160.el7
|
|
|
a15850 |
3.10.0-1160.2.1.el7
|
|
|
a15850 |
3.10.0-1160.2.2.el7
|
|
|
a15850 |
3.10.0-1160.6.1.el7
|
|
|
a15850 |
|
|
|
a15850 |
Changes since last build:
|
|
|
a15850 |
arches: x86_64 ppc64le
|
|
|
a15850 |
xfs_attr_leaf.o: changed function: xfs_attr_shortform_verify
|
|
|
a15850 |
---------------------------
|
|
|
a15850 |
|
|
|
a15850 |
Modifications:
|
|
|
a15850 |
None
|
|
|
a15850 |
|
|
|
a15850 |
Testing: tried the commands in the commit message before and after the
|
|
|
a15850 |
kpatch-patch. Without the kpatch-patch, the filesystem dies.
|
|
|
a15850 |
|
|
|
a15850 |
commit b2f2f4aef9d49b0b9fd349f0376f5ffe735e5823
|
|
|
a15850 |
Author: Eric Sandeen <sandeen@redhat.com>
|
|
|
a15850 |
Date: Wed Sep 9 22:17:43 2020 -0400
|
|
|
a15850 |
|
|
|
a15850 |
[fs] xfs: fix boundary test in xfs_attr_shortform_verify
|
|
|
a15850 |
|
|
|
a15850 |
Message-id: <98c52b4e-9e63-55e1-5e8e-4f8d193b3762@redhat.com>
|
|
|
a15850 |
Patchwork-id: 326026
|
|
|
a15850 |
Patchwork-instance: patchwork
|
|
|
a15850 |
O-Subject: [PATCH RHEL7.9.z] xfs: fix boundary test in xfs_attr_shortform_verify
|
|
|
a15850 |
Bugzilla: 1875317
|
|
|
a15850 |
CVE: CVE-2020-14385
|
|
|
a15850 |
RH-Acked-by: Carlos Maiolino <cmaiolino@redhat.com>
|
|
|
a15850 |
RH-Acked-by: Brian Foster <bfoster@redhat.com>
|
|
|
a15850 |
|
|
|
a15850 |
Bugzilla: 1875317
|
|
|
a15850 |
Upstream Status: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
|
|
|
a15850 |
Build Info: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=31247080
|
|
|
a15850 |
Tested: With simple reproducer in commit + xfstests
|
|
|
a15850 |
CVE: CVE-2020-14385
|
|
|
a15850 |
|
|
|
a15850 |
The boundary test for the fixed-offset parts of xfs_attr_sf_entry in
|
|
|
a15850 |
xfs_attr_shortform_verify is off by one, because the variable array
|
|
|
a15850 |
at the end is defined as nameval[1] not nameval[].
|
|
|
a15850 |
Hence we need to subtract 1 from the calculation.
|
|
|
a15850 |
|
|
|
a15850 |
This can be shown by:
|
|
|
a15850 |
|
|
|
a15850 |
# touch file
|
|
|
a15850 |
# setfattr -n root.a file
|
|
|
a15850 |
|
|
|
a15850 |
and verifications will fail when it's written to disk.
|
|
|
a15850 |
|
|
|
a15850 |
This only matters for a last attribute which has a single-byte name
|
|
|
a15850 |
and no value, otherwise the combination of namelen & valuelen will
|
|
|
a15850 |
push endp further out and this test won't fail.
|
|
|
a15850 |
|
|
|
a15850 |
Fixes: 1e1bbd8e7ee06 ("xfs: create structure verifier function for shortform xattrs")
|
|
|
a15850 |
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
|
|
|
a15850 |
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
|
|
|
a15850 |
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
|
|
|
a15850 |
Reviewed-by: Christoph Hellwig <hch@lst.de>
|
|
|
a15850 |
(cherry picked from commit f4020438fab05364018c91f7e02ebdd192085933)
|
|
|
a15850 |
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
|
|
|
a15850 |
Signed-off-by: Augusto Caringi <acaringi@redhat.com>
|
|
|
a15850 |
|
|
|
a15850 |
Signed-off-by: Julien Thierry <jthierry@redhat.com>
|
|
|
a15850 |
---
|
|
|
a15850 |
fs/xfs/libxfs/xfs_attr_leaf.c | 4 +++-
|
|
|
a15850 |
1 file changed, 3 insertions(+), 1 deletion(-)
|
|
|
a15850 |
|
|
|
a15850 |
diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c
|
|
|
a15850 |
index 2c892846929..1d2bedd4c1a 100644
|
|
|
a15850 |
--- a/fs/xfs/libxfs/xfs_attr_leaf.c
|
|
|
a15850 |
+++ b/fs/xfs/libxfs/xfs_attr_leaf.c
|
|
|
a15850 |
@@ -923,8 +923,10 @@ xfs_attr_shortform_verify(
|
|
|
a15850 |
* struct xfs_attr_sf_entry has a variable length.
|
|
|
a15850 |
* Check the fixed-offset parts of the structure are
|
|
|
a15850 |
* within the data buffer.
|
|
|
a15850 |
+ * xfs_attr_sf_entry is defined with a 1-byte variable
|
|
|
a15850 |
+ * array at the end, so we must subtract that off.
|
|
|
a15850 |
*/
|
|
|
a15850 |
- if (((char *)sfep + sizeof(*sfep)) >= endp)
|
|
|
a15850 |
+ if (((char *)sfep + sizeof(*sfep) - 1) >= endp)
|
|
|
a15850 |
return __this_address;
|
|
|
a15850 |
|
|
|
a15850 |
/* Don't allow names with known bad length. */
|
|
|
a15850 |
--
|
|
|
a15850 |
2.25.4
|
|
|
a15850 |
|