diff mbox

[lts-backport-raring,CVE-2013-6382] xfs: underflow bug in xfs_attrlist_by_handle()

Message ID 1392902924-14377-4-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques Feb. 20, 2014, 1:28 p.m. UTC 
From: Dan Carpenter <dan.carpenter@oracle.com>

CVE-2013-6382

BugLink: http://bugs.launchpad.net/bugs/1256091

If we allocate less than sizeof(struct attrlist) then we end up
corrupting memory or doing a ZERO_PTR_SIZE dereference.

This can only be triggered with CAP_SYS_ADMIN.

Reported-by: Nico Golde <nico@ngolde.de>
Reported-by: Fabian Yamaguchi <fabs@goesec.de>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
(cherry picked from commit 31978b5cc66b8ba8a7e8eef60b12395d41b7b890)
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 fs/xfs/xfs_ioctl.c   | 3 ++-
 fs/xfs/xfs_ioctl32.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 2fe3eb3..cdaef2d 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -409,7 +409,8 @@  xfs_attrlist_by_handle(
 		return -XFS_ERROR(EPERM);
 	if (copy_from_user(&al_hreq, arg, sizeof(xfs_fsop_attrlist_handlereq_t)))
 		return -XFS_ERROR(EFAULT);
-	if (al_hreq.buflen > XATTR_LIST_MAX)
+	if (al_hreq.buflen < sizeof(struct attrlist) ||
+	    al_hreq.buflen > XATTR_LIST_MAX)
 		return -XFS_ERROR(EINVAL);
 
 	/*
diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c
index 1244274..b8bfe2a 100644
--- a/fs/xfs/xfs_ioctl32.c
+++ b/fs/xfs/xfs_ioctl32.c
@@ -359,7 +359,8 @@  xfs_compat_attrlist_by_handle(
 	if (copy_from_user(&al_hreq, arg,
 			   sizeof(compat_xfs_fsop_attrlist_handlereq_t)))
 		return -XFS_ERROR(EFAULT);
-	if (al_hreq.buflen > XATTR_LIST_MAX)
+	if (al_hreq.buflen < sizeof(struct attrlist) ||
+	    al_hreq.buflen > XATTR_LIST_MAX)
 		return -XFS_ERROR(EINVAL);
 
 	/*