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From: Carlos Maiolino <cmaiolino@redhat.com>
To: xfs@oss.sgi.com
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Subject: [PATCH] Fix possible memory corruption in xfs_readlink
Date: Tue, 18 Oct 2011 02:18:58 -0200	[thread overview]
Message-ID: <1318911538-9174-1-git-send-email-cmaiolino@redhat.com> (raw)

Fixes a possible memory corruption when the link is larger than
MAXPATHLEN and XFS_DEBUG is not enabled. This also remove the
S_ISLNK assert, since the inode mode is checked previously in
xfs_readlink_by_handle() and via VFS.

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 fs/xfs/xfs_vnodeops.c |   11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 51fc429..c3288be 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -123,13 +123,18 @@ xfs_readlink(
 
 	xfs_ilock(ip, XFS_ILOCK_SHARED);
 
-	ASSERT(S_ISLNK(ip->i_d.di_mode));
-	ASSERT(ip->i_d.di_size <= MAXPATHLEN);
-
 	pathlen = ip->i_d.di_size;
 	if (!pathlen)
 		goto out;
 
+	if (pathlen > MAXPATHLEN) {
+		xfs_alert(mp, "%s: inode (%llu) symlink length (%d) too long",
+			 __func__, (unsigned long long)ip->i_ino, pathlen);
+		ASSERT(0);
+		return XFS_ERROR(EFSCORRUPTED);
+	}
+
+
 	if (ip->i_df.if_flags & XFS_IFINLINE) {
 		memcpy(link, ip->i_df.if_u1.if_data, pathlen);
 		link[pathlen] = '\0';
-- 
1.7.6.2

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             reply	other threads:[~2011-10-18  1:20 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-10-18  4:18 Carlos Maiolino [this message]
2011-10-18  6:52 ` [PATCH] Fix possible memory corruption in xfs_readlink Christoph Hellwig
2011-10-18 13:59 ` Alex Elder
2011-10-18 14:25 ` Eric Sandeen
  -- strict thread matches above, loose matches on Subject: below --
2011-11-01 14:14 Ben Hutchings
2011-11-02 17:52 ` Alex Elder
2011-11-02 19:45   ` Christoph Hellwig
2011-11-02 20:22     ` Alex Elder
2011-10-17 21:05 Carlos Maiolino
2011-10-17 22:39 ` Alex Elder
2011-10-17 22:43 ` Dave Chinner
2011-10-18  1:28   ` Carlos Maiolino
2011-10-17 15:30 Carlos Maiolino
2011-10-17 14:00 ` Christoph Hellwig
2011-10-17 17:24   ` Eric Sandeen

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