[PATCH] xfs: fix acl count validation in xfs_acl_from_disk()

From: Xi Wang
Date: Mon Dec 12 2011 - 16:57:59 EST


Commit fa8b18ed didn't prevent the integer overflow and possible
memory corruption. "count" can go negative and bypass the check.

Signed-off-by: Xi Wang <xi.wang@xxxxxxxxx>
---
fs/xfs/xfs_acl.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c
index 76e4266..ac702a6 100644
--- a/fs/xfs/xfs_acl.c
+++ b/fs/xfs/xfs_acl.c
@@ -39,7 +39,7 @@ xfs_acl_from_disk(struct xfs_acl *aclp)
struct posix_acl_entry *acl_e;
struct posix_acl *acl;
struct xfs_acl_entry *ace;
- int count, i;
+ unsigned int count, i;

count = be32_to_cpu(aclp->acl_cnt);
if (count > XFS_ACL_MAX_ENTRIES)
--
1.7.5.4

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