[PATCH 1/1] xfs: check for possible overflow in xfs_ioc_trim

Tomas Racek
2012-07-30T08:14:20Z

If range.start argument was between ULLONG_MAX - BBSIZE and ULLONG_MAX,
BTOBB macro resulted in overflow which caused start to be set to 0.
Now, invalid argument error is returned instead.

Signed-off-by: Tomas Racek <tracek@redhat.com>
---
fs/xfs/xfs_discard.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/fs/xfs/xfs_discard.c b/fs/xfs/xfs_discard.c
index f9c3fe3..0ef7dd4 100644
--- a/fs/xfs/xfs_discard.c
+++ b/fs/xfs/xfs_discard.c
@@ -179,6 +179,10 @@ xfs_ioc_trim(
* used by the fstrim application. In the end it really doesn't
* matter as trimming blocks is an advisory interface.
*/
+
+ if (range.start > ULLONG_MAX - BBSIZE)
+ return -XFS_ERROR(EINVAL);
+
start = BTOBB(range.start);
end = start + BTOBBT(range.len) - 1;
minlen = BTOBB(max_t(u64, granularity, range.minlen));
--
1.7.7.6