From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Mikulas Patocka" , "Mike Snitzer" Date: Sun, 29 Dec 2013 03:08:44 +0100 Message-ID: Subject: [PATCH 3.2 132/185] dm table: fail dm_table_create on dm_round_up overflow In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.2.54-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Mikulas Patocka commit 5b2d06576c5410c10d95adfd5c4d8b24de861d87 upstream. The dm_round_up function may overflow to zero. In this case, dm_table_create() must fail rather than go on to allocate an empty array with alloc_targets(). This fixes a possible memory corruption that could be caused by passing too large a number in "param->target_count". Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Ben Hutchings --- drivers/md/dm-table.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -215,6 +215,11 @@ int dm_table_create(struct dm_table **re num_targets = dm_round_up(num_targets, KEYS_PER_NODE); + if (!num_targets) { + kfree(t); + return -ENOMEM; + } + if (alloc_targets(t, num_targets)) { kfree(t); t = NULL;