From 135949c10b4f97eaf9da90535e18c6a2a0e2993a Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <mpatocka@redhat.com>
Date: Fri, 22 Nov 2013 19:52:06 -0500
Subject: [PATCH] dm table: fail dm_table_create on dm_round_up overflow
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 <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/md/dm-table.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 9e3a045eb7a2..bd88d3dade1e 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -215,6 +215,11 @@ int dm_table_create(struct dm_table **result, fmode_t mode,
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);
return -ENOMEM;
--
2.34.1