Re: [PATCH] blk-mq: fix double-free in error path
From: Jens Axboe
Date: Wed Feb 11 2015 - 11:43:53 EST
On 02/11/2015 09:32 AM, Tony Battersby wrote:
If the allocation of bt->bs fails, then bt->map can be freed twice, once
in blk_mq_init_bitmap_tags() -> bt_alloc(), and once in
blk_mq_init_bitmap_tags() -> bt_free(). Fix by setting the pointer to
NULL after the first free.
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Tony Battersby <tonyb@xxxxxxxxxxxxxxx>
---
For inclusion in kernel 3.20.
--- linux-3.19.0/block/blk-mq-tag.c.orig 2015-02-08 21:54:22.000000000 -0500
+++ linux-3.19.0/block/blk-mq-tag.c 2015-02-10 09:42:38.000000000 -0500
@@ -509,6 +509,7 @@ static int bt_alloc(struct blk_mq_bitmap
bt->bs = kzalloc(BT_WAIT_QUEUES * sizeof(*bt->bs), GFP_KERNEL);
if (!bt->bs) {
kfree(bt->map);
+ bt->map = NULL;
return -ENOMEM;
}
Thanks Tony, applied.
--
Jens Axboe
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