From 39caa731fbb5bfb5cf376a18dcc63a3a0a69ee27 Mon Sep 17 00:00:00 2001 From: Junichi Nomura Date: Wed, 14 Oct 2015 05:02:15 +0000 Subject: blk-mq: fix use-after-free in blk_mq_free_tag_set() commit f42d79ab67322e51b92dd7aa965e310c71352a64 upstream. tags is freed in blk_mq_free_rq_map() and should not be used after that. The problem doesn't manifest if CONFIG_CPUMASK_OFFSTACK is false because free_cpumask_var() is nop. tags->cpumask is allocated in blk_mq_init_tags() so it's natural to free cpumask in its counter part, blk_mq_free_tags(). Fixes: f26cdc8536ad ("blk-mq: Shared tag enhancements") Signed-off-by: Jun'ichi Nomura Cc: Keith Busch Reviewed-by: Jeff Moyer Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- block/blk-mq-tag.c | 1 + block/blk-mq.c | 4 +--- 2 files changed, 2 insertions(+), 3 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 9115c6d59948..273519894951 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -628,6 +628,7 @@ void blk_mq_free_tags(struct blk_mq_tags *tags) { bt_free(&tags->bitmap_tags); bt_free(&tags->breserved_tags); + free_cpumask_var(tags->cpumask); kfree(tags); } diff --git a/block/blk-mq.c b/block/blk-mq.c index c69902695136..4d6ff5259a61 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2263,10 +2263,8 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set) int i; for (i = 0; i < set->nr_hw_queues; i++) { - if (set->tags[i]) { + if (set->tags[i]) blk_mq_free_rq_map(set, set->tags[i], i); - free_cpumask_var(set->tags[i]->cpumask); - } } kfree(set->tags); -- cgit v1.2.3