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authorJens Axboe <jaxboe@fusionio.com>2010-10-23 22:40:26 +0400
committerJens Axboe <jaxboe@fusionio.com>2010-10-23 22:40:26 +0400
commit7ad58c028652753814054f4e3ac58f925e7343f4 (patch)
tree2e3bc1c5e3c98078b970483cd49a49d7c1ae0dcf
parent7f3883962870dd28b5f2322ac44a9d03640ef448 (diff)
downloadlinux-7ad58c028652753814054f4e3ac58f925e7343f4.tar.xz
block: fix use-after-free bug in blk throttle code
blk_throtl_exit() frees the throttle data hanging off the queue in blk_cleanup_queue(), but blk_put_queue() will indirectly dereference this data when calling blk_sync_queue() which in turns calls throtl_shutdown_timer_wq(). Fix this by moving the freeing of the throttle data to when the queue is truly being released, and post the call to blk_sync_queue(). Reported-by: Ingo Molnar <mingo@elte.hu> Tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
-rw-r--r--block/blk-core.c2
-rw-r--r--block/blk-sysfs.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 45141469e89e..51efd835d4cf 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -462,8 +462,6 @@ void blk_cleanup_queue(struct request_queue *q)
if (q->elevator)
elevator_exit(q->elevator);
- blk_throtl_exit(q);
-
blk_put_queue(q);
}
EXPORT_SYMBOL(blk_cleanup_queue);
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index da8a8a40cd4c..013457f47fdc 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -471,6 +471,8 @@ static void blk_release_queue(struct kobject *kobj)
blk_sync_queue(q);
+ blk_throtl_exit(q);
+
if (rl->rq_pool)
mempool_destroy(rl->rq_pool);