Messages in this thread Patch in this message | | | From | John Garry <> | Subject | [PATCH] blk-mq-sched: Don't reference queue tagset in blk_mq_sched_tags_teardown() | Date | Fri, 22 Oct 2021 16:12:20 +0800 |
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We should not reference the queue tagset in blk_mq_sched_tags_teardown() (see function comment) for the blk-mq flags, so use the passed flags instead.
This solves a use-after-free, similarly fixed earlier (and since broken again) in commit f0c1c4d2864e ("blk-mq: fix use-after-free in blk_mq_exit_sched").
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Tested-by: Anders Roxell <anders.roxell@linaro.org> Fixes: e155b0c238b2 ("blk-mq: Use shared tags for shared sbitmap support") Signed-off-by: John Garry <john.garry@huawei.com>
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index e85b7556b096..6a9444848e3a 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -541,7 +541,7 @@ static void blk_mq_sched_tags_teardown(struct request_queue *q, unsigned int fla queue_for_each_hw_ctx(q, hctx, i) { if (hctx->sched_tags) { - if (!blk_mq_is_shared_tags(q->tag_set->flags)) + if (!blk_mq_is_shared_tags(flags)) blk_mq_free_rq_map(hctx->sched_tags); hctx->sched_tags = NULL; } -- 2.17.1
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