diff options
| author | Jens Axboe <axboe@kernel.dk> | 2018-04-17 17:08:52 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-04-17 17:08:52 -0600 |
| commit | 72961c4e6082be79825265d9193272b8a1634dec (patch) | |
| tree | db6b683240483097d30a95f1de6abaff2414dd55 | |
| parent | f4560231ec42092c6662acccabb28c6cac9f5dfb (diff) | |
bfq-iosched: ensure to clear bic/bfqq pointers when preparing request
Even if we don't have an IO context attached to a request, we still
need to clear the priv[0..1] pointers, as they could be pointing
to previously used bic/bfqq structures. If we don't do so, we'll
either corrupt memory on dispatching a request, or cause an
imbalance in counters.
Inspired by a fix from Kees.
Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Reported-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Fixes: aee69d78dec0 ("block, bfq: introduce the BFQ-v0 I/O scheduler as an extra scheduler")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/bfq-iosched.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index f0ecd98509d8..771ae9730ac6 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -4934,8 +4934,16 @@ static void bfq_prepare_request(struct request *rq, struct bio *bio) bool new_queue = false; bool bfqq_already_existing = false, split = false; - if (!rq->elv.icq) + /* + * Even if we don't have an icq attached, we should still clear + * the scheduler pointers, as they might point to previously + * allocated bic/bfqq structs. + */ + if (!rq->elv.icq) { + rq->elv.priv[0] = rq->elv.priv[1] = NULL; return; + } + bic = icq_to_bic(rq->elv.icq); spin_lock_irq(&bfqd->lock); |