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| author |   Adrian Hunter <adrian.hunter@intel.com> | 2016-08-25 14:11:43 -0600 |
|---|---|---|
| committer |   Jens Axboe <axboe@fb.com> | 2016-08-25 14:11:43 -0600 |
| commit | 869c554808ccf7ddd25be5317073b88ceddb8507 (patch) | |
| tree | ed7f5a2112a7d00dbfa02415585bc7d1991fe824 /drivers | |
| parent | Revert "floppy: refactor open() flags handling" (diff) | |
| download | linux-dev-869c554808ccf7ddd25be5317073b88ceddb8507.tar.xz linux-dev-869c554808ccf7ddd25be5317073b88ceddb8507.zip | |
mmc: fix use-after-free of struct request
We call mmc_req_is_special() after having processed a request, but
it could be freed after that. Check that ahead of time, and use
the cached value.
Reported-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Fixes: c2df40dfb8c0 ("drivers: use req op accessor")
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mmc/card/block.c | 4 | ||||
| -rw-r--r-- | drivers/mmc/card/queue.c | 4 |
2 files changed, 5 insertions, 3 deletions
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 82503e6f04b3..2206d4477dbb 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -2151,6 +2151,7 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) struct mmc_card *card = md->queue.card; struct mmc_host *host = card->host; unsigned long flags; + bool req_is_special = mmc_req_is_special(req); if (req && !mq->mqrq_prev->req) /* claim host only for the first request */ @@ -2191,8 +2192,7 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) } out: - if ((!req && !(mq->flags & MMC_QUEUE_NEW_REQUEST)) || - mmc_req_is_special(req)) + if ((!req && !(mq->flags & MMC_QUEUE_NEW_REQUEST)) || req_is_special) /* * Release host when there are no more requests * and after special request(discard, flush) is done. diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c index 29578e98603d..708057261b38 100644 --- a/drivers/mmc/card/queue.c +++ b/drivers/mmc/card/queue.c @@ -65,6 +65,8 @@ static int mmc_queue_thread(void *d) spin_unlock_irq(q->queue_lock); if (req || mq->mqrq_prev->req) { + bool req_is_special = mmc_req_is_special(req); + set_current_state(TASK_RUNNING); mq->issue_fn(mq, req); cond_resched(); @@ -80,7 +82,7 @@ static int mmc_queue_thread(void *d) * has been finished. Do not assign it to previous * request. */ - if (mmc_req_is_special(req)) + if (req_is_special) mq->mqrq_cur->req = NULL; mq->mqrq_prev->brq.mrq.data = NULL; |