diff options
| author | Jens Axboe <axboe@fb.com> | 2017-02-24 21:19:32 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-02-24 21:19:32 +0100 |
| commit | 61febef40bfe8ab68259d8545257686e8a0d91d1 (patch) | |
| tree | 94d52c7e6d62b1f7381fc615c8964e0751e7ca08 | |
| parent | blk-mq-sched: separate mark hctx and queue restart operations (diff) | |
| download | linux-61febef40bfe8ab68259d8545257686e8a0d91d1.tar.xz linux-61febef40bfe8ab68259d8545257686e8a0d91d1.zip | |
dm-rq: don't dereference request payload after ending request
Bart reported a case where dm would crash with use-after-free
poison. This is due to dm_softirq_done() accessing memory
associated with a request after calling end_request on it.
This is most visible on !blk-mq, since we free the memory
immediately for that case.
Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: eb8db831be80 ("dm: always defer request allocation to the owner of the request_queue")
Signed-off-by: Jens Axboe <axboe@fb.com>
| -rw-r--r-- | drivers/md/dm-rq.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c index 67d76f21fecd..28955b94d2b2 100644 --- a/drivers/md/dm-rq.c +++ b/drivers/md/dm-rq.c @@ -328,13 +328,15 @@ static void dm_softirq_done(struct request *rq) int rw; if (!clone) { - rq_end_stats(tio->md, rq); + struct mapped_device *md = tio->md; + + rq_end_stats(md, rq); rw = rq_data_dir(rq); if (!rq->q->mq_ops) blk_end_request_all(rq, tio->error); else blk_mq_end_request(rq, tio->error); - rq_completed(tio->md, rw, false); + rq_completed(md, rw, false); return; } |