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authorJens Axboe <axboe@kernel.dk>2018-06-09 06:37:14 -0600
committerJens Axboe <axboe@kernel.dk>2018-06-09 06:37:14 -0600
commit190b02ed79e08983bf62d47c05945c1b06a3d7d5 (patch)
tree7b1d6db69efaf3ccb7d888d7cdfa1ccb59798178 /block/blk-flush.c
parent77016199f11eacd7b23e2faeb4d0f36166e3530b (diff)
downloadlwn-190b02ed79e08983bf62d47c05945c1b06a3d7d5.tar.gz
lwn-190b02ed79e08983bf62d47c05945c1b06a3d7d5.zip
block: fix use-after-free in block flush handling
A recent commit reused the original request flags for the flush queue handling. However, for some of the kick flush cases, the original request was already completed. This caused a use after free, if blk-mq wasn't used. Fixes: 84fca1b0c461 ("block: pass failfast and driver-specific flags to flush requests") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-flush.c')
-rw-r--r--block/blk-flush.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 058abdb50f31..ce41f666de3e 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -169,9 +169,11 @@ static bool blk_flush_complete_seq(struct request *rq,
struct request_queue *q = rq->q;
struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx];
bool queued = false, kicked;
+ unsigned int cmd_flags;
BUG_ON(rq->flush.seq & seq);
rq->flush.seq |= seq;
+ cmd_flags = rq->cmd_flags;
if (likely(!error))
seq = blk_flush_cur_seq(rq);
@@ -212,7 +214,7 @@ static bool blk_flush_complete_seq(struct request *rq,
BUG();
}
- kicked = blk_kick_flush(q, fq, rq->cmd_flags);
+ kicked = blk_kick_flush(q, fq, cmd_flags);
return kicked | queued;
}