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| author | Ming Lei <ming.lei@redhat.com> | 2019-02-19 11:08:19 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-02-19 09:19:06 -0700 |
| commit | 49b1f22b567ba1d7d8174950be4398a69d0effb7 (patch) | |
| tree | 52811398366d5cc858edaebe17ca7cb1238a9777 | |
| parent | 6fb845f0e78de19eaaf6a2d351702474e44b6a9e (diff) | |
| download | linux-49b1f22b567ba1d7d8174950be4398a69d0effb7.tar.bz2 | |
block: avoid to READ fields of null bio
rq->bio can be NULL sometimes, such as flush request, so don't
read bio->bi_seg_front_size until this 'bio' is checked as valid.
Cc: Bart Van Assche <bvanassche@acm.org>
Reported-by: Bart Van Assche <bvanassche@acm.org>
Fixes: dcebd755926b0f39dd1e ("block: use bio_for_each_bvec() to compute multi-page bvec count")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-merge.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c index bed065904677..066b66430523 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -363,13 +363,15 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q, struct bio_vec bv, bvprv = { NULL }; int prev = 0; unsigned int seg_size, nr_phys_segs; - unsigned front_seg_size = bio->bi_seg_front_size; + unsigned front_seg_size; struct bio *fbio, *bbio; struct bvec_iter iter; if (!bio) return 0; + front_seg_size = bio->bi_seg_front_size; + switch (bio_op(bio)) { case REQ_OP_DISCARD: case REQ_OP_SECURE_ERASE: |