From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
The bio pointer is being null checked hence it can be potentially
null, however earlier it is being derefefenced on the assignment of
front_seg_size. Avoid the dereference issue by only assigning
front_seg_size after bios has been null sanity checked.
Fixes: dcebd755926b ("block: use bio_for_each_bvec() to compute multi-page bvec count")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
block/blk-merge.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index bed065904677..1bec20fbe465 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -379,6 +379,7 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
return 1;
}
+ front_seg_size = bio->bi_seg_front_size;
fbio = bio;
seg_size = 0;
nr_phys_segs = 0;
--
2.20.1
