From b7aa84d9cb9f26da1a9312c3e39dbd1a3c25a426 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" <martin.petersen@oracle.com> Date: Tue, 8 Apr 2014 22:43:43 -0400 Subject: [PATCH] block: Fix for_each_bvec() Commit 4550dd6c6b062 introduced for_each_bvec() which iterates over each bvec attached to a bio or bip. However, the macro fails to check bi_size before dereferencing which can lead to crashes while counting/mapping integrity scatterlist segments. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Cc: Kent Overstreet <kmo@daterainc.com> Cc: Nicholas Bellinger <nab@linux-iscsi.org> Cc: <stable@vger.kernel.org> # v3.14+ Signed-off-by: Jens Axboe <axboe@fb.com> --- include/linux/bio.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/include/linux/bio.h b/include/linux/bio.h index 5a4d39b4686b..5aa372a7380c 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -216,9 +216,9 @@ static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter, } #define for_each_bvec(bvl, bio_vec, iter, start) \ - for ((iter) = start; \ - (bvl) = bvec_iter_bvec((bio_vec), (iter)), \ - (iter).bi_size; \ + for (iter = (start); \ + (iter).bi_size && \ + ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \ bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len)) -- GitLab