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| author | Ming Lei <ming.lei@redhat.com> | 2019-04-17 09:11:26 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-04-19 11:32:14 -0600 |
| commit | 6bedf00e55e5dd0a4ed1ad3f06131edd6fb56ec8 (patch) | |
| tree | a34352d078072adaff40d3aff0851ea0a87c94a0 /include/linux/bvec.h | |
| parent | b40fabc05ea047f6af5933d26a5483873340b0d4 (diff) | |
| download | lwn-6bedf00e55e5dd0a4ed1ad3f06131edd6fb56ec8.tar.gz lwn-6bedf00e55e5dd0a4ed1ad3f06131edd6fb56ec8.zip | |
block: make sure that bvec length can't be overflow
bvec->bv_offset may be bigger than PAGE_SIZE sometimes, such as,
when one bio is splitted in the middle of one bvec via bio_split(),
and bi_iter.bi_bvec_done is used to build offset of the 1st bvec of
remained bio. And the remained bio's bvec may be re-submitted to fs
layer via ITER_IBVEC, such as loop and nvme-loop.
So we have to make sure that every bvec's offset is less than
PAGE_SIZE from bio_for_each_segment_all() because some drivers(loop,
nvme-loop) passes the splitted bvec to fs layer via ITER_BVEC.
This patch fixes this issue reported by Zhang Yi When running nvme/011.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Yi Zhang <yi.zhang@redhat.com>
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Fixes: 6dc4f100c175 ("block: allow bio_for_each_segment_all() to iterate over multi-page bvec")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/linux/bvec.h')
| -rw-r--r-- | include/linux/bvec.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/include/linux/bvec.h b/include/linux/bvec.h index 3bc91879e1e2..ff13cbc1887d 100644 --- a/include/linux/bvec.h +++ b/include/linux/bvec.h @@ -160,8 +160,9 @@ static inline void bvec_advance(const struct bio_vec *bvec, bv->bv_page = nth_page(bv->bv_page, 1); bv->bv_offset = 0; } else { - bv->bv_page = bvec->bv_page; - bv->bv_offset = bvec->bv_offset; + bv->bv_page = bvec_nth_page(bvec->bv_page, bvec->bv_offset / + PAGE_SIZE); + bv->bv_offset = bvec->bv_offset & ~PAGE_MASK; } bv->bv_len = min_t(unsigned int, PAGE_SIZE - bv->bv_offset, bvec->bv_len - iter_all->done); |