# \[PATCH v4 1/2\] block: Fix a buffer overrun in bio\_integrity\_split() - From: Kent Overstreet \ - Date: 2012-10-15 20:18:29 - List: linux-bcache - Page: https://ratatoskr.run/linux-bcache/2012/10/3939747 - Thread: https://ratatoskr.run/linux-bcache/2012/10/3939710/t.md ```text bio_integrity_split() seemed to be confusing pointers and arrays - bip_vec in bio_integrity_payload was an array appended to the end of the payload, so the bio_vecs in struct bio_pair should have come after the bio_integrity_payload they're for. Fix it by making bip_vec a pointer to the inline vecs - a later patch is going to make more use of this pointer. Signed-off-by: Kent Overstreet CC: Jens Axboe CC: Martin K. Petersen --- fs/bio-integrity.c | 5 +++-- include/linux/bio.h | 4 +++- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c index a3f28f3..94fa1c5 100644 --- a/fs/bio-integrity.c +++ b/fs/bio-integrity.c @@ -112,6 +112,7 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio, bip->bip_slab = idx; bip->bip_bio = bio; + bip->bip_vec = bip->bip_inline_vecs; bio->bi_integrity = bip; return bip; @@ -697,8 +698,8 @@ void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors) bp->iv1 = bip->bip_vec[0]; bp->iv2 = bip->bip_vec[0]; - bp->bip1.bip_vec[0] = bp->iv1; - bp->bip2.bip_vec[0] = bp->iv2; + bp->bip1.bip_vec = &bp->iv1; + bp->bip2.bip_vec = &bp->iv2; bp->iv1.bv_len = sectors * bi->tuple_size; bp->iv2.bv_offset += sectors * bi->tuple_size; diff --git a/include/linux/bio.h b/include/linux/bio.h index b31036f..81004fd 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -182,7 +182,9 @@ struct bio_integrity_payload { unsigned short bip_idx; /* current bip_vec index */ struct work_struct bip_work; /* I/O completion */ - struct bio_vec bip_vec[0]; /* embedded bvec array */ + + struct bio_vec *bip_vec; + struct bio_vec bip_inline_vecs[0];/* embedded bvec array */ }; #endif /* CONFIG_BLK_DEV_INTEGRITY */ -- 1.7.12 ```