From: Eric Biggers <[email protected]> bio_crypt_clone() assumes its gfp_mask argument always includes __GFP_DIRECT_RECLAIM, so that the mempool_alloc() will always succeed.
However, bio_crypt_clone() might be called with GFP_ATOMIC via setup_clone() in drivers/md/dm-rq.c, or with GFP_NOWAIT via kcryptd_io_read() in drivers/md/dm-crypt.c. Neither case is currently reachable with a bio that actually has an encryption context. However, it's fragile to rely on this. Just make bio_crypt_clone() able to fail, analogous to bio_integrity_clone(). Reported-by: Miaohe Lin <[email protected]> Cc: Satya Tangirala <[email protected]> Signed-off-by: Eric Biggers <[email protected]> --- block/bio.c | 20 +++++++++----------- block/blk-crypto.c | 5 ++++- block/bounce.c | 19 +++++++++---------- drivers/md/dm.c | 7 ++++--- include/linux/blk-crypto.h | 20 ++++++++++++++++---- 5 files changed, 42 insertions(+), 29 deletions(-) diff --git a/block/bio.c b/block/bio.c index a9931f23d9332..b42e046b12eb3 100644 --- a/block/bio.c +++ b/block/bio.c @@ -713,20 +713,18 @@ struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs) __bio_clone_fast(b, bio); - bio_crypt_clone(b, bio, gfp_mask); + if (bio_crypt_clone(b, bio, gfp_mask) < 0) + goto err_put; - if (bio_integrity(bio)) { - int ret; - - ret = bio_integrity_clone(b, bio, gfp_mask); - - if (ret < 0) { - bio_put(b); - return NULL; - } - } + if (bio_integrity(bio) && + bio_integrity_clone(b, bio, gfp_mask) < 0) + goto err_put; return b; + +err_put: + bio_put(b); + return NULL; } EXPORT_SYMBOL(bio_clone_fast); diff --git a/block/blk-crypto.c b/block/blk-crypto.c index 2d5e60023b08b..a3f27a19067c9 100644 --- a/block/blk-crypto.c +++ b/block/blk-crypto.c @@ -95,10 +95,13 @@ void __bio_crypt_free_ctx(struct bio *bio) bio->bi_crypt_context = NULL; } -void __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask) +int __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask) { dst->bi_crypt_context = mempool_alloc(bio_crypt_ctx_pool, gfp_mask); + if (!dst->bi_crypt_context) + return -ENOMEM; *dst->bi_crypt_context = *src->bi_crypt_context; + return 0; } EXPORT_SYMBOL_GPL(__bio_crypt_clone); diff --git a/block/bounce.c b/block/bounce.c index 431be88a02405..162a6eee89996 100644 --- a/block/bounce.c +++ b/block/bounce.c @@ -267,22 +267,21 @@ static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask, break; } - bio_crypt_clone(bio, bio_src, gfp_mask); + if (bio_crypt_clone(bio, bio_src, gfp_mask) < 0) + goto err_put; - if (bio_integrity(bio_src)) { - int ret; - - ret = bio_integrity_clone(bio, bio_src, gfp_mask); - if (ret < 0) { - bio_put(bio); - return NULL; - } - } + if (bio_integrity(bio_src) && + bio_integrity_clone(bio, bio_src, gfp_mask) < 0) + goto err_put; bio_clone_blkg_association(bio, bio_src); blkcg_bio_issue_init(bio); return bio; + +err_put: + bio_put(bio); + return NULL; } static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 3dedd9cc4fb65..5487c3ff74b51 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1326,14 +1326,15 @@ static int clone_bio(struct dm_target_io *tio, struct bio *bio, sector_t sector, unsigned len) { struct bio *clone = &tio->clone; + int r; __bio_clone_fast(clone, bio); - bio_crypt_clone(clone, bio, GFP_NOIO); + r = bio_crypt_clone(clone, bio, GFP_NOIO); + if (r < 0) + return r; if (bio_integrity(bio)) { - int r; - if (unlikely(!dm_target_has_integrity(tio->ti->type) && !dm_target_passes_integrity(tio->ti->type))) { DMWARN("%s: the target %s doesn't support integrity data.", diff --git a/include/linux/blk-crypto.h b/include/linux/blk-crypto.h index e82342907f2b1..69b24fe92cbf1 100644 --- a/include/linux/blk-crypto.h +++ b/include/linux/blk-crypto.h @@ -112,12 +112,24 @@ static inline bool bio_has_crypt_ctx(struct bio *bio) #endif /* CONFIG_BLK_INLINE_ENCRYPTION */ -void __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask); -static inline void bio_crypt_clone(struct bio *dst, struct bio *src, - gfp_t gfp_mask) +int __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask); +/** + * bio_crypt_clone - clone bio encryption context + * @dst: destination bio + * @src: source bio + * @gfp_mask: memory allocation flags + * + * If @src has an encryption context, clone it to @dst. + * + * Return: 0 on success, -ENOMEM if out of memory. -ENOMEM is only possible if + * @gfp_mask doesn't include %__GFP_DIRECT_RECLAIM. + */ +static inline int bio_crypt_clone(struct bio *dst, struct bio *src, + gfp_t gfp_mask) { if (bio_has_crypt_ctx(src)) - __bio_crypt_clone(dst, src, gfp_mask); + return __bio_crypt_clone(dst, src, gfp_mask); + return 0; } #endif /* __LINUX_BLK_CRYPTO_H */ -- 2.28.0 -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
