From: Christoph Hellwig Date: Wed, 24 Feb 2021 07:24:04 +0000 (+0100) Subject: block-crypto-fallback: use a bio_set for splitting bios X-Git-Tag: microblaze-v5.13~12^2~5 X-Git-Url: http://git.monstr.eu/?p=linux-2.6-microblaze.git;a=commitdiff_plain;h=5407334c53e9922c1c3fb28801e489d0b74f2c8d block-crypto-fallback: use a bio_set for splitting bios bio_split with a NULL bs argumen used to fall back to kmalloc the bio, which does not guarantee forward progress and could to deadlocks. Now that the overloading of the NULL bs argument to bio_alloc_bioset has been removed it crashes instead. Fix all that by using a special crafted bioset. Fixes: 3175199ab0ac ("block: split bio_kmalloc from bio_alloc_bioset") Reported-by: John Stultz Signed-off-by: Christoph Hellwig Tested-by: John Stultz Signed-off-by: Jens Axboe --- diff --git a/block/blk-crypto-fallback.c b/block/blk-crypto-fallback.c index e8327c50d7c9..c176b7af56a7 100644 --- a/block/blk-crypto-fallback.c +++ b/block/blk-crypto-fallback.c @@ -80,6 +80,7 @@ static struct blk_crypto_keyslot { static struct blk_keyslot_manager blk_crypto_ksm; static struct workqueue_struct *blk_crypto_wq; static mempool_t *blk_crypto_bounce_page_pool; +static struct bio_set crypto_bio_split; /* * This is the key we set when evicting a keyslot. This *should* be the all 0's @@ -224,7 +225,8 @@ static bool blk_crypto_split_bio_if_needed(struct bio **bio_ptr) if (num_sectors < bio_sectors(bio)) { struct bio *split_bio; - split_bio = bio_split(bio, num_sectors, GFP_NOIO, NULL); + split_bio = bio_split(bio, num_sectors, GFP_NOIO, + &crypto_bio_split); if (!split_bio) { bio->bi_status = BLK_STS_RESOURCE; return false; @@ -538,9 +540,13 @@ static int blk_crypto_fallback_init(void) prandom_bytes(blank_key, BLK_CRYPTO_MAX_KEY_SIZE); - err = blk_ksm_init(&blk_crypto_ksm, blk_crypto_num_keyslots); + err = bioset_init(&crypto_bio_split, 64, 0, 0); if (err) goto out; + + err = blk_ksm_init(&blk_crypto_ksm, blk_crypto_num_keyslots); + if (err) + goto fail_free_bioset; err = -ENOMEM; blk_crypto_ksm.ksm_ll_ops = blk_crypto_ksm_ll_ops; @@ -591,6 +597,8 @@ fail_free_wq: destroy_workqueue(blk_crypto_wq); fail_free_ksm: blk_ksm_destroy(&blk_crypto_ksm); +fail_free_bioset: + bioset_exit(&crypto_bio_split); out: return err; }