From patchwork Wed Sep 2 05:15:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 11749855 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 15EA3138A for ; Wed, 2 Sep 2020 05:16:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E743A20786 for ; Wed, 2 Sep 2020 05:16:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599023793; bh=7NioYolFiINFX16bP6jasJwLznUoujiPqwtNXECfglw=; h=From:To:Cc:Subject:Date:List-ID:From; b=nBlNHjhJgtO8JF3VdkHXEa3+gfKgoh75IXc4MAEj4wiTpB/QK5arIo7G2mgIiA0Jl gZ2c3B+6Ls+j+kVHzrpfIAyrW+hUGyPrjBEGVDbKM3g5NrXFhCaXN4WD3rTJQ3hz0+ oivKev1+GTBwXZGH88V3ucRsTOfMR7YvpL4hJpjs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726144AbgIBFQd (ORCPT ); Wed, 2 Sep 2020 01:16:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:54518 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726021AbgIBFQb (ORCPT ); Wed, 2 Sep 2020 01:16:31 -0400 Received: from sol.localdomain (ip-99-203-42-15.pools.cgn.spcsdns.net [99.203.42.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2871020758; Wed, 2 Sep 2020 05:16:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599023791; bh=7NioYolFiINFX16bP6jasJwLznUoujiPqwtNXECfglw=; h=From:To:Cc:Subject:Date:From; b=D/gC+Fus0Uz8ar1uLb2McY6fv5637pAjwL8mk3X2MQTM0poesQxR1wscwnuxWt4Sf O15rc4jMx/3mSepJTGBZbnpeZkfzSO8sNLZpy4Ysh2s1rjbEfn+2gGcCbFBp15Un9k YZw8TI5XNLwhlp0c8WRBSUvTy5wQ1i3OSiqczkdo= From: Eric Biggers To: linux-block@vger.kernel.org, Jens Axboe Cc: dm-devel@redhat.com, Satya Tangirala , Miaohe Lin Subject: [PATCH] block: make bio_crypt_clone() return an error code Date: Tue, 1 Sep 2020 22:15:11 -0700 Message-Id: <20200902051511.79821-1-ebiggers@kernel.org> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Eric Biggers Callers of bio_clone_fast() may use a gfp_mask that excludes GFP_DIRECT_RECLAIM. For example, map_request() uses GFP_ATOMIC. If this were to happen, the mempool_alloc() in __bio_crypt_clone() can fail, causing a NULL dereference. In reality map_request() currently never has to clone an encryption context, since inline encryption isn't yet supported on device-mapper devices at all, let alone on request-based ones. But it is fragile to rely on this. Just make bio_crypt_clone() able to fail, similar to bio_integrity_clone(). Reported-by: Miaohe Lin Cc: Satya Tangirala Signed-off-by: Eric Biggers --- block/bio.c | 20 +++++++++----------- block/blk-crypto.c | 5 ++++- block/bounce.c | 19 +++++++++---------- drivers/md/dm.c | 7 ++++--- include/linux/blk-crypto.h | 9 +++++---- 5 files changed, 31 insertions(+), 29 deletions(-) base-commit: f75aef392f869018f78cfedf3c320a6b3fcfda6b 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 fb0255d25e4b2..e987b417d702f 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..d0dba84f6a608 100644 --- a/include/linux/blk-crypto.h +++ b/include/linux/blk-crypto.h @@ -112,12 +112,13 @@ 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); +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 */