From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9162479DE; Sat, 30 Dec 2023 12:06:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ykTWDBTw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 19CDFC433C7; Sat, 30 Dec 2023 12:06:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1703937992; bh=/E1q+mNnkbZJDixEczimPNJPOknVjqo1+3f7Tfow3Ow=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ykTWDBTwoJlm8k0HWhqZete2HZPM3+Q8bTFGeFBAMSMOwGpgnUZlk0aH7iZ2X6wbJ ZHrNHVHMQ+ZVDKjBqEFGDnx0tU+Bg2uMJGyuc2vY7z1p8B1vfCD/QlY9NIIryzzcLL odDhNQhIYQn+7ENkrQngNKGfLZWFtEjZ76Dpzb4s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mikulas Patocka , Mike Snitzer Subject: [PATCH 6.6 142/156] dm-integrity: dont modify bios immutable bio_vec in integrity_metadata() Date: Sat, 30 Dec 2023 11:59:56 +0000 Message-ID: <20231230115816.967594033@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231230115812.333117904@linuxfoundation.org> References: <20231230115812.333117904@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mikulas Patocka commit b86f4b790c998afdbc88fe1aa55cfe89c4068726 upstream. __bio_for_each_segment assumes that the first struct bio_vec argument doesn't change - it calls "bio_advance_iter_single((bio), &(iter), (bvl).bv_len)" to advance the iterator. Unfortunately, the dm-integrity code changes the bio_vec with "bv.bv_len -= pos". When this code path is taken, the iterator would be out of sync and dm-integrity would report errors. This happens if the machine is out of memory and "kmalloc" fails. Fix this bug by making a copy of "bv" and changing the copy instead. Fixes: 7eada909bfd7 ("dm: add integrity target") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-integrity.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -1765,11 +1765,12 @@ static void integrity_metadata(struct wo sectors_to_process = dio->range.n_sectors; __bio_for_each_segment(bv, bio, iter, dio->bio_details.bi_iter) { + struct bio_vec bv_copy = bv; unsigned int pos; char *mem, *checksums_ptr; again: - mem = bvec_kmap_local(&bv); + mem = bvec_kmap_local(&bv_copy); pos = 0; checksums_ptr = checksums; do { @@ -1778,7 +1779,7 @@ again: sectors_to_process -= ic->sectors_per_block; pos += ic->sectors_per_block << SECTOR_SHIFT; sector += ic->sectors_per_block; - } while (pos < bv.bv_len && sectors_to_process && checksums != checksums_onstack); + } while (pos < bv_copy.bv_len && sectors_to_process && checksums != checksums_onstack); kunmap_local(mem); r = dm_integrity_rw_tag(ic, checksums, &dio->metadata_block, &dio->metadata_offset, @@ -1803,9 +1804,9 @@ again: if (!sectors_to_process) break; - if (unlikely(pos < bv.bv_len)) { - bv.bv_offset += pos; - bv.bv_len -= pos; + if (unlikely(pos < bv_copy.bv_len)) { + bv_copy.bv_offset += pos; + bv_copy.bv_len -= pos; goto again; } }