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 03393E56C for ; Mon, 15 May 2023 16:44:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7392EC433EF; Mon, 15 May 2023 16:44:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1684169073; bh=sFrfPY7EMkBSX+YimTIkq9AjymcaZRkC1tl3CcGmGv8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=n8s7XEeoxKnmBwl7PMcr/EIiRL4TyDzkHK0TUhQW1I5MixLBN0Ij/JDrNJ0QdSYzH y2ABQ1t2XdtX+4UZKeQFOUm9p0uCZWvYoWQwuxzzDnWqYnfhOa8LVsj5+UY9yEjJtn lkN0w6Firb9OWOZZWcT2yKG1pQUjE4+i4eH9Asrw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mikulas Patocka , Mike Snitzer Subject: [PATCH 4.19 134/191] dm flakey: fix a crash with invalid table line Date: Mon, 15 May 2023 18:26:11 +0200 Message-Id: <20230515161712.245342369@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230515161707.203549282@linuxfoundation.org> References: <20230515161707.203549282@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Mikulas Patocka commit 98dba02d9a93eec11bffbb93c7c51624290702d2 upstream. This command will crash with NULL pointer dereference: dmsetup create flakey --table \ "0 `blockdev --getsize /dev/ram0` flakey /dev/ram0 0 0 1 2 corrupt_bio_byte 512" Fix the crash by checking if arg_name is non-NULL before comparing it. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-flakey.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/md/dm-flakey.c +++ b/drivers/md/dm-flakey.c @@ -124,9 +124,9 @@ static int parse_features(struct dm_arg_ * Direction r or w? */ arg_name = dm_shift_arg(as); - if (!strcasecmp(arg_name, "w")) + if (arg_name && !strcasecmp(arg_name, "w")) fc->corrupt_bio_rw = WRITE; - else if (!strcasecmp(arg_name, "r")) + else if (arg_name && !strcasecmp(arg_name, "r")) fc->corrupt_bio_rw = READ; else { ti->error = "Invalid corrupt bio direction (r or w)";