linux-kernel - [PATCH v2 07/13] media: s5p-jpeg: prevent buffer overflows

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <172461a2e8b2a1a4f01add73afae777463ea0fb8.1729230718.git.mchehab+huawei@kernel.org>
Date: Fri, 18 Oct 2024 07:53:09 +0200
From: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
To: 
Cc: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>,
	Andrzej Pietrasiewicz <andrzejtp2010@...il.com>,
	Hans Verkuil <hans.verkuil@...co.com>,
	Jacek Anaszewski <jacek.anaszewski@...il.com>,
	Mauro Carvalho Chehab <mchehab+huawei@...nel.org>,
	Sylwester Nawrocki <s.nawrocki@...sung.com>,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	linux-media@...r.kernel.org,
	stable@...r.kernel.org
Subject: [PATCH v2 07/13] media: s5p-jpeg: prevent buffer overflows

The current logic allows word to be less than 2. If this happens,
there will be buffer overflows, as reported by smatch. Add extra
checks to prevent it.

While here, remove an unused word = 0 assignment.

Fixes: 6c96dbbc2aa9 ("[media] s5p-jpeg: add support for 5433")
Cc: stable@...r.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
Reviewed-by: Jacek Anaszewski <jacek.anaszewski@...il.com>
---
 .../media/platform/samsung/s5p-jpeg/jpeg-core.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/media/platform/samsung/s5p-jpeg/jpeg-core.c b/drivers/media/platform/samsung/s5p-jpeg/jpeg-core.c
index d2c4a0178b3c..1db4609b3557 100644
--- a/drivers/media/platform/samsung/s5p-jpeg/jpeg-core.c
+++ b/drivers/media/platform/samsung/s5p-jpeg/jpeg-core.c
@@ -775,11 +775,14 @@ static void exynos4_jpeg_parse_decode_h_tbl(struct s5p_jpeg_ctx *ctx)
 		(unsigned long)vb2_plane_vaddr(&vb->vb2_buf, 0) + ctx->out_q.sos + 2;
 	jpeg_buffer.curr = 0;
 
-	word = 0;
-
 	if (get_word_be(&jpeg_buffer, &word))
 		return;
-	jpeg_buffer.size = (long)word - 2;
+
+	if (word < 2)
+		jpeg_buffer.size = 0;
+	else
+		jpeg_buffer.size = (long)word - 2;
+
 	jpeg_buffer.data += 2;
 	jpeg_buffer.curr = 0;
 
@@ -1058,6 +1061,7 @@ static int get_word_be(struct s5p_jpeg_buffer *buf, unsigned int *word)
 	if (byte == -1)
 		return -1;
 	*word = (unsigned int)byte | temp;
+
 	return 0;
 }
 
@@ -1145,7 +1149,7 @@ static bool s5p_jpeg_parse_hdr(struct s5p_jpeg_q_data *result,
 			if (get_word_be(&jpeg_buffer, &word))
 				break;
 			length = (long)word - 2;
-			if (!length)
+			if (length <= 0)
 				return false;
 			sof = jpeg_buffer.curr; /* after 0xffc0 */
 			sof_len = length;
@@ -1176,7 +1180,7 @@ static bool s5p_jpeg_parse_hdr(struct s5p_jpeg_q_data *result,
 			if (get_word_be(&jpeg_buffer, &word))
 				break;
 			length = (long)word - 2;
-			if (!length)
+			if (length <= 0)
 				return false;
 			if (n_dqt >= S5P_JPEG_MAX_MARKER)
 				return false;
@@ -1189,7 +1193,7 @@ static bool s5p_jpeg_parse_hdr(struct s5p_jpeg_q_data *result,
 			if (get_word_be(&jpeg_buffer, &word))
 				break;
 			length = (long)word - 2;
-			if (!length)
+			if (length <= 0)
 				return false;
 			if (n_dht >= S5P_JPEG_MAX_MARKER)
 				return false;
@@ -1214,6 +1218,7 @@ static bool s5p_jpeg_parse_hdr(struct s5p_jpeg_q_data *result,
 			if (get_word_be(&jpeg_buffer, &word))
 				break;
 			length = (long)word - 2;
+			/* No need to check underflows as skip() does it  */
 			skip(&jpeg_buffer, length);
 			break;
 		}
-- 
2.47.0