Hi Mauro,
On 10/16/24 12:22, Mauro Carvalho Chehab wrote:
The current logic allows word to be less than 2. If this happens,
there will be buffer overflows. 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@xxxxxxxxxxxxxxx
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
---
.../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;
}
Seems reasonable.
Reviewed-by: Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx>
--
Best regards,
Jacek Anaszewski
