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@vger.kernel.org Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org --- .../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; }