[FFmpeg-devel] [PATCH 1/2] libavutil/base64: Try not to write over the array end

[FFmpeg-devel] [PATCH 1/2] libavutil/base64: Try not to write over the array end

[Michael Niedermayer]

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavutil/base64.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libavutil/base64.c b/libavutil/base64.c
index 3e66f4fcbe5..69e11e6f5e1 100644
--- a/libavutil/base64.c
+++ b/libavutil/base64.c
@@ -127,10 +127,12 @@ validity_check:
     }
 
 out3:
-    *dst++ = v >> 10;
+    if (end - dst)
+        *dst++ = v >> 10;
     v <<= 2;
 out2:
-    *dst++ = v >> 4;
+    if (end - dst)
+        *dst++ = v >> 4;
 out1:
 out0:
     return bits & 1 ? AVERROR_INVALIDDATA : out ? dst - out : 0;
-- 
2.43.2

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

[FFmpeg-devel] [PATCH 2/2] avutil/tests/base64: Check with too short output array

[Michael Niedermayer]

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavutil/tests/base64.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/libavutil/tests/base64.c b/libavutil/tests/base64.c
index 400e01cefe4..66d0fdc1fc8 100644
--- a/libavutil/tests/base64.c
+++ b/libavutil/tests/base64.c
@@ -64,6 +64,16 @@ static int test_encode_decode(const uint8_t *data, unsigned int data_size,
         printf("Failed: decode to NULL buffer\n");
         return 1;
     }
+    if (data_size > 0 && (data2_size = av_base64_decode(data2, encoded, data_size - 1)) != data_size - 1) {
+        printf("Failed: out of array write\n"
+               "Encoded:\n%s\n", encoded);
+        return 1;
+    }
+    if (data_size > 1 && (data2_size = av_base64_decode(data2, encoded, data_size - 2)) != data_size - 2) {
+        printf("Failed: out of array write\n"
+               "Encoded:\n%s\n", encoded);
+        return 1;
+    }
     if (strlen(encoded)) {
         char *end = strchr(encoded, '=');
         if (!end)
-- 
2.43.2

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

Re: [FFmpeg-devel] [PATCH 1/2] libavutil/base64: Try not to write over the array end

[Michael Niedermayer]

[-- Attachment #1.1: Type: text/plain, Size: 488 bytes --]

On Sat, May 11, 2024 at 03:22:53AM +0200, Michael Niedermayer wrote:
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavutil/base64.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)

will apply patchset

[...]
--
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The bravest are surely those who have the clearest vision
of what is before them, glory and danger alike, and yet
notwithstanding go out to meet it. -- Thucydides

[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]

[-- Attachment #2: Type: text/plain, Size: 251 bytes --]

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".