[FFmpeg-cvslog] avformat/jpegxl_anim_dec: fix out of array read using buffer padding
Michael Niedermayer
git at videolan.org
Tue Jun 20 19:49:16 EEST 2023
ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun Jun 18 23:50:18 2023 +0200| [6a9d13acc26bf02a33b9b8b836bed26d9d43f303] | committer: Leo Izen
avformat/jpegxl_anim_dec: fix out of array read using buffer padding
Fixes: out of array read
Fixes: 59828/clusterfuzz-testcase-minimized-ffmpeg_dem_JPEGXL_ANIM_fuzzer-5029813220671488
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=6a9d13acc26bf02a33b9b8b836bed26d9d43f303
---
libavformat/jpegxl_anim_dec.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/libavformat/jpegxl_anim_dec.c b/libavformat/jpegxl_anim_dec.c
index 8d6ea5005c..956b56c1d8 100644
--- a/libavformat/jpegxl_anim_dec.c
+++ b/libavformat/jpegxl_anim_dec.c
@@ -112,7 +112,7 @@ static int jpegxl_collect_codestream_header(const uint8_t *input_buffer, int inp
static int jpegxl_anim_probe(const AVProbeData *p)
{
- uint8_t buffer[4096];
+ uint8_t buffer[4096 + AV_INPUT_BUFFER_PADDING_SIZE];
int copied;
/* this is a raw codestream */
@@ -127,7 +127,7 @@ static int jpegxl_anim_probe(const AVProbeData *p)
if (AV_RL64(p->buf) != FF_JPEGXL_CONTAINER_SIGNATURE_LE)
return 0;
- if (jpegxl_collect_codestream_header(p->buf, p->buf_size, buffer, sizeof(buffer), &copied) <= 0 || copied <= 0)
+ if (jpegxl_collect_codestream_header(p->buf, p->buf_size, buffer, sizeof(buffer) - AV_INPUT_BUFFER_PADDING_SIZE, &copied) <= 0 || copied <= 0)
return 0;
if (ff_jpegxl_verify_codestream_header(buffer, copied, 0) >= 1)
@@ -142,7 +142,8 @@ static int jpegxl_anim_read_header(AVFormatContext *s)
AVIOContext *pb = s->pb;
AVStream *st;
int offset = 0;
- uint8_t head[256];
+ uint8_t head[256 + AV_INPUT_BUFFER_PADDING_SIZE];
+ const int sizeofhead = sizeof(head) - AV_INPUT_BUFFER_PADDING_SIZE;
int headsize = 0;
int ctrl;
AVRational tb;
@@ -151,7 +152,7 @@ static int jpegxl_anim_read_header(AVFormatContext *s)
uint64_t sig16 = avio_rl16(pb);
if (sig16 == FF_JPEGXL_CODESTREAM_SIGNATURE_LE) {
AV_WL16(head, sig16);
- headsize = avio_read(s->pb, head + 2, sizeof(head) - 2);
+ headsize = avio_read(s->pb, head + 2, sizeofhead - 2);
if (headsize < 0)
return headsize;
headsize += 2;
@@ -182,10 +183,10 @@ static int jpegxl_anim_read_header(AVFormatContext *s)
if (av_buffer_realloc(&ctx->initial, ctx->initial->size + read) < 0)
return AVERROR(ENOMEM);
}
- jpegxl_collect_codestream_header(buf, read, head + headsize, sizeof(head) - headsize, &copied);
+ jpegxl_collect_codestream_header(buf, read, head + headsize, sizeofhead - headsize, &copied);
memcpy(ctx->initial->data + (ctx->initial->size - read), buf, read);
headsize += copied;
- if (headsize >= sizeof(head) || read < sizeof(buf))
+ if (headsize >= sizeofhead || read < sizeof(buf))
break;
}
}
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