From: Michael Niedermayer <mich...@niedermayer.cc> Enable the checked bitreader to avoid overread. Also add a few checks in loops and between blocks so we exit instead of continued execution. Alternatively we could add manual checks so that no overread can happen. This would be slightly faster but a bit more work and a bit more fragile
Fixes: Out of array accesses Fixes: 59640/clusterfuzz-testcase-minimized-ffmpeg_dem_JPEGXL_ANIM_fuzzer-6584117345779712 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> --- libavformat/jpegxl_probe.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/libavformat/jpegxl_probe.c b/libavformat/jpegxl_probe.c index 1d9c014f19..e15e9eee49 100644 --- a/libavformat/jpegxl_probe.c +++ b/libavformat/jpegxl_probe.c @@ -21,6 +21,7 @@ #include "jpegxl_probe.h" +#define UNCHECKED_BITSTREAM_READER 0 #define BITSTREAM_READER_LE #include "libavcodec/get_bits.h" @@ -293,6 +294,8 @@ int ff_jpegxl_verify_codestream_header(const uint8_t *buf, int buflen, int valid skip_bits_long(gb, 1); } } + if (get_bits_left(gb) < 1) + return AVERROR_INVALIDDATA; if (!all_default) { jpegxl_skip_bit_depth(gb); @@ -307,6 +310,8 @@ int ff_jpegxl_verify_codestream_header(const uint8_t *buf, int buflen, int valid for (uint32_t i = 0; i < num_extra_channels; i++) { if (jpegxl_read_extra_channel_info(gb, validate_level) < 0) return -1; + if (get_bits_left(gb) < 1) + return AVERROR_INVALIDDATA; } xyb_encoded = get_bits1(gb); @@ -336,8 +341,11 @@ int ff_jpegxl_verify_codestream_header(const uint8_t *buf, int buflen, int valid return -1; if (primaries == FF_JPEGXL_PR_CUSTOM) { /* ux/uy values for r,g,b */ - for (int i = 0; i < 6; i++) + for (int i = 0; i < 6; i++) { jxl_u32(gb, 0, 524288, 1048576, 2097152, 19, 19, 20, 21); + if (get_bits_left(gb) < 1) + return AVERROR_INVALIDDATA; + } } } } @@ -363,10 +371,14 @@ int ff_jpegxl_verify_codestream_header(const uint8_t *buf, int buflen, int valid skip_bits_long(gb, 16 + 16 + 1 + 16); extensions = jpegxl_u64(gb); + if (get_bits_left(gb) < 1) + return AVERROR_INVALIDDATA; if (extensions) { for (int i = 0; i < 64; i++) { if (extensions & (UINT64_C(1) << i)) jpegxl_u64(gb); + if (get_bits_left(gb) < 1) + return AVERROR_INVALIDDATA; } } } -- 2.40.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
