Add defensive limits for BMFF metadata counts during parsing#3187
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uwezkhan wants to merge 6 commits intoAOMediaCodec:mainfrom
Open
Add defensive limits for BMFF metadata counts during parsing#3187uwezkhan wants to merge 6 commits intoAOMediaCodec:mainfrom
uwezkhan wants to merge 6 commits intoAOMediaCodec:mainfrom
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y-guyon
reviewed
May 4, 2026
wantehchang
reviewed
May 5, 2026
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This patch adds internal defensive limits for attacker-controlled BMFF metadata counts parsed from AVIF/HEIF files.
Several parser paths allocate memory or perform repeated processing based on counts read directly from the bitstream (items, properties, extents, groups, etc.). Malformed files can use excessive values here to trigger disproportionate memory usage and parser overhead.
To mitigate this, this change introduces conservative internal upper bounds for key metadata structures and rejects files that exceed those limits during parsing.
The limits are intentionally generous for legitimate AVIF content while preventing pathological resource-exhaustion cases from malformed inputs.