Security: Potential Buffer Overflow in AVIOFileLikeContext::read#1451
Security: Potential Buffer Overflow in AVIOFileLikeContext::read#1451tomaioo wants to merge 1 commit into
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In AVIOFileLikeContext.cpp, the read function uses `std::memcpy(buf, bytesView.data(), numBytesRead)` where `numBytesRead` comes from Python file-like objects. While there are checks, the validation `numBytesRead <= request` only ensures it's less than the request, but doesn't validate against the actual buffer size `buf_size` passed by FFmpeg. The loop increments `buf` and `totalNumRead`, but if Python returns more bytes than expected in edge cases, this could cause issues. Signed-off-by: tomaioo <203048277+tomaioo@users.noreply.github.com>
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Summary
Security: Potential Buffer Overflow in AVIOFileLikeContext::read
Problem
Severity:
Medium| File:src/torchcodec/_core/AVIOFileLikeContext.cpp:L39In AVIOFileLikeContext.cpp, the read function uses
std::memcpy(buf, bytesView.data(), numBytesRead)wherenumBytesReadcomes from Python file-like objects. While there are checks, the validationnumBytesRead <= requestonly ensures it's less than the request, but doesn't validate against the actual buffer sizebuf_sizepassed by FFmpeg. The loop incrementsbufandtotalNumRead, but if Python returns more bytes than expected in edge cases, this could cause issues.Solution
Add explicit bounds checking to ensure
numBytesReadnever exceedsbuf_size - totalNumReadbefore the memcpy. Consider usingstd::minto clamp the value.Changes
src/torchcodec/_core/AVIOFileLikeContext.cpp(modified)