loader: x86_64: elf: Avoid reading beyond file end #125
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The ELF header contains offsets that the loader uses to find other structures. If those offsets are beyond the end of the file (or would go past the end of the file) it is essential to error out when attempting to read those. Using `Read::read_exact()` permits this. Signed-off-by: Bo Chen <chen.bo@intel.com> Co-authored-by: Rob Bradford <robert.bradford@intel.com>
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sboeuf
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We cannot mark the returned usize as must use unfortunately. This is what triggered the bug in linux-loader: rust-vmm/linux-loader#125. The least we can do is to validate that when there are more bytes requested than what the reader has available, we do return the correct number of the read. Unfortunately, when this result is not used it can lead to bugs. Signed-off-by: Andreea Florescu <fandree@amazon.com>
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We cannot mark the returned usize as must use unfortunately. This is what triggered the bug in linux-loader: rust-vmm/linux-loader#125. The least we can do is to validate that when there are more bytes requested than what the reader has available, we do return the correct number of the read. Unfortunately, when this result is not used it can lead to bugs. Signed-off-by: Andreea Florescu <fandree@amazon.com>
andreeaflorescu
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Jan 3, 2023
We cannot mark the returned usize as must use unfortunately. This is what triggered the bug in linux-loader: rust-vmm/linux-loader#125. The least we can do is to validate that when there are more bytes requested than what the reader has available, we do return the correct number of the read. Unfortunately, when this result is not used it can lead to bugs. Signed-off-by: Andreea Florescu <fandree@amazon.com>
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Summary of the PR
The ELF header contains offsets that the loader uses to find other structures. If those offsets are beyond the end of the file (or would go past the end of the file) it is essential to error out when attempting to read those. Using
Read::read_exact()permits this.Signed-off-by: Bo Chen chen.bo@intel.com
Co-authored-by: Rob Bradford robert.bradford@intel.com
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