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Fix memreader ub #150

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Merged
marti4d merged 1 commit into from
May 13, 2025
Merged

Fix memreader ub #150

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42 changes: 4 additions & 38 deletions src/linux/mem_reader.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -99,44 +99,10 @@ impl MemReader {
src: usize,
length: std::num::NonZeroUsize,
) -> Result<Vec<u8>, CopyFromProcessError> {
let length = length.into();
let layout =
std::alloc::Layout::array::<u8>(length).map_err(|_err| CopyFromProcessError {
child: self.pid.as_raw(),
src,
offset: 0,
length,
source: nix::errno::Errno::EINVAL,
})?;

// SAFETY: we've guaranteed the layout we're allocating is valid at this point
let output = unsafe {
let ptr = std::alloc::alloc(layout);
if ptr.is_null() {
return Err(CopyFromProcessError {
child: self.pid.as_raw(),
src,
offset: 0,
length,
source: nix::errno::Errno::ENOMEM,
});
}
std::slice::from_raw_parts_mut(ptr, length)
};

match self.read(src, output) {
Ok(read) => {
// SAFETY: we've filled initialized read bytes of our allocation block
unsafe { Ok(Vec::from_raw_parts(output.as_mut_ptr(), read, length)) }
}
Err(err) => {
// SAFETY: the pointer and layout are the same we just allocated
unsafe {
std::alloc::dealloc(output.as_mut_ptr(), layout);
}
Err(err)
}
}
let mut output = vec![0u8; length.into()];
let bytes_read = self.read(src, &mut output)?;
output.truncate(bytes_read);
Ok(output)
}

pub fn read(&mut self, src: usize, dst: &mut [u8]) -> Result<usize, CopyFromProcessError> {
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