Hello :crab: ,
we (Rust group @sslab-gatech) found a memory-safety/soundness issue in this crate while scanning Rust code on crates.io for potential vulnerabilities.
preamble_skipcount method creates an uninitialized buffer (buffer) and passes it to user-provided Read implementation. This is unsound, because it allows safe Rust code to exhibit an undefined behavior (read from uninitialized memory).
This part from the Read trait documentation explains the issue:
It is your responsibility to make sure that buf is initialized before calling read. Calling read with an uninitialized buf (of the kind one obtains via MaybeUninit<T>) is not safe, and can lead to undefined behavior.
Suggested Fix
It is safe to zero-initialize the newly allocated u8 buffer before read(), in order to prevent user-provided Read from accessing old contents of the newly allocated heap memory.
jblondin
commented
2 years ago
Hello :crab: , we (Rust group @sslab-gatech) found a memory-safety/soundness issue in this crate while scanning Rust code on crates.io for potential vulnerabilities.
Issue Description
https://github.com/jblondin/csv-sniffer/blob/d964e42e207975fcb42777297c988c2cf2a014a7/src/snip.rs#L7-L18
preamble_skipcountmethod creates an uninitialized buffer (buffer) and passes it to user-providedReadimplementation. This is unsound, because it allows safe Rust code to exhibit an undefined behavior (read from uninitialized memory).This part from the
Readtrait documentation explains the issue:Suggested Fix
It is safe to zero-initialize the newly allocated
u8buffer before read(), in order to prevent user-providedReadfrom accessing old contents of the newly allocated heap memory.Thank you for checking out this issue :+1: