RFR: 8329961: Buffer overflow in os::Linux::kernel_version [v4]

[Thomas Stuefe]

On Wed, 10 Apr 2024 13:47:14 GMT, Johan Sjölen <jsjolen at openjdk.org> wrote:

>> Hi,
>> 
>> There was a bug in the original implementation of `os::Linux::kernel_version` which this PR fixes. Namely, the comparison `walker != nullptr` is wrong, the intended comparison was `*walker != '\0'` or `walker[0] != '\0'`. This means that if a bad/unexpected version string is encountered the `walker` would read past the string.
>> 
>> We fix this by applying the correct comparison and adding some basic tests.
>> 
>> @luhenry , @robehn. You attempted to create automatic backport branches on this in the original PR, can you check whether this fix also needs to be backported to the mentioned versions? The original PR link is this: https://github.com/openjdk/jdk/pull/17889
>
> Johan Sjölen has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Style
>  - Convert to sscanf

neat

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Marked as reviewed by stuefe (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/18697#pullrequestreview-1991860572