CVE-2024-57839

In the Linux kernel, the following vulnerability has been resolved:

Revert readahead: properly shorten readahead when falling back to do_page_cache_ra()

This reverts commit 7c877586da3178974a8a94577b6045a48377ff25.

Anders and Philippe have reported that recent kernels occasionally hang when used with NFS in readahead code. The problem has been bisected to 7c877586da3 (readahead: properly shorten readahead when falling back to do_page_cache_ra()). The cause of the problem is that ra->size can be shrunk by read_pages() call and subsequently we end up calling do_page_cache_ra() with negative (read huge positive) number of pages. Lets revert 7c877586da3 for now until we can find a proper way how the logic in read_pages() and page_cache_ra_order() can coexist. This can lead to reduced readahead throughput due to readahead window confusion but thats better than outright hangs.

Affected Software

References

• https://git.kernel.org/stable/c/85351e4941a253e4c50fb7048bfc19b60b4ec44b
• https://git.kernel.org/stable/c/a220d6b95b1ae12c7626283d7609f0a1438e6437