CVE-2025-21988

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

fs/netfs/read_collect: add to next->prev_donated

If multiple subrequests donate data to the same "next" request (depending on the subrequest completion order), each of them would overwrite the prev_donated field, causing data corruption and a BUG() crash ("Can't donate prior to front").

This vulnerability is rated as Moderate severity because exploitation requires local system access and is limited to causing a denial of service via a kernel crash, without compromising data confidentiality. Within Red Hat Enterprise Linux, the flaw affects the netfs subsystem when processing asynchronous network filesystem I/O operations. Earlier distributions such as RHEL 8 and 9 are unaffected because they lack the underlying read-collector code introduced in later upstream kernels.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.