CVE-2026-64216
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk37th percentile - higher than 37% of all known CVEs
Summary
In the Linux kernel's netfs subsystem, a use-after-free vulnerability was found in netfs_unlock_abandoned_read_pages(). The function accesses the folio index after clearing the NETFS_RREQ_IN_PROGRESS flag, potentially leading to dereference of freed memory.
Risk Assessment
Risk includes system crash or potential arbitrary code execution by an attacker due to accessing freed memory.
Recommendation
Update the Linux kernel to a version with the fix that stores the folio pointer instead of the index.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages() netfs_unlock_abandoned_read_pages(rreq) accesses the index of the folios it is wanting to unlock and compares that to rreq->no_unlock_folio so that it doesn't unlock a folio being read for netfs_perform_write() or netfs_write_begin(). However, given that netfs_unlock_abandoned_read_pages() is called _after_ NETFS_RREQ_IN_PROGRESS is cleared, the one folio that it's not allowed to dereference is the one specified by ->no_unlock_folio as ownership immediately reverts to the caller. Fix this by storing the folio pointer instead and using that rather than the index. Also fix netfs_unlock_read_folio() where the same applies.