CVE-2026-64065

/// Technical description

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

netfs: fix VM_BUG_ON_FOLIO() issue in netfs_write_begin() call

The multiple runs of generic/013 test-case is capable

to reproduce a kernel BUG at mm/filemap.c:1504 with

probability of 30%.

while true; do

sudo ./check generic/013

done

[ 9849.452376] page: refcount:3 mapcount:0 mapping:00000000e58ff252 index:0x10781 pfn:0x1c322

[ 9849.452412] memcg:ffff8881a1915800

[ 9849.452417] aops:ceph_aops ino:1000058db9e dentry name(?):"f9XXXXXX"

[ 9849.452432] flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)

[ 9849.452441] raw: 0017ffffc0000000 0000000000000000 dead000000000122 ffff88816110d248

[ 9849.452445] raw: 0000000000010781 0000000000000000 00000003ffffffff ffff8881a1915800

[ 9849.452447] page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio))

[ 9849.452474] ------------[ cut here ]------------

[ 9849.452476] kernel BUG at mm/filemap.c:1504!

[ 9849.478635] Oops: invalid opcode: 0000 [#1] SMP KASAN NO

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References