CVE-2026-64062 netfs: Fix potential deadlock in write-through mode

What is CVE-2026-64062?

CVE-2026-64062 is a medium-severity vulnerability in Linux kernel, published on 19 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

netfs: Fix potential deadlock in write-through mode

Fix netfs_advance_writethrough() to always unlock the supplied folio and to mark it dirty if it isn't yet written to the end. Unfortunately, it can't be marked for writeback until the folio is done with as that may cause a deadlock against mmapped reads and writes.

Even though it has been marked dirty, premature writeback can't occur as the caller is holding both inode->i_rwsem (which will prevent concurrent truncation, fallocation, DIO and other writes) and ictx->wb_lock (which will cause flushing to wait and writeback to skip or wait).

Note that this may be easier to deal with once the queuing of folios is split from the generation of subrequests.

Weakness: CWE-667

Which versions are affected by CVE-2026-64062?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-64062?

Apply the vendor's patch.

Is CVE-2026-64062 being exploited?

There is no known exploitation of CVE-2026-64062 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2026-64062, DEBIAN-CVE-2026-64062, GHSA-pw37-pjm5-88jp, UBUNTU-CVE-2026-64062.