CVE-2026-64594: Linux kernel · usb: gadget: f_fs: initialize reset_work at allocation time ffs_fs_kill_sb()
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.
Data as of 28 Oct 2026, 11:49 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +58
Exploitation evidence
Disclosed: evidence found.
CVE published 6 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and fixed versions include 5.15.0-1117.124~20.04.1 and later. Users should upgrade to these fixed kernel versions to resolve the issue. No additional mitigation is required beyond applying the official kernel updates.
Description
A vulnerability in the Linux kernel's USB gadget function filesystem (functionfs) subsystem was identified where the reset_work structure was not properly initialized before use. This could cause a kernel warning or instability when unmounting a functionfs instance. The issue arises because reset_work is only initialized in specific deactivation paths, but cancel_work_sync() is called unconditionally, potentially operating on an uninitialized work struct. The flaw has been fixed by initializing reset_work at allocation time to ensure it is always valid during the lifetime of the ffs_data structure.
References
- ubuntu.com/security/CVE-2026-64594 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64594 (opens in a new tab)
- git.kernel.org/linus/3137b243c93982fe3460335e12f9247739766e10 (opens in a new tab)
- git.kernel.org/stable/c/0de6ebbabfbbc9c28350283dc97d8a519d5c6dd7 (opens in a new tab)
- git.kernel.org/stable/c/3137b243c93982fe3460335e12f9247739766e10 (opens in a new tab)
- git.kernel.org/stable/c/69faa3779250df14f51d5084f938a99809546e52 (opens in a new tab)
- git.kernel.org/stable/c/7fe895e0a9651518c4fc082487da770ff9c14c7f (opens in a new tab)
- git.kernel.org/stable/c/ba1867999dbc4085e6d8c52ac5266005b8b2bf07 (opens in a new tab)
- git.kernel.org/stable/c/c36393b0d14e1e9783888f821ffe29381b8f46dc (opens in a new tab)
- git.kernel.org/stable/c/cb19e54ebe9baf3c3243083ade65c937339ccb7b (opens in a new tab)
- git.kernel.org/stable/c/d5631081be07f20e764d3cb5c98ac0a1004fba51 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)