CVE-2025-40315: Linux kernel · usb: gadget: f_fs: Fix epfile null pointer access after ep enable.
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 5.15.0-1103.110~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1103.110~20.04.1, 5.15.0-1110.119~20.04.1, 5.15.0-1114.123~20.04.1 +66
Exploitation evidence
Disclosed: evidence found.
CVE published 8 Dec 2025
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.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-14.14?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1007.7?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1008.8?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1007.7?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1007.7?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Fix epfile null pointer access after ep enable. A race condition occurs when ffs_func_eps_enable() runs concurrently with ffs_data_reset(). The ffs_data_clear() called in ffs_data_reset() sets ffs->epfiles to NULL before resetting ffs->eps_count to 0, leading to a NULL pointer dereference when accessing epfile->ep in ffs_func_eps_enable() after successful usb_ep_enable(). The ffs->epfiles pointer is set to NULL in both ffs_data_clear() and ffs_data_close() functions, and its modification is protected by the spinlock ffs->eps_lock. And the whole ffs_func_eps_enable() function is also protected by ffs->eps_lock. Thus, add NULL pointer handling for ffs->epfiles in the ffs_func_eps_enable() function to fix issues
References
- ubuntu.com/security/CVE-2025-40315 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-40315 (opens in a new tab)
- git.kernel.org/linus/cfd6f1a7b42f62523c96d9703ef32b0dbc495ba4 (opens in a new tab)
- git.kernel.org/stable/c/1c0dbd240be3f87cac321b14e17979b7e9cb6a8f (opens in a new tab)
- git.kernel.org/stable/c/30880e9df27332403dd638a82c27921134b3630b (opens in a new tab)
- git.kernel.org/stable/c/9ec40fba7357df2d36f4c2e2f3b9b1a4fba0a272 (opens in a new tab)
- git.kernel.org/stable/c/b00d2572c16e8e59e979960d3383c2ae9cebd195 (opens in a new tab)
- git.kernel.org/stable/c/c53e90563bc148e4e0ad09fe130ba2246d426ea6 (opens in a new tab)
- git.kernel.org/stable/c/cfd6f1a7b42f62523c96d9703ef32b0dbc495ba4 (opens in a new tab)
- git.kernel.org/stable/c/d62b808d5c68a931ad0849a00a5e3be3dd7e0019 (opens in a new tab)
- git.kernel.org/stable/c/fc1141a530dfc91f0ee19b7f422a2d24829584bc (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8030-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8048-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8095-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8100-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8095-2 (opens in a new tab)