CVE-2026-93121: Linux kernel · usb: gadget: f_fs: Fix fence cleanup in ffs_dmabuf_transfer() error paths
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.0 High · fixed in be539138d9a187af3b884525a395db10797c64f1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in be539138d9a187af3b884525a395db10797c64f1, 621707dc67c9846fd876d7579ec951d92aa033f1, 58952c83dfe6ea3294a74734d2d1018c1120779a +1
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 17 Sep 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 Linux kernel to be539138d9a187af3b884525a395db10797c64f1, 621707dc67c9846fd876d7579ec951d92aa033f1, 58952c83dfe6ea3294a74734d2d1018c1120779a or 5fd8baacc7dc477df9cac61b45491840247a9b1e.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available and has been applied in Linux kernel version 6.9 and specific commits. Users and administrators should update to the fixed kernel versions to remediate this vulnerability. No additional mitigation steps are indicated beyond applying the official patch.
Description
CVE-2026-93121 is a high-severity vulnerability in the Linux kernel's USB gadget function f_fs. It involves improper cleanup of a dma_fence object in error paths of the ffs_dmabuf_transfer() function. Specifically, dma_fence_put() was called on a fence that had only been allocated but not fully initialized, leading to undefined behavior. This issue has been fixed by replacing dma_fence_put() with kfree() for cleanup in these error cases.
References
- git.kernel.org/stable/c/be539138d9a187af3b884525a395db10797c64f1 (opens in a new tab)
- git.kernel.org/stable/c/5fd8baacc7dc477df9cac61b45491840247a9b1e (opens in a new tab)
- git.kernel.org/stable/c/58952c83dfe6ea3294a74734d2d1018c1120779a (opens in a new tab)
- git.kernel.org/stable/c/621707dc67c9846fd876d7579ec951d92aa033f1 (opens in a new tab)