Linux Kernel up to 6.12.109/6.18.51/7.2.5 f_fs func_fs.c ffs_dmabuf_transfer uninitialized pointer

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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8.6$0-$5k0.39-

Summaryinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 6.12.109/6.18.51/7.2.5. This affects the function ffs_dmabuf_transfer of the file drivers/usb/gadget/func_fs.c of the component f_fs. Executing a manipulation can lead to uninitialized pointer. This vulnerability is handled as CVE-2026-93121. The attack can be executed remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as very critical was found in Linux Kernel up to 6.12.109/6.18.51/7.2.5. This vulnerability affects the function ffs_dmabuf_transfer of the file drivers/usb/gadget/func_fs.c of the component f_fs. The manipulation with an unknown input leads to a uninitialized pointer vulnerability. The CWE definition for the vulnerability is CWE-824. The product accesses or uses a pointer that has not been initialized. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Fix fence cleanup in ffs_dmabuf_transfer() error paths The error paths for endpoint-disabled (ESHUTDOWN) and request-allocation failure (ENOMEM) in ffs_dmabuf_transfer() jump to err_fence_put which calls dma_fence_put() on the fence. However, at that point the fence has only been kmalloc'd — dma_fence_init() has not been called yet, so the refcount and the fence ops are uninitialized. Calling dma_fence_put() on such an object leads to undefined behavior. Use kfree() instead, since the fence is just a plain allocation at this stage, and rename the label to err_fence_free to reflect the actual cleanup action.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-93121 since 09/17/2026. The exploitation appears to be easy. The attack can be initiated remotely. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 09/17/2026).

Upgrading to version 6.12.110, 6.18.52, 7.2.6 or 7.3-rc1 eliminates this vulnerability. Applying the patch be539138d9a187af3b884525a395db10797c64f1/5fd8baacc7dc477df9cac61b45491840247a9b1e/58952c83dfe6ea3294a74734d2d1018c1120779a/621707dc67c9846fd876d7579ec951d92aa033f1 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.0
VulDB Meta Temp Score: 8.6

VulDB Base Score: 9.0
VulDB Temp Score: 8.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Uninitialized pointer
CWE: CWE-824 / CWE-908
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.110/6.18.52/7.2.6/7.3-rc1
Patch: be539138d9a187af3b884525a395db10797c64f1/5fd8baacc7dc477df9cac61b45491840247a9b1e/58952c83dfe6ea3294a74734d2d1018c1120779a/621707dc67c9846fd876d7579ec951d92aa033f1

Timelineinfo

09/17/2026 Advisory disclosed
09/17/2026 +0 days CVE reserved
09/17/2026 +0 days VulDB entry created
09/17/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-93121 (🔒)
GCVE (CVE): GCVE-0-2026-93121
GCVE (VulDB): GCVE-100-407206

Entryinfo

Created: 09/17/2026 23:47
Changes: 09/17/2026 23:47 (60)
Complete: 🔍
Cache ID: 216::103

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