Linux Kernel up to 6.12.108/6.18.49/7.2.3 SMC Connection net/smc/conn.c smc_conn_free killed/sndbuf_desc use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$5k-$25k0.42+

Summaryinfo

A vulnerability labeled as very critical has been found in Linux Kernel up to 6.12.108/6.18.49/7.2.3. This affects the function smc_conn_free of the file net/smc/conn.c of the component SMC Connection. Such manipulation of the argument killed/sndbuf_desc leads to use after free. This vulnerability is traded as CVE-2026-80979. The attack may be launched remotely. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 6.12.108/6.18.49/7.2.3. Affected by this issue is the function smc_conn_free of the file net/smc/conn.c of the component SMC Connection. The manipulation of the argument killed/sndbuf_desc with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: net/smc: unregister the connection before draining the rx tasklet smc_conn_free() calls smc_ism_unset_conn() only while the link group is still on its device list, and never sets conn->killed. smc_lgr_terminate_sched() unlinks the group immediately and defers killing its connections to a work item, so a connection freed in that window keeps its smcd->conn[] slot with both gates in smcd_handle_irq() open, and the device can re-arm the receive tasklet after tasklet_kill() has returned. On the DMB-nocopy path the ghost send buffer is freed right after that drain, so the re-armed tasklet dereferences it. Unregister unconditionally and drain before the detach at both teardown sites, mirroring rmb_desc, which smc_buf_unuse() releases after the drain. Clear conn->sndbuf_desc before freeing it as well, so a reader that samples the pointer cannot get one that is already freed.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-80979 since 08/26/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 09/12/2026).

Upgrading to version 6.12.109, 6.18.50, 7.2.4 or 7.3-rc1 eliminates this vulnerability. Applying the patch b4d540ac95cd35c6ebab6afb7eae2bcac7b277a5/5bd8b764a610b6b6bc0c4d3d01652747f6e0b5c3/b74d313567dfc1b7e56629ddbad04e728686f235/36cdf5d48ca191dcd71c28cadbe0981b1d25318d is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
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: Use after free
CWE: CWE-416 / CWE-119
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 6.12.109/6.18.50/7.2.4/7.3-rc1
Patch: b4d540ac95cd35c6ebab6afb7eae2bcac7b277a5/5bd8b764a610b6b6bc0c4d3d01652747f6e0b5c3/b74d313567dfc1b7e56629ddbad04e728686f235/36cdf5d48ca191dcd71c28cadbe0981b1d25318d

Timelineinfo

08/26/2026 CVE reserved
09/11/2026 +16 days VulDB entry created
09/12/2026 +0 days Advisory disclosed
09/12/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-80979 (🔒)
GCVE (CVE): GCVE-0-2026-80979
GCVE (VulDB): GCVE-100-402734

Entryinfo

Created: 09/12/2026 00:06
Changes: 09/12/2026 00:06 (61)
Complete: 🔍
Cache ID: 216::103

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