CVE Catalog

CVE-2026-74719

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel net/smc module, the smc_llc_event_handler() function lacks a check for an already pending qentry before storing a new one for CONFIRM_LINK and ADD_LINK_CONT. A malicious or buggy peer can send a second request, causing the pointer to be overwritten without freeing the previous allocation, leading to a memory leak (kmalloc-96).

Risk Assessment

Memory leak can be exploited for DoS attacks by exhausting memory resources, especially in environments with many SMC connections.

Recommendation

Apply the Linux kernel patch that adds the !flow->qentry guard in the CONFIRM_LINK/ADD_LINK_CONT branch so duplicates are dropped and freed instead of leaking.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: net/smc: fix qentry overwrite for CONFIRM_LINK and ADD_LINK_CONT in smc_llc_event_handler() The SMC_LLC_CONFIRM_LINK / SMC_LLC_ADD_LINK_CONT branch in smc_llc_event_handler() stores an incoming qentry into the local LLC flow without first checking whether a qentry is already pending. If a malicious or buggy peer sends a second CONFIRM_LINK or ADD_LINK_CONT request while a flow is active and flow->qentry is already set, smc_llc_flow_qentry_set() overwrites the pointer without freeing the previous allocation, leaking one kmalloc-96 object per spurious message. The sibling SMC_LLC_DELETE_LINK branch already has the correct !flow->qentry guard. Apply the same guard to the CONFIRM_LINK/ADD_LINK_CONT branch so that a duplicate message when qentry is already occupied falls through to break and is freed by the kfree(qentry) at the out: label, rather than silently leaking the existing allocation. The response direction (smc_llc_rx_response()) is unaffected: it already guards with flow->qentry at the equivalent site and drops duplicate responses correctly.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS