Bug 2555033 (CVE-2026-98559)

Summary: CVE-2026-98559 kernel: net/smc: fix UAF on lgr list traversal in smcr_port_err()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's Shared Memory Communications (SMC) subsystem. When processing port errors, the kernel traverses active link groups without holding the appropriate lock, allowing a concurrent termination event to free memory while it is still in use. An attacker capable of inducing these concurrent network events could exploit this race condition to trigger a use-after-free flaw, leading to a Denial of Service (DoS) via a system crash.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-10-18 15:40:31 UTC 
In the Linux kernel, the following vulnerability has been resolved:

net/smc: fix UAF on lgr list traversal in smcr_port_err()

smcr_port_err() traverses smc_lgr_list.list without holding
smc_lgr_list.lock, allowing a concurrent smc_lgr_terminate_sched()
to free an lgr while it is still being dereferenced.

Hold smc_lgr_list.lock across the traversal. Update
smc_ib_gid_check() to call smcr_port_err() after releasing the lock.