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()… (CVE-2026-98559)

The Linux kernel vulnerability CVE-2026-98559 involves a use-after-free condition in the net/smc subsystem. Specifically, smcr_port_err() traverses the smc_lgr_list.list without acquiring the smc_lgr_list.lock, which allows a concurrent smc_lgr_terminate_sched() to free an lgr object while it is still being dereferenced. The vulnerability was addressed by ensuring the smc_lgr_list.lock is held throughout the traversal and modifying smc_ib_gid_check() to call smcr_port_err() only after releasing the lock.

This vulnerability could lead to use-after-free memory access within the Linux kernel's net/smc subsystem, potentially causing kernel crashes or undefined behavior. No specific exploitation details or active exploits are reported.

A fix has been implemented in the Linux kernel source to hold the smc_lgr_list.lock during list traversal in smcr_port_err() and to adjust the call sequence in smc_ib_gid_check(). Users should update to the patched kernel versions once available. Patch status is not explicitly confirmed in the provided data; check the vendor advisory for current remediation guidance.