CVE-2026-90107net/smc: free pending qentry in smc_llc_flow_stop() before memset

Official description

In the Linux kernel, the following vulnerability has been resolved: net/smc: free pending qentry in smc_llc_flow_stop() before memset smc_llc_flow_stop() resets a flow struct with a blind memset: spin_lock_bh(&lgr->llc_flow_lock); memset(flow, 0, sizeof(*flow)); flow->type = SMC_LLC_FLOW_NONE; spin_unlock_bh(&lgr->llc_flow_lock); If flow->qentry is non-NULL at this point the pointer is overwritten without the allocation being freed, leaking one kmalloc object. A late-arriving duplicate CONFIRM_LINK or ADD_LINK_CONT message can set flow->qentry after the legitimate message has been consumed by the waiter via smc_llc_flow_qentry_clr() (which NULLs the pointer but leaves flow->type non-zero) but before the flow completes and smc_llc_flow_stop() runs. In that window the duplicate is stashed into flow->qentry, and then lost when smc_llc_flow_stop() zeros the struct. Call smc_llc_flow_qentry_del() inside the lock before the memset. smc_llc_flow_qentry_del() already checks flow->qentry before freeing, so the normal case where no entry is pending is a no-op.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/8e3deb150a5237b672c4579e69a6deb02027dbed
• https://git.kernel.org/stable/c/11bc373ee6630709f0c2da2e7860c23d503c9e9d
• https://git.kernel.org/stable/c/032aec7d03c9102616b98fea74f8f7145e7f867c
• https://git.kernel.org/stable/c/957dba2b8b5aebfe09caa6a6b22b958079082eab
• https://git.kernel.org/stable/c/f03aa5d36ae3c4068a1c3885146be99aa7fd9307
• https://git.kernel.org/stable/c/0879ea157acc1ac6752f6fcb755d1f91a2359238
• https://git.kernel.org/stable/c/5ff429dd6725fa6c1e17a4ed0be8ab675f67a98b
• https://git.kernel.org/stable/c/5ee0ceddc7785c6dcf4a8107fef01f0414a354f4