CVE-2026-90107 net/smc: free pending qentry in smc_llc_flow_stop() before memset
A memory leak in the Linux kernel SMC protocol allows remote attackers to exhaust kernel memory via crafted network messages, causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90107?
CVE-2026-90107 is a memory corruption vulnerability in Linux, published on 17 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Which versions are affected by CVE-2026-90107?
How do I fix CVE-2026-90107?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-90107 being exploited?
There is no known exploitation of CVE-2026-90107 in the wild and no public exploit code.
Sources
Also known as AZL-102797, BELL-CVE-2026-90107, DEBIAN-CVE-2026-90107, GHSA-mw8r-cvfc-f297, UBUNTU-CVE-2026-90107.