CVE-2026-99032
Received
Received - Intake
Use-After-Free in Linux Kernel SMC Socket
Vulnerability report for CVE-2026-99032, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-23
Last updated on: 2026-10-23
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
net/smc: protect clcsock lifetime in smc_getname
smc_getname() dereferences smc->clcsock without holding
clcsock_release_lock. Link-group termination can release the CLC socket
through smc_close_active_abort() while the SMC socket is still open,
for example after shutdown(SHUT_WR).
A getsockname() caller can load smc->clcsock, then the termination worker
can clear the pointer and call sock_release() before the caller accesses
clcsock->ops or invokes getname(). This causes a use-after-free; if the
worker clears the pointer before the load, it causes a NULL dereference.
The syscall's file reference keeps the SMC socket alive but does not
prevent asynchronous release of its CLC socket.
KASAN reported the following with test-only timing instrumentation:
BUG: KASAN: slab-use-after-free in smc_getname+0x19e/0x1b0
Read of size 8 at addr ffff888109abb4e0 by task poc/103
Call Trace:
smc_getname+0x19e/0x1b0
do_getsockname+0xe5/0x170
__sys_getsockname+0x8c/0x100
Allocated by task 95:
sock_alloc_inode+0x1e/0x280
sock_alloc+0x3d/0x240
__sock_create+0x7e/0x430
smc_create+0x121/0x240
Freed by task 0:
kmem_cache_free+0xcc/0x340
rcu_core+0x50a/0x1850
Last potentially related work creation:
evict+0x446/0x6c0
smc_clcsock_release+0xa8/0xd0
smc_close_active_abort+0x26a/0x3a0
__smc_lgr_terminate.part.0+0x137/0x2e0
Hold clcsock_release_lock across the pointer check and the getname()
callback to serialize with smc_clcsock_release(). Return -EBADF if the
CLC socket has already been released, preserving the existing peer
state check and the callback's return value otherwise.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | b03faa1fafc8018295401dc558bdc76362d860a4 |
| Linux | Linux | b03faa1fafc8018295401dc558bdc76362d860a4 |
| Linux | Linux | b03faa1fafc8018295401dc558bdc76362d860a4 |
| Linux | Linux | b03faa1fafc8018295401dc558bdc76362d860a4 |
| Linux | Linux | b03faa1fafc8018295401dc558bdc76362d860a4 |
| Linux | Linux | 0b6153d04c96a1d4b6284692386aa21d04d7956c |
| Linux | Linux | 4.19.299 |
| Linux | Linux | 5.1 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
