CVE-2026-64004: net/iucv: fix locking in .getsockopt
In the Linux kernel, the following vulnerability has been resolved:
net/iucv: fix locking in .getsockopt
Mirror iucvsocksetsockopt() and wrap the whole switch in locksock()/releasesock(). The pre-existing SOMSGLIMIT-only lock becomes redundant and is removed.
Any AFIUCV HIPER user can potentially crash the kernel by racing recvmsg() with getsockopt(SOMSGSIZE): the SOMSGSIZE arm dereferences iucv->hsdev->mtu after iucvsockclose() (called from the racing recvmsg()) has set hsdev to NULL, producing a NULL pointer dereference oops.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-64004?
The severity of CVE-2026-64004 is rated at 57, indicating a moderate risk level.
How do I fix CVE-2026-64004?
To fix CVE-2026-64004, ensure that you are running the latest version of the Linux kernel that includes the security patches addressing this vulnerability.
What systems are affected by CVE-2026-64004?
CVE-2026-64004 affects Linux kernel implementations that utilize the iucv networking stack.
What type of vulnerability is CVE-2026-64004 classified as?
CVE-2026-64004 is classified as a Null Pointer Dereference vulnerability.
Can CVE-2026-64004 be exploited remotely?
Yes, CVE-2026-64004 can potentially be exploited by users of the AF_IUCV HIPER protocol.