CVE-2026-80851

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

gtp: serialize PDP context updates

PDP contexts can be deleted through GTP_CMD_DELPDP or while the GTP

network device is being unregistered. The latter is serialized by RTNL,

but the generic-netlink delete path only holds RCU.

Running both paths concurrently can therefore make both paths delete the

same PDP context. The issue was found through static analysis and

reproduced on a KASAN-enabled kernel by a simple two-thread program

racing GTP_CMD_DELPDP against RTM_DELLINK:

Oops: general protection fault, probably for non-canonical address

KASAN: maybe wild-memory-access in range

[0xdead000000000120-0xdead000000000127]

RIP: gtp_genl_del_pdp+0x1c1/0x420 [gtp]

RBP: dead000000000122

The second deletion dereferenced the poisoned hlist pprev pointer.

Serialize gtp_pdp_add(), gtp_genl_del_pdp(), and gtp_dellink() with a

shared mutex. Keep the mutex held until the final use of a PDP context in

the NEWPDP

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References