CVE-2026-80851

What the bug is

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 path, and keep the RCU read-side section around the complete PDP context use in the DELPDP path.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

drivers/net/gtp.c

What this is

GTP (GPRS Tunneling Protocol)MAINTAINERS section matched on drivers/net/gtp.c · osmocom-net-gprs@lists.osmocom.org · Maintained

Kernel module

gtp

Check it on the machine

grep -w CONFIG_GTP /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

lsmod | grep -w gtp

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

• bookworm, trixie, forky, sid, bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/cloud-arm64

M

a module where it is built at all; some flavours do not build it

Build switch

CONFIG_GTP

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-09-04 (44 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.17%, higher than 6.2% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/net

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
4.7	6.6.158	b4ac2a5ce5a9
4.7	6.12.108	5f77ddb27563
4.7	6.18.49	3d950e98f74a
4.7	7.1.13	6df4f05bc299
4.7	7.2.3	1e995498d297
4.7	7.3	498386b6d402

Debian advisories