# CVE-2023-54142: gtp: Fix use-after-free in __gtp_encap_destroy().

> A use-after-free vulnerability in the Linux kernel's GTP module allows attackers to potentially execute arbitrary code or escalate privileges.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Dec 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2023-54142, DEBIAN-CVE-2023-54142, GHSA-frp2-qrfx-2m63, UBUNTU-CVE-2023-54142

## What is CVE-2023-54142?

CVE-2023-54142 is a high-severity use after free vulnerability in Linux, published on 24 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

gtp: Fix use-after-free in __gtp_encap_destroy().

syzkaller reported use-after-free in __gtp_encap_destroy(). [0]

It shows the same process freed sk and touched it illegally.

Commit e198987e7dd7 ("gtp: fix suspicious RCU usage") added lock_sock()
and release_sock() in __gtp_encap_destroy() to protect sk->sk_user_data,
but release_sock() is called after sock_put() releases the last refcnt.

[0]:
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:541 [inline]
BUG: KASAN: slab-use-after-free in queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
BUG: KASAN: slab-use-after-free in do_raw_spin_lock include/linux/spinlock.h:186 [inline]
BUG: KASAN: slab-use-after-free in __raw_spin_lock_bh include/linux/spinlock_api_smp.h:127 [inline]
BUG: KASAN: slab-use-after-free in _raw_spin_lock_bh+0x75/0xe0 kernel/locking/spinlock.c:178
Write of size 4 at addr ffff88800dbef398 by task syz-executor.2/2401

CPU: 1 PID: 2401 Comm: syz-executor.2 Not tainted 6.4.0-rc5-01219-gfa0e21fa4443 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x72/0xa0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:351 [inline]
 print_report+0xcc/0x620 mm/kasan/report.c:462
 kasan_report+0xb2/0xe0 mm/kasan/report.c:572
 check_region_inline mm/kasan/generic.c:181 [inline]
 kasan_check_range+0x39/0x1c0 mm/kasan/generic.c:187
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:541 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
 do_raw_spin_lock include/linux/spinlock.h:186 [inline]
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:127 [inline]
 _raw_spin_lock_bh+0x75/0xe0 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:355 [inline]
 release_sock+0x1f/0x1a0 net/core/sock.c:3526
 gtp_encap_disable_sock drivers/net/gtp.c:651 [inline]
 gtp_encap_disable+0xb9/0x220 drivers/net/gtp.c:664
 gtp_dev_uninit+0x19/0x50 drivers/net/gtp.c:728
 unregister_netdevice_many_notify+0x97e/0x1520 net/core/dev.c:10841
 rtnl_delete_link net/core/rtnetlink.c:3216 [inline]
 rtnl_dellink+0x3c0/0xb30 net/core/rtnetlink.c:3268
 rtnetlink_rcv_msg+0x450/0xb10 net/core/rtnetlink.c:6423
 netlink_rcv_skb+0x15d/0x450 net/netlink/af_netlink.c:2548
 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
 netlink_unicast+0x700/0x930 net/netlink/af_netlink.c:1365
 netlink_sendmsg+0x91c/0xe30 net/netlink/af_netlink.c:1913
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg+0x1b7/0x200 net/socket.c:747
 ____sys_sendmsg+0x75a/0x990 net/socket.c:2493
 ___sys_sendmsg+0x11d/0x1c0 net/socket.c:2547
 __sys_sendmsg+0xfe/0x1d0 net/socket.c:2576
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3f/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7f1168b1fe5d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 73 9f 1b 00 f7 d8 64 89 01 48
RSP: 002b:00007f1167edccc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004bbf80 RCX: 00007f1168b1fe5d
RDX: 0000000000000000 RSI: 00000000200002c0 RDI: 0000000000000003
RBP: 00000000004bbf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f1168b80530 R15: 0000000000000000
 </TASK>

Allocated by task 1483:
 kasan_save_stack+0x22/0x50 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 __kasan_slab_alloc+0x
---truncated---

## Which versions are affected by CVE-2023-54142?


## How do I fix CVE-2023-54142?

Apply the vendor's patch.

## Is CVE-2023-54142 being exploited?

There is no known exploitation of CVE-2023-54142 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-54142 and fix it if it is affected.

What it is: CVE-2023-54142 is a high-severity use after free vulnerability in Linux, published on 24 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-54142 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-54142/ (Markdown: https://insights.sbomify.com/CVE-2023-54142/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-54142
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-54142
- OSV: https://osv.dev/vulnerability/CVE-2023-54142

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-54142/
Summaries are generated and may contain mistakes; the official description above is the record.