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

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---

CVSS

7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness (CWE)

Not given

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

Linux

NVD analysis

Deferred

Record last updated

Aug 5, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

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