Message-ID: <2025122423-CVE-2023-54142-fd19@gregkh>
Date: Wed, 24 Dec 2025 14:07:39 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2023-54142: gtp: Fix use-after-free in __gtp_encap_destroy().

From: Greg Kroah-Hartman <gregkh@...nel.org>

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+0x59/0x70 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:186 [inline]
 slab_post_alloc_hook mm/slab.h:711 [inline]
 slab_alloc_node mm/slub.c:3451 [inline]
 slab_alloc mm/slub.c:3459 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3466 [inline]
 kmem_cache_alloc+0x16d/0x340 mm/slub.c:3475
 sk_prot_alloc+0x5f/0x280 net/core/sock.c:2073
 sk_alloc+0x34/0x6c0 net/core/sock.c:2132
 inet6_create net/ipv6/af_inet6.c:192 [inline]
 inet6_create+0x2c7/0xf20 net/ipv6/af_inet6.c:119
 __sock_create+0x2a1/0x530 net/socket.c:1535
 sock_create net/socket.c:1586 [inline]
 __sys_socket_create net/socket.c:1623 [inline]
 __sys_socket_create net/socket.c:1608 [inline]
 __sys_socket+0x137/0x250 net/socket.c:1651
 __do_sys_socket net/socket.c:1664 [inline]
 __se_sys_socket net/socket.c:1662 [inline]
 __x64_sys_socket+0x72/0xb0 net/socket.c:1662
 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

Freed by task 2401:
 kasan_save_stack+0x22/0x50 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:521
 ____kasan_slab_free mm/kasan/common.c:236 [inline]
 ____kasan_slab_free mm/kasan/common.c:200 [inline]
 __kasan_slab_free+0x10c/0x1b0 mm/kasan/common.c:244
 kasan_slab_free include/linux/kasan.h:162 [inline]
 slab_free_hook mm/slub.c:1781 [inline]
 slab_free_freelist_hook mm/slub.c:1807 [inline]
 slab_free mm/slub.c:3786 [inline]
 kmem_cache_free+0xb4/0x490 mm/slub.c:3808
 sk_prot_free net/core/sock.c:2113 [inline]
 __sk_destruct+0x500/0x720 net/core/sock.c:2207
 sk_destruct+0xc1/0xe0 net/core/sock.c:2222
 __sk_free+0xed/0x3d0 net/core/sock.c:2233
 sk_free+0x7c/0xa0 net/core/sock.c:2244
 sock_put include/net/sock.h:1981 [inline]
 __gtp_encap_destroy+0x165/0x1b0 drivers/net/gtp.c:634
 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

The buggy address belongs to the object at ffff88800dbef300
 which belongs to the cache UDPv6 of size 1344
The buggy address is located 152 bytes inside of
 freed 1344-byte region [ffff88800dbef300, ffff88800dbef840)

The buggy address belongs to the physical page:
page:00000000d31bfed5 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88800dbeed40 pfn:0xdbe8
head:00000000d31bfed5 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888008ee0801
flags: 0x100000000010200(slab|head|node=0|zone=1)
page_type: 0xffffffff()
raw: 0100000000010200 ffff88800c7a3000 dead000000000122 0000000000000000
raw: ffff88800dbeed40 0000000080160015 00000001ffffffff ffff888008ee0801
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88800dbef280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88800dbef300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88800dbef380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88800dbef400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88800dbef480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

The Linux kernel CVE team has assigned CVE-2023-54142 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 4.14.135 with commit 01f3c64e405ab3d25887d080a103ad76f30661d2 and fixed in 4.14.322 with commit d38039697184aacff1cf576e14ef583112fdefef
	Issue introduced in 4.19.61 with commit e117a04133c673cc54292e12086a8177cd9bd4a4 and fixed in 4.19.291 with commit e5aa6d829831a55a693dbaeb58f8d22ba7f2b3e6
	Issue introduced in 5.3 with commit e198987e7dd7d3645a53875151cd6f8fc425b706 and fixed in 5.4.251 with commit 9c9662e2512b5e4ee7b03108802c5222e0fa77a4
	Issue introduced in 5.3 with commit e198987e7dd7d3645a53875151cd6f8fc425b706 and fixed in 5.10.188 with commit bccc7ace12e69dee4684a3bb4b69737972e570d6
	Issue introduced in 5.3 with commit e198987e7dd7d3645a53875151cd6f8fc425b706 and fixed in 5.15.121 with commit ebd6d2077a083329110695a996c00e8ca94bc640
	Issue introduced in 5.3 with commit e198987e7dd7d3645a53875151cd6f8fc425b706 and fixed in 6.1.39 with commit 17d6b6354f0025b7c10a56da783fd0cbb3819c5d
	Issue introduced in 5.3 with commit e198987e7dd7d3645a53875151cd6f8fc425b706 and fixed in 6.3.13 with commit dae6095bdb24f537b4798ffd9201515b97bac94e
	Issue introduced in 5.3 with commit e198987e7dd7d3645a53875151cd6f8fc425b706 and fixed in 6.4.4 with commit 58fa341327fdb4bdf92597fd8796a9abc8d20ea3
	Issue introduced in 5.3 with commit e198987e7dd7d3645a53875151cd6f8fc425b706 and fixed in 6.5 with commit ce3aee7114c575fab32a5e9e939d4bbb3dcca79f
	Issue introduced in 5.1.20 with commit bf75202df8e473d4ee914894542f213158066d8b
	Issue introduced in 5.2.3 with commit 76357f65f18f180f44ccbbbf713461881d0ab219

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2023-54142
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/net/gtp.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/d38039697184aacff1cf576e14ef583112fdefef
	https://git.kernel.org/stable/c/e5aa6d829831a55a693dbaeb58f8d22ba7f2b3e6
	https://git.kernel.org/stable/c/9c9662e2512b5e4ee7b03108802c5222e0fa77a4
	https://git.kernel.org/stable/c/bccc7ace12e69dee4684a3bb4b69737972e570d6
	https://git.kernel.org/stable/c/ebd6d2077a083329110695a996c00e8ca94bc640
	https://git.kernel.org/stable/c/17d6b6354f0025b7c10a56da783fd0cbb3819c5d
	https://git.kernel.org/stable/c/dae6095bdb24f537b4798ffd9201515b97bac94e
	https://git.kernel.org/stable/c/58fa341327fdb4bdf92597fd8796a9abc8d20ea3
	https://git.kernel.org/stable/c/ce3aee7114c575fab32a5e9e939d4bbb3dcca79f

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