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Fencer Vulns
medium 5.5

CVE-2023-53686 json

net/handshake: fix null-ptr-deref in handshake_nl_done_doit()

published 2025-10-07 13 mo ago modified 2026-10-28 11 d ago also EUVD-2025-31934

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 2%
public exploits
0
none known

Summary

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

net/handshake: fix null-ptr-deref in handshake_nl_done_doit()

We should not call trace_handshake_cmd_done_err() if socket lookup has failed.

Also we should call trace_handshake_cmd_done_err() before releasing the file, otherwise dereferencing sock->sk can return garbage.

This also reverts 7afc6d0a107f ("net/handshake: Fix uninitialized local variable")

Unable to handle kernel paging request at virtual address dfff800000000003 KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [dfff800000000003] address between user and kernel address ranges Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 5986 Comm: syz-executor292 Not tainted 6.5.0-rc7-syzkaller-gfe4469582053 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : handshake_nl_done_doit+0x198/0x9c8 net/handshake/netlink.c:193 lr : handshake_nl_done_doit+0x180/0x9c8 sp : ffff800096e37180 x29: ffff800096e37200 x28: 1ffff00012dc6e34 x27: dfff800000000000 x26: ffff800096e373d0 x25: 0000000000000000 x24: 00000000ffffffa8 x23: ffff800096e373f0 x22: 1ffff00012dc6e38 x21: 0000000000000000 x20: ffff800096e371c0 x19: 0000000000000018 x18: 0000000000000000 x17: 0000000000000000 x16: ffff800080516cc4 x15: 0000000000000001 x14: 1fffe0001b14aa3b x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000003 x8 : 0000000000000003 x7 : ffff800080afe47c x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800080a88078 x2 : 0000000000000001 x1 : 00000000ffffffa8 x0 : 0000000000000000 Call trace: handshake_nl_done_doit+0x198/0x9c8 net/handshake/netlink.c:193 genl_family_rcv_msg_doit net/netlink/genetlink.c:970 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1050 [inline] genl_rcv_msg+0x96c/0xc50 net/netlink/genetlink.c:1067 netlink_rcv_skb+0x214/0x3c4 net/netlink/af_netlink.c:2549 genl_rcv+0x38/0x50 net/netlink/genetlink.c:1078 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x660/0x8d4 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x834/0xb18 net/netlink/af_netlink.c:1914 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg net/socket.c:748 [inline] ____sys_sendmsg+0x56c/0x840 net/socket.c:2494 ___sys_sendmsg net/socket.c:2548 [inline] __sys_sendmsg+0x26c/0x33c net/socket.c:2577 __do_sys_sendmsg net/socket.c:2586 [inline] __se_sys_sendmsg net/socket.c:2584 [inline] __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2584 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 el0_svc+0x58/0x16c arch/arm64/kernel/entry-common.c:678 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 Code: 12800108 b90043e8 910062b3 d343fe68 (387b6908)

Patch / fix

  • Linux Linux 6.5.4, 6.6
  • linux Debian 14, Debian 13 6.5.6-1

debian advisories DEBIAN-CVE-2023-53686

  • kernel-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
  • kernel-syms-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
  • kernel-rt_debug Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
  • kernel-source-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-38.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-38.1
  • kernel-rt Real Time Module 15 SP7 6.4.0-150700.7.22.1
  • kernel-syms-rt Real Time Module 15 SP7 6.4.0-150700.7.22.1

suse advisories SUSE-SU-2025:4301-1SUSE-SU-2025:21052-1SUSE-SU-2025:21064-1SUSE-SU-2025:4141-1SUSE-SU-2025:4140-1SUSE-SU-2025:4132-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-53686 updated cvss 7.0

kernel: net/handshake: fix null-ptr-deref in handshake_nl_done_doit()

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.13% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

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