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Fencer Vulns
no cvss —

CVE-2023-53863 json

netlink: do not hard code device address lenth in fdb dumps

published 2025-12-09 11 mo ago modified 2026-06-17 4 mo ago also EUVD-2023-60133

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 18%
public exploits
0
none known

Summary

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

netlink: do not hard code device address lenth in fdb dumps

syzbot reports that some netdev devices do not have a six bytes address [1]

Replace ETH_ALEN by dev->addr_len.

[1] (Case of a device where dev->addr_len = 4)

BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline] BUG: KMSAN: kernel-infoleak in copyout+0xb8/0x100 lib/iov_iter.c:169 instrument_copy_to_user include/linux/instrumented.h:114 [inline] copyout+0xb8/0x100 lib/iov_iter.c:169 _copy_to_iter+0x6d8/0x1d00 lib/iov_iter.c:536 copy_to_iter include/linux/uio.h:206 [inline] simple_copy_to_iter+0x68/0xa0 net/core/datagram.c:513 __skb_datagram_iter+0x123/0xdc0 net/core/datagram.c:419 skb_copy_datagram_iter+0x5c/0x200 net/core/datagram.c:527 skb_copy_datagram_msg include/linux/skbuff.h:3960 [inline] netlink_recvmsg+0x4ae/0x15a0 net/netlink/af_netlink.c:1970 sock_recvmsg_nosec net/socket.c:1019 [inline] sock_recvmsg net/socket.c:1040 [inline] ____sys_recvmsg+0x283/0x7f0 net/socket.c:2722 ___sys_recvmsg+0x223/0x840 net/socket.c:2764 do_recvmmsg+0x4f9/0xfd0 net/socket.c:2858 __sys_recvmmsg net/socket.c:2937 [inline] __do_sys_recvmmsg net/socket.c:2960 [inline] __se_sys_recvmmsg net/socket.c:2953 [inline] __x64_sys_recvmmsg+0x397/0x490 net/socket.c:2953 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Uninit was stored to memory at: __nla_put lib/nlattr.c:1009 [inline] nla_put+0x1c6/0x230 lib/nlattr.c:1067 nlmsg_populate_fdb_fill+0x2b8/0x600 net/core/rtnetlink.c:4071 nlmsg_populate_fdb net/core/rtnetlink.c:4418 [inline] ndo_dflt_fdb_dump+0x616/0x840 net/core/rtnetlink.c:4456 rtnl_fdb_dump+0x14ff/0x1fc0 net/core/rtnetlink.c:4629 netlink_dump+0x9d1/0x1310 net/netlink/af_netlink.c:2268 netlink_recvmsg+0xc5c/0x15a0 net/netlink/af_netlink.c:1995 sock_recvmsg_nosec+0x7a/0x120 net/socket.c:1019 ____sys_recvmsg+0x664/0x7f0 net/socket.c:2720 ___sys_recvmsg+0x223/0x840 net/socket.c:2764 do_recvmmsg+0x4f9/0xfd0 net/socket.c:2858 __sys_recvmmsg net/socket.c:2937 [inline] __do_sys_recvmmsg net/socket.c:2960 [inline] __se_sys_recvmmsg net/socket.c:2953 [inline] __x64_sys_recvmmsg+0x397/0x490 net/socket.c:2953 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Uninit was created at: slab_post_alloc_hook+0x12d/0xb60 mm/slab.h:716 slab_alloc_node mm/slub.c:3451 [inline] __kmem_cache_alloc_node+0x4ff/0x8b0 mm/slub.c:3490 kmalloc_trace+0x51/0x200 mm/slab_common.c:1057 kmalloc include/linux/slab.h:559 [inline] __hw_addr_create net/core/dev_addr_lists.c:60 [inline] __hw_addr_add_ex+0x2e5/0x9e0 net/core/dev_addr_lists.c:118 __dev_mc_add net/core/dev_addr_lists.c:867 [inline] dev_mc_add+0x9a/0x130 net/core/dev_addr_lists.c:885 igmp6_group_added+0x267/0xbc0 net/ipv6/mcast.c:680 ipv6_mc_up+0x296/0x3b0 net/ipv6/mcast.c:2754 ipv6_mc_remap+0x1e/0x30 net/ipv6/mcast.c:2708 addrconf_type_change net/ipv6/addrconf.c:3731 [inline] addrconf_notify+0x4d3/0x1d90 net/ipv6/addrconf.c:3699 notifier_call_chain kernel/notifier.c:93 [inline] raw_notifier_call_chain+0xe4/0x430 kernel/notifier.c:461 call_netdevice_notifiers_info net/core/dev.c:1935 [inline] call_netdevice_notifiers_extack net/core/dev.c:1973 [inline] call_netdevice_notifiers+0x1ee/0x2d0 net/core/dev.c:1987 bond_enslave+0xccd/0x53f0 drivers/net/bonding/bond_main.c:1906 do_set_master net/core/rtnetlink.c:2626 [inline] rtnl_newlink_create net/core/rtnetlink.c:3460 [inline] __rtnl_newlink net/core/rtnetlink.c:3660 [inline] rtnl_newlink+0x378c/0x40e0 net/core/rtnetlink.c:3673 rtnetlink_rcv_msg+0x16a6/0x1840 net/core/rtnetlink.c:6395 netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2546 rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6413 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0xf28/0x1230 net/netlink/af_ ---truncated---

Patch / fix

  • Linux Linux 4.14.322, 4.19.291, 5.4.251, 5.10.188, 5.15.121, 6.1.39, 6.3.13, 6.4.4, 6.5
  • linux Debian 12 6.1.52-1
  • linux Debian 14, Debian 13 6.4.4-1

debian advisories DEBIAN-CVE-2023-53863

  • linux Ubuntu 20.04 LTS 5.4.0-166.183
  • linux Ubuntu 22.04 LTS 5.15.0-86.96
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1113.123
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1047.52
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1117.126
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1044.52
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1044.49
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1060.65

ubuntu advisories UBUNTU-CVE-2023-53863

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 9 5.14.0-427.13.1.el9_4
  • rv RHEL 9 5.14.0-427.13.1.el9_4
  • perf RHEL 9 5.14.0-427.13.1.el9_4
  • rtla RHEL 9 5.14.0-427.13.1.el9_4
  • bpftool RHEL 9 7.3.0-427.13.1.el9_4
  • libperf RHEL 9 5.14.0-427.13.1.el9_4
  • kernel-rt RHEL 9 5.14.0-427.13.1.el9_4
  • kernel-64k RHEL 9 5.14.0-427.13.1.el9_4

red hat advisories RHSA-2024:2394

  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-40.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-40.1
  • kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1
  • kernel-default Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1
  • kernel-kvmsmall Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1
  • kernel-default-base Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1.21.16
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.28.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.28.1

suse advisories SUSE-SU-2026:20845-1SUSE-SU-2026:20876-1SUSE-SU-2026:20477-1SUSE-SU-2026:20498-1SUSE-SU-2026:0473-1SUSE-SU-2026:0315-1

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-2023-53863 updated cvss 5.5

kernel: netlink: do not hard code device address lenth in fdb dumps

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: no fix planned “Out of support scope”
  • 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 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-427.13.1.el9_4, perf 5.14.0-427.13.1.el9_4, rtla 5.14.0-427.13.1.el9_4, kernel-devel-matched 5.14.0-427.13.1.el9_4, kernel-64k-devel-matched 5.14.0-427.13.1.el9_4, kernel-debug-devel-matched 5.14.0-427.13.1.el9_4, +6 more Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.3.0-427.13.1.el9_4, kernel 5.14.0-427.13.1.el9_4, kernel-64k 5.14.0-427.13.1.el9_4, kernel-core 5.14.0-427.13.1.el9_4, kernel-tools 5.14.0-427.13.1.el9_4, python3-perf 5.14.0-427.13.1.el9_4, +28 more Red Hat Enterprise Linux CRB (v. 9) libperf 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.13.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.13.1.el9_4 Red Hat Enterprise Linux NFV (v. 9) kernel-rt 5.14.0-427.13.1.el9_4, kernel-rt-kvm 5.14.0-427.13.1.el9_4, kernel-rt-core 5.14.0-427.13.1.el9_4, kernel-rt-modules 5.14.0-427.13.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.13.1.el9_4, kernel-rt-debug-core 5.14.0-427.13.1.el9_4, +6 more Red Hat Enterprise Linux RT (v. 9) kernel-rt 5.14.0-427.13.1.el9_4, kernel-rt-core 5.14.0-427.13.1.el9_4, kernel-rt-modules 5.14.0-427.13.1.el9_4, kernel-rt-debug-core 5.14.0-427.13.1.el9_4, kernel-rt-modules-core 5.14.0-427.13.1.el9_4, kernel-rt-debug-modules 5.14.0-427.13.1.el9_4, +4 more
    fixed: vendor fix RHSA-2024:2394
  • 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

0.26% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.