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OpenAdvisories
High · 8.2 CVE-2023-53333 EUVD-2023-59928GHSA-r2m9-j67m-7grm

netfilter: conntrack: dccp: copy entire header to stack buffer, not just basic one

Published Sep 16, 2025 · Updated Aug 5, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.15 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.4 Package: linux-aws-5.8 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-fips Package: linux-aws-hwe Package: linux-azure Package: linux-azure-4.15 Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.15 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.4 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.2 Package: linux-azure-fips Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-4.15 Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.15 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.4 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.15 Package: linux-hwe-5.19 Package: linux-hwe-5.4 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-5.15 Package: linux-ibm-5.4 Package: linux-intel Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-intel-iotg Package: linux-intel-iotg-5.15 Package: linux-iot Package: linux-kvm Package: linux-lowlatency Package: linux-lowlatency-hwe-5.15 Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lts-xenial Package: linux-nvidia Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-tegra Package: linux-nvidia-tegra-5.15 Package: linux-nvidia-tegra-igx Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.15 Package: linux-oracle-5.3 Package: linux-oracle-5.4 Package: linux-oracle-5.8 Package: linux-oracle-6.5 Package: linux-raspi Package: linux-raspi-5.4 Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.15 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.5 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx-zynqmp Platform: Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

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

netfilter: conntrack: dccp: copy entire header to stack buffer, not just basic one

Eric Dumazet says:
nf_conntrack_dccp_packet() has an unique:

dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh);

And nothing more is 'pulled' from the packet, depending on the content.
dh->dccph_doff, and/or dh->dccph_x ...)
So dccp_ack_seq() is happily reading stuff past the _dh buffer.

BUG: KASAN: stack-out-of-bounds in nf_conntrack_dccp_packet+0x1134/0x11c0
Read of size 4 at addr ffff000128f66e0c by task syz-executor.2/29371
[..]

Fix this by increasing the stack buffer to also include room for
the extra sequence numbers and all the known dccp packet type headers,
then pull again after the initial validation of the basic header.

While at it, mark packets invalid that lack 48bit sequence bit but
where RFC says the type MUST use them.

Compile tested only.

v2: first skb_header_pointer() now needs to adjust the size to
only pull the generic header. (Eric)

Heads-up: I intend to remove dccp conntrack support later this year.

Affected products

VendorProductAffectedFixed
Linux Linux 2.6.26 5.4.251

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 linux 6.4.4-1 —
Debian 13 linux 6.4.4-1 —
Debian 12 linux 6.1.52-1 —
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield 5.15.0-1027.29 —
Ubuntu 24.04 LTS linux-intel +9 No fix yet —
Ubuntu 22.04 LTS linux 5.15.0-86.96 —
Ubuntu 22.04 LTS linux-aws 5.15.0-1047.52 —
Ubuntu 22.04 LTS linux-azure 5.15.0-1049.56 —
Ubuntu 22.04 LTS linux-azure-fde 5.15.0-1049.56.1 —
Ubuntu 22.04 LTS linux-gcp 5.15.0-1044.52 —
Ubuntu 22.04 LTS linux-gke +1 5.15.0-1044.49 —
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1030.35 —
Ubuntu 22.04 LTS linux-ibm +1 5.15.0-1040.43 —
Ubuntu 22.04 LTS linux-intel-iotg 5.15.0-1043.49 —
Ubuntu 22.04 LTS linux-lowlatency 5.15.0-86.95 —
Ubuntu 22.04 LTS linux-nvidia 5.15.0-1037.37 —
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1018.18 —
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1005.5 —
Ubuntu 22.04 LTS linux-oracle 5.15.0-1045.51 —
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 22.04 LTS linux-xilinx-zynqmp 5.15.0-1025.29 —
Ubuntu 20.04 LTS linux 5.4.0-166.183 —
Ubuntu 20.04 LTS linux-aws 5.4.0-1113.123 —
Ubuntu 20.04 LTS linux-aws-5.15 5.15.0-1047.52~20.04.1 —
Ubuntu 20.04 LTS linux-azure 5.4.0-1119.126 —
Ubuntu 20.04 LTS linux-azure-5.15 5.15.0-1049.56~20.04.1 —
Ubuntu 20.04 LTS linux-bluefield 5.4.0-1074.80 —
Ubuntu 20.04 LTS linux-gcp 5.4.0-1117.126 —
Ubuntu 20.04 LTS linux-gcp-5.15 5.15.0-1044.52~20.04.1 —
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Ubuntu 20.04 LTS linux-hwe-5.15 5.15.0-86.96~20.04.1 —
Ubuntu 20.04 LTS linux-ibm 5.4.0-1060.65 —
Ubuntu 20.04 LTS linux-ibm-5.15 5.15.0-1040.43~20.04.1 —
Ubuntu 20.04 LTS linux-intel-iotg-5.15 5.15.0-1043.49~20.04.1 —
Ubuntu 20.04 LTS linux-iot 5.4.0-1025.26 —
Ubuntu 20.04 LTS linux-kvm 5.4.0-1102.108 —
Ubuntu 20.04 LTS linux-lowlatency-hwe-5.15 5.15.0-86.95~20.04.1 —
Ubuntu 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1018.18~20.04.1 —
Ubuntu 20.04 LTS linux-oracle 5.4.0-1112.121 —
Ubuntu 20.04 LTS linux-oracle-5.15 5.15.0-1045.51~20.04.1 —
Ubuntu 20.04 LTS linux-raspi 5.4.0-1097.109 —
Ubuntu 20.04 LTS linux-riscv-5.15 5.15.0-1043.47~20.04.1 —
Ubuntu 20.04 LTS linux-xilinx-zynqmp 5.4.0-1033.37 —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Show 12 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1040.42 —
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1048.54 —
Ubuntu Pro FIPS 20.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS 18.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS 16.04 LTS linux-fips No fix yet —
Ubuntu Pro FIPS-updates 20.04 LTS linux-aws-fips 5.4.0-1113.123+fips1 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-azure-fips 5.4.0-1119.126+fips1 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-fips 5.4.0-1088.97 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-gcp-fips 5.4.0-1117.126+fips1 —
Ubuntu Pro FIPS-updates 18.04 LTS linux-aws-fips 4.15.0-2105.111 —
Ubuntu Pro FIPS-updates 18.04 LTS linux-azure-fips 4.15.0-2084.90 —
Ubuntu Pro FIPS-updates 18.04 LTS linux-fips 4.15.0-1121.132 —
Ubuntu Pro FIPS-updates 18.04 LTS linux-gcp-fips 4.15.0-2068.73 —
Ubuntu Pro FIPS-updates 16.04 LTS linux-fips 4.4.0-1099.106 —
Ubuntu Pro FIPS-preview 22.04 LTS linux-fips No fix yet —
Ubuntu Pro 18.04 LTS linux 4.15.0-223.235 —
Ubuntu Pro 18.04 LTS linux-aws 4.15.0-1166.179 —
Ubuntu Pro 18.04 LTS linux-aws-5.4 5.4.0-1113.123~18.04.1 —
Ubuntu Pro 18.04 LTS linux-azure-4.15 4.15.0-1175.190 —
Ubuntu Pro 18.04 LTS linux-azure-5.4 5.4.0-1119.126~18.04.2 —
Ubuntu Pro 18.04 LTS linux-gcp-4.15 4.15.0-1160.177 —
Ubuntu Pro 18.04 LTS linux-gcp-5.4 5.4.0-1117.126~18.04.1 —
Ubuntu Pro 18.04 LTS linux-hwe-5.4 5.4.0-166.183~18.04.2 —
Ubuntu Pro 18.04 LTS linux-ibm-5.4 5.4.0-1060.65~18.04.1 —
Ubuntu Pro 18.04 LTS linux-kvm 4.15.0-1150.155 —
Ubuntu Pro 18.04 LTS linux-oracle 4.15.0-1129.140 —
Ubuntu Pro 18.04 LTS linux-oracle-5.4 5.4.0-1112.121~18.04.4 —
Ubuntu Pro 18.04 LTS linux-raspi-5.4 5.4.0-1097.109~18.04.2 —
Ubuntu Pro 16.04 LTS linux 4.4.0-252.286 —
Ubuntu Pro 16.04 LTS linux-aws 4.4.0-1167.182 —
Ubuntu Pro 16.04 LTS linux-aws-hwe 4.15.0-1166.179~16.04.1 —
Ubuntu Pro 16.04 LTS linux-azure 4.15.0-1175.190~16.04.1 —
Ubuntu Pro 16.04 LTS linux-gcp 4.15.0-1160.177~16.04.1 —
Ubuntu Pro 16.04 LTS linux-hwe 4.15.0-223.235~16.04.1 —
Ubuntu Pro 16.04 LTS linux-kvm 4.4.0-1130.140 —
Ubuntu Pro 16.04 LTS linux-oracle 4.15.0-1129.140~16.04.1 —
Ubuntu Pro 14.04 LTS linux No fix yet —
Ubuntu Pro 14.04 LTS linux-aws 4.4.0-1129.135 —
Ubuntu Pro 14.04 LTS linux-azure 4.15.0-1175.190~14.04.1 —
Ubuntu Pro 14.04 LTS linux-lts-xenial 4.4.0-252.286~14.04.1 —
ReleasePackageFixed inAdvisory
RHEL 9 bpftool 7.2.0-362.8.1.el9_3 RHSA-2023:6583
RHEL 9 rv +64 5.14.0-362.8.1.el9_3 RHSA-2023:6583
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +6 6.4.0-150700.53.22.1 SUSE-SU-2025:4057-1
SLES 15 SP7 kernel-azure +2 6.4.0-150700.20.18.1 SUSE-SU-2025:4132-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.22.1.150700.17.15.1 SUSE-SU-2025:4057-1
SLES 15 SP6 kernel-64kb +6 6.4.0-150600.23.73.1 SUSE-SU-2025:03600-1
SLES 15 SP6 kernel-azure +2 6.4.0-150600.8.52.1 SUSE-SU-2025:03634-1
SLES 15 SP6 kernel-default-base 6.4.0-150600.23.73.1.150600.12.32.1 SUSE-SU-2025:03600-1
SLES 15 SP5 kernel-64kb +6 5.14.21-150500.55.124.1 SUSE-SU-2025:03615-1
SLES 15 SP5 kernel-default-base 5.14.21-150500.55.124.1.150500.6.59.1 SUSE-SU-2025:03615-1
SLES 15 SP4 kernel-64kb +6 5.14.21-150400.24.179.1 SUSE-SU-2025:03628-1
SLES 15 SP4 kernel-default-base 5.14.21-150400.24.179.1.150400.24.92.1 SUSE-SU-2025:03628-1
SLES 15 SP3 kernel-64kb +7 5.3.18-150300.59.221.1 SUSE-SU-2025:03626-1
SLES 15 SP3 kernel-default-base 5.3.18-150300.59.221.1.150300.18.132.1 SUSE-SU-2025:03626-1
Show 25 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES 12 SP5 kernel-syms +2 4.12.14-122.275.1 SUSE-SU-2025:03614-1
SLES for SAP 15 SP5 kernel-default-base 5.14.21-150500.55.124.1.150500.6.59.1 SUSE-SU-2025:03615-1
SLES for SAP 15 SP5 kernel-docs +4 5.14.21-150500.55.124.1 SUSE-SU-2025:03615-1
SLES for SAP 15 SP4 kernel-default-base 5.14.21-150400.24.179.1.150400.24.92.1 SUSE-SU-2025:03628-1
SLES for SAP 15 SP4 kernel-docs +4 5.14.21-150400.24.179.1 SUSE-SU-2025:03628-1
SLES for SAP 15 SP3 kernel-default-base 5.3.18-150300.59.221.1.150300.18.132.1 SUSE-SU-2025:03626-1
SLES for SAP 15 SP3 kernel-docs +5 5.3.18-150300.59.221.1 SUSE-SU-2025:03626-1
SLE Micro 6.1 kernel-default-base 6.4.0-35.1.21.12 SUSE-SU-2025:20861-1
SLE Micro 6.1 kernel-rt +1 6.4.0-37.1 SUSE-SU-2025:20898-1
SLE Micro 6.1 kernel-source +2 6.4.0-35.1 SUSE-SU-2025:20861-1
SLE Micro 6.0 kernel-default-base 6.4.0-35.1.21.12 SUSE-SU-2025:20851-1
SLE Micro 6.0 kernel-rt +1 6.4.0-37.1 SUSE-SU-2025:20870-1
SLE Micro 6.0 kernel-source +2 6.4.0-35.1 SUSE-SU-2025:20851-1
SLE Micro 5.5 kernel-default-base 5.14.21-150500.55.124.1.150500.6.59.1 SUSE-SU-2025:03615-1
SLE Micro 5.5 kernel-rt +1 5.14.21-150500.13.109.1 SUSE-SU-2025:3761-1
SLE Micro 5.5 kernel-source +1 5.14.21-150500.55.124.1 SUSE-SU-2025:03615-1
SLE Micro 5.4 kernel-default 5.14.21-150400.24.179.1 SUSE-SU-2025:03628-1
SLE Micro 5.4 kernel-default-base 5.14.21-150400.24.179.1.150400.24.92.1 SUSE-SU-2025:03628-1
SLE Micro 5.4 kernel-rt +1 5.14.21-150400.15.133.1 SUSE-SU-2025:3716-1
SLE Micro 5.3 kernel-default 5.14.21-150400.24.179.1 SUSE-SU-2025:03628-1
SLE Micro 5.3 kernel-default-base 5.14.21-150400.24.179.1.150400.24.92.1 SUSE-SU-2025:03628-1
SLE Micro 5.3 kernel-rt +1 5.14.21-150400.15.133.1 SUSE-SU-2025:3716-1
SLE Micro 5.2 kernel-default 5.3.18-150300.59.221.1 SUSE-SU-2025:03626-1
SLE Micro 5.2 kernel-default-base 5.3.18-150300.59.221.1.150300.18.132.1 SUSE-SU-2025:03626-1
SLE Micro 5.2 kernel-rt +1 5.3.18-150300.223.1 SUSE-SU-2025:03613-1
SLE Micro 5.1 kernel-default 5.3.18-150300.59.221.1 SUSE-SU-2025:03626-1
SLE Micro 5.1 kernel-default-base 5.3.18-150300.59.221.1.150300.18.132.1 SUSE-SU-2025:03626-1
SLE Micro 5.1 kernel-rt +1 5.3.18-150300.223.1 SUSE-SU-2025:03613-1
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.22.1 SUSE-SU-2025:4057-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7-RT_Update_6 1-150700.1.3.1 SUSE-SU-2025:4141-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_6 1-150700.15.3.1 SUSE-SU-2025:4057-1
SLE Live Patching 15 SP6 kernel-default 6.4.0-150600.23.73.1 SUSE-SU-2025:03600-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_16 1-150600.1.3.1 SUSE-SU-2025:3751-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_16 1-150600.13.3.1 SUSE-SU-2025:03600-1
SLE Live Patching 15 SP5 kernel-default 5.14.21-150500.55.124.1 SUSE-SU-2025:03615-1
SLE Live Patching 15 SP5 kernel-livepatch-SLE15-SP5_Update_31 1-150500.11.3.1 SUSE-SU-2025:03615-1
SLE Live Patching 15 SP4 kernel-default 5.14.21-150400.24.179.1 SUSE-SU-2025:03628-1
SLE Live Patching 15 SP4 kernel-livepatch-SLE15-SP4_Update_45 1-150400.9.3.1 SUSE-SU-2025:03628-1
SLE Live Patching 15 SP3 kernel-default 5.3.18-150300.59.221.1 SUSE-SU-2025:03626-1
SLE Live Patching 15 SP3 kernel-livepatch-SLE15-SP3_Update_62 1-150300.7.3.1 SUSE-SU-2025:03626-1
SLE Live Patching 12 SP5 kernel-default 4.12.14-122.275.1 SUSE-SU-2025:03614-1
SLE Live Patching 12 SP5 kgraft-patch-SLE12-SP5_Update_73 1-8.3.1 SUSE-SU-2025:03614-1
SLE HPC 15 SP5 kernel-64kb +5 5.14.21-150500.55.124.1 SUSE-SU-2025:03615-1
SLE HPC 15 SP5 kernel-default-base 5.14.21-150500.55.124.1.150500.6.59.1 SUSE-SU-2025:03615-1
SLE HPC 15 SP4 kernel-64kb +5 5.14.21-150400.24.179.1 SUSE-SU-2025:03628-1
SLE HPC 15 SP4 kernel-default-base 5.14.21-150400.24.179.1.150400.24.92.1 SUSE-SU-2025:03628-1
SLE HPC 15 SP3 kernel-64kb +6 5.3.18-150300.59.221.1 SUSE-SU-2025:03626-1
SLE HPC 15 SP3 kernel-default-base 5.3.18-150300.59.221.1.150300.18.132.1 SUSE-SU-2025:03626-1
SUSE Real Time Module 15 SP7 kernel-rt +2 6.4.0-150700.7.22.1 SUSE-SU-2025:4141-1
SUSE Real Time Module 15 SP6 kernel-rt +3 6.4.0-150600.10.55.1 SUSE-SU-2025:3751-1
SUSE Manager Server LTS 4.3 kernel-default-base 5.14.21-150400.24.179.1.150400.24.92.1 SUSE-SU-2025:03628-1
SUSE Manager Server LTS 4.3 kernel-syms +3 5.14.21-150400.24.179.1 SUSE-SU-2025:03628-1
SUSE Manager Proxy LTS 4.3 kernel-default-base 5.14.21-150400.24.179.1.150400.24.92.1 SUSE-SU-2025:03628-1
SUSE Manager Proxy LTS 4.3 kernel-syms +2 5.14.21-150400.24.179.1 SUSE-SU-2025:03628-1
SUSE Enterprise Storage 7.1 kernel-64kb +6 5.3.18-150300.59.221.1 SUSE-SU-2025:03626-1
SUSE Enterprise Storage 7.1 kernel-default-base 5.3.18-150300.59.221.1.150300.18.132.1 SUSE-SU-2025:03626-1
ReleasePackageFixed inAdvisory
openSUSE Leap 15.6 dtb-aarch64 +10 6.4.0-150600.23.73.1 SUSE-SU-2025:03600-1
openSUSE Leap 15.6 kernel-azure +2 6.4.0-150600.8.52.1 SUSE-SU-2025:03634-1
openSUSE Leap 15.6 kernel-default-base 6.4.0-150600.23.73.1.150600.12.32.1 SUSE-SU-2025:03600-1
openSUSE Leap 15.6 kernel-rt +3 6.4.0-150600.10.55.1 SUSE-SU-2025:3751-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 kernel-livepatch-6.1.41-63.109 1.0-0.amzn2023 ALAS2023-2023-299
Amazon Linux 2023 perf +12 6.1.41-63.109.amzn2023 ALAS2023-2023-299

Advisories 21

References