In the Linux kernel, the following vulnerability has been resolved:
net: reenable NETIF_F_IPV6_CSUM offload for BIG TCP packets
The blamed commit disabled hardware offoad of IPv6 packets with extension headers on devices that advertise NETIF_F_IPV6_CSUM, based on the definition of that feature in skbuff.h:
* * - %NETIF_F_IPV6_CSUM * - Driver (device) is only able to checksum plain * TCP or UDP packets over IPv6. These are specifically * unencapsulated packets of the form IPv6|TCP or * IPv6|UDP where the Next Header field in the IPv6 * header is either TCP or UDP. IPv6 extension headers * are not supported with this feature. This feature * cannot be set in features for a device with * NETIF_F_HW_CSUM also set. This feature is being * DEPRECATED (see below).
The change causes skb_warn_bad_offload to fire for BIG TCP packets.
[ 496.310233] WARNING: CPU: 13 PID: 23472 at net/core/dev.c:3129 skb_warn_bad_offload+0xc4/0xe0
[ 496.310297] ? skb_warn_bad_offload+0xc4/0xe0 [ 496.310300] skb_checksum_help+0x129/0x1f0 [ 496.310303] skb_csum_hwoffload_help+0x150/0x1b0 [ 496.310306] validate_xmit_skb+0x159/0x270 [ 496.310309] validate_xmit_skb_list+0x41/0x70 [ 496.310312] sch_direct_xmit+0x5c/0x250 [ 496.310317] __qdisc_run+0x388/0x620
BIG TCP introduced an IPV6_TLV_JUMBO IPv6 extension header to communicate packet length, as this is an IPv6 jumbogram. But, the feature is only enabled on devices that support BIG TCP TSO. The header is only present for PF_PACKET taps like tcpdump, and not transmitted by physical devices.
For this specific case of extension headers that are not transmitted, return to the situation before the blamed commit and support hardware offload.
ipv6_has_hopopt_jumbo() tests not only whether this header is present, but also that it is the only extension header before a terminal (L4) header.
CVSS Details
- CVSS 3.1 Base Score: 8.2
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon_linux_2023 | — | Upgrade kernel-libbpf-staticUpgrade kernelUpgrade kernel-toolsUpgrade kernel-libbpfUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-develUpgrade kernel-modules-extraUpgrade bpftoolUpgrade python3-perf-debuginfoUpgrade kernel-tools-debuginfoUpgrade bpftool-debuginfoUpgrade kernel-libbpf-develUpgrade kernel-livepatch-6.1.124-134.200Upgrade kernel-debuginfoUpgrade python3-perfUpgrade kernel-tools-develUpgrade kernel-headersUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-modules-extra-commonUpgrade perf-debuginfoUpgrade perf | Mar 27, 2025 | Jan 15, 2025 |
| Debian | — | Upgrade linux-6.1Upgrade linux | Feb 10, 2025 | Jan 15, 2025 |
| Redhat_linux | — | No solution exists | Jul 9, 2025 | Jan 15, 2025 |
| Suse | — | Upgrade dtb-alteraUpgrade gfs2-kmp-64kbUpgrade kernel-source-rtUpgrade gfs2-kmp-rtUpgrade kernel-debug-vdsoUpgrade kselftests-kmp-64kbUpgrade kselftests-kmp-azureUpgrade ocfs2-kmp-64kbUpgrade dtb-renesasUpgrade dtb-socionextUpgrade reiserfs-kmp-defaultUpgrade kernel-rt_debug-vdsoUpgrade kernel-debugUpgrade kernel-rt_debugUpgrade kernel-debug-develUpgrade kernel-kvmsmall-develUpgrade dlm-kmp-defaultUpgrade reiserfs-kmp-64kbUpgrade dtb-hisiliconUpgrade gfs2-kmp-defaultUpgrade kernel-source-azureUpgrade dtb-amazonUpgrade kernel-docs-htmlUpgrade dtb-amdUpgrade kernel-obs-buildUpgrade kernel-rt-optionalUpgrade kernel-default-livepatch-develUpgrade kernel-rt_debug-develUpgrade kernel-default-baseUpgrade kernel-zfcpdumpUpgrade dtb-freescaleUpgrade dtb-lgUpgrade kernel-azure-vdsoUpgrade dtb-broadcomUpgrade kernel-default-develUpgrade kernel-kvmsmall-vdsoUpgrade kernel-azure-extraUpgrade dtb-amlogicUpgrade kernel-syms-rtUpgrade dtb-appleUpgrade kernel-azureUpgrade kernel-rt-vdsoUpgrade kernel-kvmsmallUpgrade kernel-rt-livepatch-develUpgrade kernel-default-livepatchUpgrade kernel-sourceUpgrade reiserfs-kmp-rtUpgrade cluster-md-kmp-azureUpgrade dtb-caviumUpgrade dlm-kmp-64kbUpgrade kernel-azure-optionalUpgrade dtb-marvellUpgrade kernel-source-vanillaUpgrade kernel-64kbUpgrade kernel-64kb-optionalUpgrade gfs2-kmp-azureUpgrade kernel-develUpgrade cluster-md-kmp-64kbUpgrade kselftests-kmp-rtUpgrade reiserfs-kmp-azureUpgrade dtb-allwinnerUpgrade kernel-rt-extraUpgrade ocfs2-kmp-azureUpgrade dtb-rockchipUpgrade dtb-qcomUpgrade kernel-devel-rtUpgrade cluster-md-kmp-defaultUpgrade kernel-defaultUpgrade ocfs2-kmp-defaultUpgrade kselftests-kmp-defaultUpgrade dtb-armUpgrade kernel-macrosUpgrade kernel-devel-azureUpgrade kernel-default-extraUpgrade kernel-azure-develUpgrade kernel-symsUpgrade kernel-rtUpgrade kernel-default-optionalUpgrade kernel-rt-develUpgrade kernel-default-vdsoUpgrade dtb-exynosUpgrade dtb-xilinxUpgrade kernel-syms-azureUpgrade dtb-nvidiaUpgrade dlm-kmp-rtUpgrade dtb-mediatekUpgrade dtb-apmUpgrade dlm-kmp-azureUpgrade cluster-md-kmp-rtUpgrade kernel-64kb-develUpgrade ocfs2-kmp-rtUpgrade kernel-obs-qaUpgrade kernel-docsUpgrade kernel-default-base-rebuildUpgrade kernel-64kb-extraUpgrade dtb-sprd | Jun 18, 2025 | Jan 15, 2025 |
| Ubuntu | — | Upgrade linux-image-lowlatency-64kUpgrade linux-image-6.11.0-1013-oracleUpgrade linux-image-gcp-64kUpgrade linux-image-6.11.0-1011-lowlatencyUpgrade linux-image-azure-fdeUpgrade linux-image-6.11.0-1017-oemUpgrade linux-image-6.11.0-1012-azure-fdeUpgrade linux-image-raspiUpgrade linux-image-realtime-hwe-24.04Upgrade linux-image-6.11.0-1011-gcpUpgrade linux-image-azureUpgrade linux-image-6.11.0-1011-gcp-64kUpgrade linux-image-generic-64k-hwe-24.04Upgrade linux-image-6.11.0-1012-azureUpgrade linux-image-6.11.0-1010-raspiUpgrade linux-image-6.11.0-1007-realtimeUpgrade linux-image-6.11.0-1011-awsUpgrade linux-image-genericUpgrade linux-image-6.11.0-21-genericUpgrade linux-image-awsUpgrade linux-image-oem-24.04Upgrade linux-image-virtualUpgrade linux-image-oracleUpgrade linux-image-lowlatency-64k-hwe-24.04Upgrade linux-image-realtimeUpgrade linux-image-gcpUpgrade linux-image-lowlatency-hwe-24.04Upgrade linux-image-6.11.0-21-generic-64kUpgrade linux-image-oem-24.04bUpgrade linux-image-generic-64kUpgrade linux-image-oracle-64kUpgrade linux-image-6.11.0-1011-lowlatency-64kUpgrade linux-image-6.11.0-1013-oracle-64kUpgrade linux-image-generic-hwe-24.04Upgrade linux-image-lowlatencyUpgrade linux-image-virtual-hwe-24.04Upgrade linux-image-oem-24.04a | Mar 28, 2025 | Jan 15, 2025 |
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub