CVE-2025-21629

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.

• https://git.kernel.org/stable/c/68e068cabd2c6c533ef934c2e5151609cf6ecc6dPatch
• https://git.kernel.org/stable/c/95ccf006bbc8b59044313b8c309dcf29c546abd4Patch
• https://git.kernel.org/stable/c/ac9cfef69565021c9e1022a493a9c40b03e2caf9Patch
• https://git.kernel.org/stable/c/d3b7a9c7597b779039a51d7b34116fbe424bf2b7Patch
• https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html

Published

Jan 15, 2025

Last Modified

Jul 30, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2025-21622ClipBucket V5 provides open source video hosting with PHP. D…9.1
• CVE-2025-21623ClipBucket V5 provides open source video hosting with PHP. P…7.5
• CVE-2025-21624ClipBucket V5 provides open source video hosting with PHP. P…9.8
• CVE-2025-21626GLPI is a free asset and IT management software package. Sta…6.5
• CVE-2025-21627GLPI is a free asset and IT management software package. In …6.1
• CVE-2025-21628Chatwoot is a customer engagement suite. Prior to 3.16.0, co…8.8
• CVE-2025-2163The Zoorum Comments plugin for WordPress is vulnerable to Cr…5.4
• CVE-2025-21630Rejected reason: This CVE ID has been rejected or withdrawn …
• CVE-2025-21631In the Linux kernel, the following vulnerability has been re…7.8
• CVE-2025-21632In the Linux kernel, the following vulnerability has been re…5.5
• CVE-2025-21633Rejected reason: This CVE ID has been rejected or withdrawn …
• CVE-2025-21634In the Linux kernel, the following vulnerability has been re…5.5