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.
Metrics
Affected Vendors & Products
References
History
Wed, 15 Jan 2025 13:15:00 +0000
Type | Values Removed | Values Added |
---|---|---|
Description | 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. | |
Title | net: reenable NETIF_F_IPV6_CSUM offload for BIG TCP packets | |
References |
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MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2025-01-15T13:06:00.128Z
Updated: 2025-01-15T13:06:00.128Z
Reserved: 2024-12-29T08:45:45.725Z
Link: CVE-2025-21629
Vulnrichment
No data.
NVD
Status : Received
Published: 2025-01-15T13:15:15.220
Modified: 2025-01-15T13:15:15.220
Link: CVE-2025-21629
Redhat
No data.