CVE-2025-21629

Source
https://cve.org/CVERecord?id=CVE-2025-21629
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-21629.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2025-21629
Downstream
AZL (1)
BELL (1)
DEBIAN (1)
MGASA (2)
OESA (2)
ROOT (2)
SUSE (11)
UBUNTU (1)
Related
Published
2025-01-15T13:06:00Z
Modified
2026-10-20T11:05:40Z
Severity
  • 8.2 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H CVSS Calculator
Summary
net: reenable NETIF_F_IPV6_CSUM offload for BIG TCP packets
Details

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.

Database specific
{
    "cna_assigner":  "Linux",
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21629.json"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
a84978a9cda68f0afe3f01d476c68db21526baf1
Fixed
ac9cfef69565021c9e1022a493a9c40b03e2caf9
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
c69bc67c1cb211aa390bea6e512bb01b1241fefb
Fixed
95ccf006bbc8b59044313b8c309dcf29c546abd4
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
04c20a9356f283da623903e81e7c6d5df7e4dc3c
Fixed
d3b7a9c7597b779039a51d7b34116fbe424bf2b7
Fixed
68e068cabd2c6c533ef934c2e5151609cf6ecc6d
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
6.1.116
Fixed
6.1.124
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
6.6.60
Fixed
6.6.70
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
4.19.323
Fixed
4.20
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
5.4.285
Fixed
5.5
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
5.10.229
Fixed
5.11
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
5.15.171
Fixed
5.16
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
6.11.7
Fixed
6.12
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
bcefc3cd7f592a70fcbbbfd7ad1fbc69172ea78b
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
477b35d94a21530046fe91589960732fcf2b29ed
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
a27a5c40ee4cbe00294e2c76160de5f2589061ba
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
9f605135a5c0fe614c2b15197b9ced1e217eca59
Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
705350fbd6ed4b5d89ee045fa57a0594a72b17d7

Affected versions

v4.*
v4.19.323
v4.19.324
v4.19.325
v5.*
v5.10.229
v5.10.230
v5.10.231
v5.10.232
v5.10.233
v5.10.234
v5.10.235
v5.10.236
v5.10.237
v5.10.238
v5.10.239
v5.10.240
v5.10.241
v5.10.242
v5.10.243
v5.10.244
v5.10.245
v5.10.246
v5.10.247
v5.10.248
v5.10.249
v5.10.250
v5.10.251
v5.10.252
v5.10.253
v5.10.254
v5.10.255
v5.10.256
v5.10.257
v5.10.258
v5.10.259
v5.10.260
v5.10.261
v5.10.262
v5.10.263
v5.10.264
v5.10.265
v5.10.266
v5.10.267
v5.10.268
v5.10.269
v5.10.270
v5.10.271
v5.10.272
v5.15.171
v5.15.172
v5.15.173
v5.15.174
v5.15.175
v5.15.176
v5.15.177
v5.15.178
v5.15.179
v5.15.180
v5.15.181
v5.15.182
v5.15.183
v5.15.184
v5.15.185
v5.15.186
v5.15.187
v5.15.188
v5.15.189
v5.15.190
v5.15.191
v5.15.192
v5.15.193
v5.15.194
v5.15.195
v5.15.196
v5.15.197
v5.15.198
v5.15.199
v5.15.200
v5.15.201
v5.15.202
v5.15.203
v5.15.204
v5.15.205
v5.15.206
v5.15.207
v5.15.208
v5.15.209
v5.15.210
v5.15.211
v5.15.212
v5.15.213
v5.15.214
v5.15.215
v5.15.216
v5.15.217
v5.15.218
v5.15.219
v5.15.220
v5.15.221
v5.15.222
v5.15.223
v5.4.285
v5.4.286
v5.4.287
v5.4.288
v5.4.289
v5.4.290
v5.4.291
v5.4.292
v5.4.293
v5.4.294
v5.4.295
v5.4.296
v5.4.297
v5.4.298
v5.4.299
v5.4.300
v5.4.301
v5.4.302
v6.*
v6.1.116
v6.1.117
v6.1.118
v6.1.119
v6.1.120
v6.1.121
v6.1.122
v6.1.123
v6.11.10
v6.11.11
v6.11.7
v6.11.8
v6.11.9
v6.6.60
v6.6.61
v6.6.62
v6.6.63
v6.6.64
v6.6.65
v6.6.66
v6.6.67
v6.6.68
v6.6.69

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-21629.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
6.1.124
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.70
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.12.9

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-21629.json"