CVE-2026-43036
MEDIUMnet: use skb_header_pointer() for TCPv4 GSO frag_off check
Title source: cnaDescription
In the Linux kernel, the following vulnerability has been resolved: net: use skb_header_pointer() for TCPv4 GSO frag_off check Syzbot reported a KMSAN uninit-value warning in gso_features_check() called from netif_skb_features() [1]. gso_features_check() reads iph->frag_off to decide whether to clear mangleid_features. Accessing the IPv4 header via ip_hdr()/inner_ip_hdr() can rely on skb header offsets that are not always safe for direct dereference on packets injected from PF_PACKET paths. Use skb_header_pointer() for the TCPv4 frag_off check so the header read is robust whether data is already linear or needs copying. [1] https://syzkaller.appspot.com/bug?extid=1543a7d954d9c6d00407
References (4)
Core 4
Core References
Scores
CVSS v3
5.5
EPSS
0.0001
EPSS Percentile
2.2%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Details
CWE
CWE-908
Status
published
Products (12)
Linux/Linux
< 4.7
Linux/Linux
4.7
Linux/Linux
6.12.81 - 6.12.*
Linux/Linux
6.18.22 - 6.18.*
Linux/Linux
6.19.12 - 6.19.*
Linux/Linux
7.0
Linux/Linux
cbc53e08a793b073e79f42ca33f1f3568703540d - cc91202fc20a44aab4c206f12a2bfe05da936051
Linux/Linux
cbc53e08a793b073e79f42ca33f1f3568703540d - d970341cfa5594614c7a6634886c7688b4f5cafd
Linux/Linux
cbc53e08a793b073e79f42ca33f1f3568703540d - ddc748a391dd8642ba6b2e4fe22e7f2ddf84b7f0
Linux/Linux
cbc53e08a793b073e79f42ca33f1f3568703540d - f7a6cd508e9e825a2c69fa9e13d41ee156852f25
... and 2 more
Published
May 01, 2026
Tracked Since
May 01, 2026