NetSight
medium5.5

CVE-2026-43036

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-v…

Impact

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

Affected products

VendorProductAffected versions
LinuxLinux Kernel
from 4.7 before 6.12.81
from 6.13 before 6.18.22
from 6.19 before 6.19.12
Version 7.0

Weakness classification

References