Tracker / CVE-2026-31428
CVE-2026-31428
In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_log: fix uninitialized padding leak in NFULA_PAYLOAD __build_packet_message() manually constructs the NFULA_PAYLOAD netlink attribute using skb_put() and skb_copy_bits(), bypassing the standard nla_reserve()/nla_put() helpers. While nla_total_size(data_len) bytes are allocated (including NLA alignment padding), only data_len bytes of actual packet data are copied. The trailing nla_padlen(data_len) bytes (1-3 when data_len is not 4-byte aligned) are never initialized, leaking stale heap contents to userspace via the NFLOG netlink socket. Replace the manual attribute construction with nla_reserve(), which handles the tailroom check, header setup, and padding zeroing via __nla_reserve(). The subsequent skb_copy_bits() fills in the payload data on top of the properly initialized attribute.
Affected products and versions
| linux | linux_kernel |
|---|---|
| linux | linux_kernel · 2.6.24 → 5.10.253 |
| linux | linux_kernel · 5.11 → 5.15.203 |
| linux | linux_kernel · 5.16 → 6.1.168 |
| linux | linux_kernel · 6.13 → 6.18.21 |
| linux | linux_kernel · 6.19 → 6.19.11 |
| linux | linux_kernel · 6.2 → 6.6.131 |
| linux | linux_kernel · 6.7 → 6.12.80 |