Description
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
linux: linux kernel
References10
- git.kernel.org/stable/c/21d8efda029948d3666b0db5afcc0d36c0984aae Patch
- git.kernel.org/stable/c/52025ebaa29f4eb4ed8bf92ce83a68f24ab7fdf7 Patch
- git.kernel.org/stable/c/7eff72968161fb8ddb26113344de3b92fb7d7ef5 Patch
- git.kernel.org/stable/c/7f3e5d72455936f42709116fabeca3bb216cda62 Patch
- git.kernel.org/stable/c/a2f6ff3444b663d6cfa63eadd61327a18592885a Patch
- git.kernel.org/stable/c/a8365d1064ded323797c5e28e91070c52f44b76c Patch
- git.kernel.org/stable/c/c9f6c51d36482805ac3ffadb9663fe775a13e926 Patch
- git.kernel.org/stable/c/fc961dd7272b5e4a462999635e44a4770d7f2482 Patch
- cert-portal.siemens.com/productcert/html/ssa-019113.html
- cert-portal.siemens.com/productcert/html/ssa-082556.html
Metrics
- CVSS 3.1
-
5.5
MEDIUM
Score source: NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 0% percentile: 3 · as of 12 November 2026
- CWE
- CWE-908
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