Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-06-25T00:00:00 kernel: netfilter: nft_fib: fix stale stack leak via the OIFNAME register 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-824

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_fib: fix stale stack leak via the OIFNAME register For NFT_FIB_RESULT_OIFNAME the destination register is declared with len = IFNAMSIZ (four 32-bit registers), but on the lookup-fail, RTN_LOCAL and oif-mismatch paths nft_fib{4,6}_eval() only writes one register via "*dest = 0". The remaining three registers are left as whatever was on the stack in nft_do_chain()'s struct nft_regs, and a downstream expression that loads the register span can leak that uninitialised kernel stack to userspace. The NFTA_FIB_F_PRESENT existence check has the same shape: it is only meaningful for NFT_FIB_RESULT_OIF, yet it was accepted for any result type while the eval stores a single byte via nft_reg_store8(), leaving the rest of the declared span stale. Fix both: - replace the bare "*dest = 0" in the eval with nft_fib_store_result(), which strscpy_pad()s the whole IFNAMSIZ for OIFNAME (and is already used on the other early-return path), and - restrict NFTA_FIB_F_PRESENT to NFT_FIB_RESULT_OIF and declare its destination as a single u8, so the marked span matches the one byte the eval writes.

A flaw was found in the Linux kernel's netfilter component. This vulnerability, a stale stack leak, occurs when certain network filtering operations do not properly clear memory. An attacker could potentially exploit this to access sensitive information from the kernel's memory, leading to information disclosure.

Red Hat Enterprise Linux 10 Fix deferred kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Fix deferred kernel Red Hat Enterprise Linux 8 Fix deferred kernel-rt Red Hat Enterprise Linux 9 Fix deferred kernel Red Hat Enterprise Linux 9 Fix deferred kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-53134 https://nvd.nist.gov/vuln/detail/CVE-2026-53134 https://lore.kernel.org/linux-cve-announce/2026062542-CVE-2026-53134-3dd1@gregkh/T