CVE-2025-22005

In the Linux kernel, the following vulnerability has been resolved:

ipv6: Fix memleak of nhc_pcpu_rth_output in fib_check_nh_v6_gw().

fib_check_nh_v6_gw() expects that fib6_nh_init() cleans up everything when it fails.

Commit 7dd73168e273 (ipv6: Always allocate pcpu memory in a fib6_nh) moved fib_nh_common_init() before alloc_percpu_gfp() within fib6_nh_init() but forgot to add cleanup for fib6_nh->nh_common.nhc_pcpu_rth_output in case it fails to allocate fib6_nh->rt6i_pcpu, resulting in memleak.

Lets call fib_nh_common_release() and clear nhc_pcpu_rth_output in the error path.

Note that we can remove the fib6_nh_release() call in nh_create_ipv6() later in net-next.git.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

• https://git.kernel.org/stable/c/119dcafe36795a15ae53351cbbd6177aaf94ffef
• https://git.kernel.org/stable/c/16267a5036173d0173377545b4b6021b081d0933
• https://git.kernel.org/stable/c/1bd12dfc058e1e68759d313d7727d68dbc1b8964
• https://git.kernel.org/stable/c/29d91820184d5cbc70f3246d4911d96eaeb930d6
• https://git.kernel.org/stable/c/596a883c4ce2d2e9c175f25b98fed3a1f33fea38
• https://git.kernel.org/stable/c/77c41cdbe6bce476e08d3251c0d501feaf10a9f3
• https://git.kernel.org/stable/c/9740890ee20e01f99ff1dde84c63dcf089fabb98
• https://git.kernel.org/stable/c/d3d5b4b5ae263c3225db363ba08b937e2e2b0380