CVE-2022-49153

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

wireguard: socket: free skb in send6 when ipv6 is disabled

I got a memory leak report:

unreferenced object 0xffff8881191fc040 (size 232): comm kworker/u17:0, pid 23193, jiffies 4295238848 (age 3464.870s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ……………. 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ……………. backtrace: [] slab_post_alloc_hook+0x84/0x3b0 [] kmem_cache_alloc_node+0x167/0x340 [] __alloc_skb+0x1db/0x200 [] wg_socket_send_buffer_to_peer+0x3d/0xc0 [] wg_packet_send_handshake_initiation+0xfa/0x110 [] wg_packet_handshake_send_worker+0x21/0x30 [] process_one_work+0x2e8/0x770 [] worker_thread+0x4a/0x4b0 [] kthread+0x120/0x160 [] ret_from_fork+0x1f/0x30

In function wg_socket_send_buffer_as_reply_to_skb() or wg_socket_send_ buffer_to_peer(), the semantics of send6() is required to free skb. But when CONFIG_IPV6 is disable, kfree_skb() is missing. This patch adds it to fix this bug.

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/096f9d35cac0a0c95ffafc00db84786b665a4837
• https://git.kernel.org/stable/c/0b19bcb753dbfb74710d12bb2761ec5ed706c726
• https://git.kernel.org/stable/c/402991a9771587acc2947cf6c4d689c5397f2258
• https://git.kernel.org/stable/c/bbbf962d9460194993ee1943a793a0a0af4a7fbf
• https://git.kernel.org/stable/c/ebcc492f4ba14bae54b898f1016a37b4282558d1