CVE-2024-53119

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

virtio/vsock: Fix accept_queue memory leak

As the final stages of socket destruction may be delayed, it is possible that virtio_transport_recv_listen() will be called after the accept_queue has been flushed, but before the SOCK_DONE flag has been set. As a result, sockets enqueued after the flush would remain unremoved, leading to a memory leak.

vsock_release __vsock_release lock virtio_transport_release virtio_transport_close schedule_delayed_work(close_work) sk_shutdown = SHUTDOWN_MASK (!) flush accept_queue release virtio_transport_recv_pkt vsock_find_bound_socket lock if flag(SOCK_DONE) return virtio_transport_recv_listen child = vsock_create_connected (!) vsock_enqueue_accept(child) release close_work lock virtio_transport_do_close set_flag(SOCK_DONE) virtio_transport_remove_sock vsock_remove_sock vsock_remove_bound release

Introduce a sk_shutdown check to disallow vsock_enqueue_accept() during socket destruction.

unreferenced object 0xffff888109e3f800 (size 2040): comm kworker/5:2, pid 371, jiffies 4294940105 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ……………. 28 00 0b 40 00 00 00 00 00 00 00 00 00 00 00 00 (..@………… backtrace (crc 9e5f4e84): [] kmem_cache_alloc_noprof+0x2c1/0x360 [] sk_prot_alloc+0x30/0x120 [] sk_alloc+0x2c/0x4b0 [] __vsock_create.constprop.0+0x2a/0x310 [] virtio_transport_recv_pkt+0x4dc/0x9a0 [] vsock_loopback_work+0xfd/0x140 [] process_one_work+0x20c/0x570 [] worker_thread+0x1bf/0x3a0 [] kthread+0xdd/0x110 [] ret_from_fork+0x2d/0x50 [] ret_from_fork_asm+0x1a/0x30

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/2415345042245de7601dcc6eafdbe3a3dcc9e379
• https://git.kernel.org/stable/c/4310902c766e371359e6c6311056ae80b5beeac9
• https://git.kernel.org/stable/c/897617a413e0bf1c6380e3b34b2f28f450508549
• https://git.kernel.org/stable/c/946c7600fa2207cc8d3fbc86a518ec56f98a5813
• https://git.kernel.org/stable/c/d7b0ff5a866724c3ad21f2628c22a63336deec3f
• https://git.kernel.org/stable/c/e26fa236758e8baa61a82cfd9fd4388d2e8d6a4c