U.S. flag   An official website of the United States government
Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock (Dot gov) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

CVE-2026-68386 Detail

Description

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Reject unhashed UDP sockets on sockmap update UDP sockets get SOCK_RCU_FREE set when (auto-)bound. This means sk_is_refcounted(unbound) = true, while sk_is_refcounted(bound) = false. Because sockmap accepts unbound UDP sockets, a BPF program can increment a socket's refcount via lookup. If the socket is subsequently bound, the transition from unbound to bound causes bpf_sk_release() to skip the decrement of the refcount, causing a memory leak. unreferenced object 0xffff88810bc2eb40 (size 1984): comm "test_progs", pid 2451, jiffies 4295320596 hex dump (first 32 bytes): 7f 00 00 01 7f 00 00 01 d2 04 1b b7 04 d2 00 00 ................ 02 00 01 40 00 00 00 00 00 00 00 00 00 00 00 00 ...@............ backtrace (crc bdee079d): kmem_cache_alloc_noprof+0x557/0x660 sk_prot_alloc+0x69/0x240 sk_alloc+0x30/0x460 inet_create+0x2ce/0xf80 __sock_create+0x25b/0x5c0 __sys_socket+0x119/0x1d0 __x64_sys_socket+0x72/0xd0 do_syscall_64+0xa1/0x5f0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Instead of special-casing for refcounted sockets, reject unhashed UDP sockets during sockmap updates, as there is no benefit to supporting those. This effectively reverts the commit under Fixes, with two exceptions: 1. sock_map_sk_state_allowed() maintains a fall-through `return true`. 2. In the spirit of commit b8b8315e39ff ("bpf, sockmap: Remove unhash handler for BPF sockmap usage"), the proto::unhash BPF handler is not reintroduced. Historical note: this issue is related to commit 67312adc96b5 ("bpf: reject unhashed sockets in bpf_sk_assign").


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to [email protected].

URL Source(s) Tag(s)
kernel.org
kernel.org
kernel.org
kernel.org
kernel.org
kernel.org

Weakness Enumeration

CWE-ID CWE Name Source

Change History

3 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-68386
NVD Published Date:
08/10/2026
NVD Last Modified:
08/19/2026
Source:
kernel.org