# CVE-2023-54112: kcm: Fix memory leak in error path of kcm_sendmsg() > A local attacker can trigger a memory leak in the Linux kernel KCM module, leading to resource exhaustion and denial of service. - **Severity:** Not scored - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 24 Dec 2025 - **Updated:** 11 May 2026 - **Also known as:** BELL-CVE-2023-54112, DEBIAN-CVE-2023-54112, GHSA-2f8x-cwx7-q35r, UBUNTU-CVE-2023-54112 ## What is CVE-2023-54112? CVE-2023-54112 is a memory corruption vulnerability in Linux, published on 24 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description In the Linux kernel, the following vulnerability has been resolved: kcm: Fix memory leak in error path of kcm_sendmsg() syzbot reported a memory leak like below: BUG: memory leak unreferenced object 0xffff88810b088c00 (size 240): comm "syz-executor186", pid 5012, jiffies 4294943306 (age 13.680s) hex dump (first 32 bytes): 00 89 08 0b 81 88 ff ff 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: [] __alloc_skb+0x1ef/0x230 net/core/skbuff.c:634 [] alloc_skb include/linux/skbuff.h:1289 [inline] [] kcm_sendmsg+0x269/0x1050 net/kcm/kcmsock.c:815 [] sock_sendmsg_nosec net/socket.c:725 [inline] [] sock_sendmsg+0x56/0xb0 net/socket.c:748 [] ____sys_sendmsg+0x365/0x470 net/socket.c:2494 [] ___sys_sendmsg+0xc9/0x130 net/socket.c:2548 [] __sys_sendmsg+0xa6/0x120 net/socket.c:2577 [] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 [] entry_SYSCALL_64_after_hwframe+0x63/0xcd In kcm_sendmsg(), kcm_tx_msg(head)->last_skb is used as a cursor to append newly allocated skbs to 'head'. If some bytes are copied, an error occurred, and jumped to out_error label, 'last_skb' is left unmodified. A later kcm_sendmsg() will use an obsoleted 'last_skb' reference, corrupting the 'head' frag_list and causing the leak. This patch fixes this issue by properly updating the last allocated skb in 'last_skb'. ## Which versions are affected by CVE-2023-54112? ## How do I fix CVE-2023-54112? Apply the vendor's patch. ## Is CVE-2023-54112 being exploited? There is no known exploitation of CVE-2023-54112 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2023-54112 and fix it if it is affected. What it is: CVE-2023-54112 is a memory corruption vulnerability in Linux, published on 24 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2023-54112 in the wild and no public exploit code. Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2023-54112/ (Markdown: https://insights.sbomify.com/CVE-2023-54112/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2023-54112 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-54112 - OSV: https://osv.dev/vulnerability/CVE-2023-54112 --- From sbomify Insights: https://insights.sbomify.com/CVE-2023-54112/ Summaries are generated and may contain mistakes; the official description above is the record.