# CVE-2024-40942: wifi: mac80211: mesh: Fix leak of mesh_preq_queue objects > A memory leak in the Linux kernel's mac80211 mesh networking code allows attackers to exhaust system memory, causing a denial of service. - **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`) - **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:** 12 Jul 2024 - **Updated:** 15 Oct 2026 - **Also known as:** BELL-CVE-2024-40942, DEBIAN-CVE-2024-40942, GHSA-jj67-2389-vrqj, UBUNTU-CVE-2024-40942 ## What is CVE-2024-40942? CVE-2024-40942 is a medium-severity denial of service vulnerability in Linux kernel, published on 12 Jul 2024. 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: wifi: mac80211: mesh: Fix leak of mesh_preq_queue objects The hwmp code use objects of type mesh_preq_queue, added to a list in ieee80211_if_mesh, to keep track of mpath we need to resolve. If the mpath gets deleted, ex mesh interface is removed, the entries in that list will never get cleaned. Fix this by flushing all corresponding items of the preq_queue in mesh_path_flush_pending(). This should take care of KASAN reports like this: unreferenced object 0xffff00000668d800 (size 128): comm "kworker/u8:4", pid 67, jiffies 4295419552 (age 1836.444s) hex dump (first 32 bytes): 00 1f 05 09 00 00 ff ff 00 d5 68 06 00 00 ff ff ..........h..... 8e 97 ea eb 3e b8 01 00 00 00 00 00 00 00 00 00 ....>........... backtrace: [<000000007302a0b6>] __kmem_cache_alloc_node+0x1e0/0x35c [<00000000049bd418>] kmalloc_trace+0x34/0x80 [<0000000000d792bb>] mesh_queue_preq+0x44/0x2a8 [<00000000c99c3696>] mesh_nexthop_resolve+0x198/0x19c [<00000000926bf598>] ieee80211_xmit+0x1d0/0x1f4 [<00000000fc8c2284>] __ieee80211_subif_start_xmit+0x30c/0x764 [<000000005926ee38>] ieee80211_subif_start_xmit+0x9c/0x7a4 [<000000004c86e916>] dev_hard_start_xmit+0x174/0x440 [<0000000023495647>] __dev_queue_xmit+0xe24/0x111c [<00000000cfe9ca78>] batadv_send_skb_packet+0x180/0x1e4 [<000000007bacc5d5>] batadv_v_elp_periodic_work+0x2f4/0x508 [<00000000adc3cd94>] process_one_work+0x4b8/0xa1c [<00000000b36425d1>] worker_thread+0x9c/0x634 [<0000000005852dd5>] kthread+0x1bc/0x1c4 [<000000005fccd770>] ret_from_fork+0x10/0x20 unreferenced object 0xffff000009051f00 (size 128): comm "kworker/u8:4", pid 67, jiffies 4295419553 (age 1836.440s) hex dump (first 32 bytes): 90 d6 92 0d 00 00 ff ff 00 d8 68 06 00 00 ff ff ..........h..... 36 27 92 e4 02 e0 01 00 00 58 79 06 00 00 ff ff 6'.......Xy..... backtrace: [<000000007302a0b6>] __kmem_cache_alloc_node+0x1e0/0x35c [<00000000049bd418>] kmalloc_trace+0x34/0x80 [<0000000000d792bb>] mesh_queue_preq+0x44/0x2a8 [<00000000c99c3696>] mesh_nexthop_resolve+0x198/0x19c [<00000000926bf598>] ieee80211_xmit+0x1d0/0x1f4 [<00000000fc8c2284>] __ieee80211_subif_start_xmit+0x30c/0x764 [<000000005926ee38>] ieee80211_subif_start_xmit+0x9c/0x7a4 [<000000004c86e916>] dev_hard_start_xmit+0x174/0x440 [<0000000023495647>] __dev_queue_xmit+0xe24/0x111c [<00000000cfe9ca78>] batadv_send_skb_packet+0x180/0x1e4 [<000000007bacc5d5>] batadv_v_elp_periodic_work+0x2f4/0x508 [<00000000adc3cd94>] process_one_work+0x4b8/0xa1c [<00000000b36425d1>] worker_thread+0x9c/0x634 [<0000000005852dd5>] kthread+0x1bc/0x1c4 [<000000005fccd770>] ret_from_fork+0x10/0x20 Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime) ## Which versions are affected by CVE-2024-40942? It affects 1 product. Products: Linux kernel. ## How do I fix CVE-2024-40942? Apply the vendor's patch. ## Is CVE-2024-40942 being exploited? There is no known exploitation of CVE-2024-40942 in the wild and no public exploit code. ## Other vulnerabilities in Linux kernel - [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild) - [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild) - [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild) - [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild) - [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2024-40942 and fix it if it is affected. What it is: CVE-2024-40942 is a medium-severity denial of service vulnerability in Linux kernel, published on 12 Jul 2024. 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-2024-40942 in the wild and no public exploit code. Affected product: Linux kernel. 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-2024-40942/ (Markdown: https://insights.sbomify.com/CVE-2024-40942/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-40942 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-40942 - OSV: https://osv.dev/vulnerability/CVE-2024-40942 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-40942/ Summaries are generated and may contain mistakes; the official description above is the record.