CVE-2024-35853: Linux kernel · mlxsw: spectrum_acl_tcam: Fix memory leak during rehash
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 6.4 Medium · fixed in 5.4.0-1128.138~18.04.1 : update Linux kernel when convenient.
Data as of 12 Nov 2026, 19:04 UTC
- Patch
- Available – fixed in 5.4.0-1128.138~18.04.1, 5.4.0-1133.140~18.04.1, 5.4.0-1132.141~18.04.1 +73
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 17 May 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-6896-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6898-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6896-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6898-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6896-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6898-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6896-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-6896-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-6898-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-6917-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6919-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6927-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-ibmpkg:deb/ubuntu/linux-ibm?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: mlxsw: spectrum_acl_tcam: Fix memory leak during rehash The rehash delayed work migrates filters from one region to another. This is done by iterating over all chunks (all the filters with the same priority) in the region and in each chunk iterating over all the filters. If the migration fails, the code tries to migrate the filters back to the old region. However, the rollback itself can also fail in which case another migration will be erroneously performed. Besides the fact that this ping pong is not a very good idea, it also creates a problem. Each virtual chunk references two chunks: The currently used one ('vchunk->chunk') and a backup ('vchunk->chunk2'). During migration the first holds the chunk we want to migrate filters to and the second holds the chunk we are migrating filters from. The code currently assumes - but does not verify - that the backup chunk does not exist (NULL) if the currently used chunk does not reference the target region. This assumption breaks when we are trying to rollback a rollback, resulting in the backup chunk being overwritten and leaked [1]. Fix by not rolling back a failed rollback and add a warning to avoid future cases. [1] WARNING: CPU: 5 PID: 1063 at lib/parman.c:291 parman_destroy+0x17/0x20 Modules linked in: CPU: 5 PID: 1063 Comm: kworker/5:11 Tainted: G W 6.9.0-rc2-custom-00784-gc6a05c468a0b #14 Hardware name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019 Workqueue: mlxsw_core mlxsw_sp_acl_tcam_vregion_rehash_work RIP: 0010:parman_destroy+0x17/0x20 [...] Call Trace: <TASK> mlxsw_sp_acl_atcam_region_fini+0x19/0x60 mlxsw_sp_acl_tcam_region_destroy+0x49/0xf0 mlxsw_sp_acl_tcam_vregion_rehash_work+0x1f1/0x470 process_one_work+0x151/0x370 worker_thread+0x2cb/0x3e0 kthread+0xd0/0x100 ret_from_fork+0x34/0x50 ret_from_fork_asm+0x1a/0x30 </TASK>
References
- ubuntu.com/security/CVE-2024-35853 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-35853 (opens in a new tab)
- git.kernel.org/linus/8ca3f7a7b61393804c46f170743c3b839df13977 (opens in a new tab)
- git.kernel.org/stable/c/c6f3fa7f5a748bf6e5c4eb742686d6952f854e76 (opens in a new tab)
- git.kernel.org/stable/c/617e98ba4c50f4547c9eb0946b1cfc26937d70d1 (opens in a new tab)
- git.kernel.org/stable/c/413a01886c3958d4b8aac23a3bff3d430b92093e (opens in a new tab)
- git.kernel.org/stable/c/b822644fd90992ee362c5e0c8d2556efc8856c76 (opens in a new tab)
- git.kernel.org/stable/c/0ae8ff7b6d42e33943af462910bdcfa2ec0cb8cf (opens in a new tab)
- git.kernel.org/stable/c/b3fd51f684a0711504f82de510da109ae639722d (opens in a new tab)
- git.kernel.org/stable/c/8ca3f7a7b61393804c46f170743c3b839df13977 (opens in a new tab)
- ubuntu.com/security/notices/USN-6896-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6898-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6896-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6898-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6896-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6898-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6896-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-6896-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-6898-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-6917-1 (opens in a new tab)