CVE-2024-35853

MEDIUM
Published May 17, 2024 Modified Apr 7, 2025 CWE-401

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>

Is your site exposed to CVE-2024-35853?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

6.4
MEDIUM
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H

Weakness Type (CWE)

CWE-401 CWE-401

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
debian debian_linux

References

Frequently Asked Questions

What is CVE-2024-35853? +
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> It has a CVSS v3.1 base score of 6.4 (MEDIUM).
How severe is CVE-2024-35853? +
CVE-2024-35853 has a CVSS v3.1 score of 6.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.
What products are affected by CVE-2024-35853? +
CVE-2024-35853 affects products from debian, linux, specifically: debian_linux, linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2024-35853? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

Don't wait for an exploit

Scan your website for vulnerabilities like CVE-2024-35853 — free, no signup required.