CVE-2024-43889 padata: Fix possible divide-by-0 panic in padata_mt_helper()
A divide-by-zero error in the Linux kernel padata module can cause a system panic, leading to denial of service.
- 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
What is CVE-2024-43889?
CVE-2024-43889 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 Aug 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:
padata: Fix possible divide-by-0 panic in padata_mt_helper()
We are hit with a not easily reproducible divide-by-0 panic in padata.c at bootup time.
[ 10.017908] Oops: divide error: 0000 1 PREEMPT SMP NOPTI [ 10.017908] CPU: 26 PID: 2627 Comm: kworker/u1666:1 Not tainted 6.10.0-15.el10.x86_64 #1 [ 10.017908] Hardware name: Lenovo ThinkSystem SR950 [7X12CTO1WW]/[7X12CTO1WW], BIOS [PSE140J-2.30] 07/20/2021 [ 10.017908] Workqueue: events_unbound padata_mt_helper [ 10.017908] RIP: 0010:padata_mt_helper+0x39/0xb0 : [ 10.017963] Call Trace: [ 10.017968] <TASK> [ 10.018004] ? padata_mt_helper+0x39/0xb0 [ 10.018084] process_one_work+0x174/0x330 [ 10.018093] worker_thread+0x266/0x3a0 [ 10.018111] kthread+0xcf/0x100 [ 10.018124] ret_from_fork+0x31/0x50 [ 10.018138] ret_from_fork_asm+0x1a/0x30 [ 10.018147] </TASK>
Looking at the padata_mt_helper() function, the only way a divide-by-0 panic can happen is when ps->chunk_size is 0. The way that chunk_size is initialized in padata_do_multithreaded(), chunk_size can be 0 when the min_chunk in the passed-in padata_mt_job structure is 0.
Fix this divide-by-0 panic by making sure that chunk_size will be at least 1 no matter what the input parameters are.
Weakness: CWE-369
Which versions are affected by CVE-2024-43889?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-43889?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-43889 being exploited?
There is no known exploitation of CVE-2024-43889 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-48293, BELL-CVE-2024-43889, DEBIAN-CVE-2024-43889, GHSA-gq64-pw9q-3fw2, UBUNTU-CVE-2024-43889.