CVE-2024-49977 net: stmmac: Fix zero-division error when disabling tc cbs
A zero-division error in the Linux kernel stmmac driver causes a denial of service when disabling traffic control CBS offload.
- 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-2024-49977?
CVE-2024-49977 is a medium-severity denial of service vulnerability in Linux kernel, published on 21 Oct 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:
net: stmmac: Fix zero-division error when disabling tc cbs
The commit b8c43360f6e4 ("net: stmmac: No need to calculate speed divider when offload is disabled") allows the "port_transmit_rate_kbps" to be set to a value of 0, which is then passed to the "div_s64" function when tc-cbs is disabled. This leads to a zero-division error.
When tc-cbs is disabled, the idleslope, sendslope, and credit values the credit values are not required to be configured. Therefore, adding a return statement after setting the txQ mode to DCB when tc-cbs is disabled would prevent a zero-division error.
Weakness: CWE-369
Which versions are affected by CVE-2024-49977?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-49977?
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-2024-49977 being exploited?
There is no known exploitation of CVE-2024-49977 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-51333, BELL-CVE-2024-49977, DEBIAN-CVE-2024-49977, GHSA-8cpm-hmp4-fcm6, UBUNTU-CVE-2024-49977.