CVE-2024-41088 can: mcp251xfd: fix infinite loop when xmit fails
A flaw in the Linux kernel MCP251XFD CAN driver causes an infinite loop during transmission failures, leading to a 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-2024-41088?
CVE-2024-41088 is a medium-severity denial of service vulnerability in Linux kernel, published on 29 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:
can: mcp251xfd: fix infinite loop when xmit fails
When the mcp251xfd_start_xmit() function fails, the driver stops processing messages, and the interrupt routine does not return, running indefinitely even after killing the running application.
Error messages: [ 441.298819] mcp251xfd spi2.0 can0: ERROR in mcp251xfd_start_xmit: -16 [ 441.306498] mcp251xfd spi2.0 can0: Transmit Event FIFO buffer not empty. (seq=0x000017c7, tef_tail=0x000017cf, tef_head=0x000017d0, tx_head=0x000017d3). ... and repeat forever.
The issue can be triggered when multiple devices share the same SPI interface. And there is concurrent access to the bus.
The problem occurs because tx_ring->head increments even if mcp251xfd_start_xmit() fails. Consequently, the driver skips one TX package while still expecting a response in mcp251xfd_handle_tefif_one().
Resolve the issue by starting a workqueue to write the tx obj synchronously if err = -EBUSY. In case of another error, decrement tx_ring->head, remove skb from the echo stack, and drop the message.
[mkl: use more imperative wording in patch description]
Weakness: CWE-835
Which versions are affected by CVE-2024-41088?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-41088?
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-2024-41088 being exploited?
There is no known exploitation of CVE-2024-41088 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-47983, BELL-CVE-2024-41088, DEBIAN-CVE-2024-41088, GHSA-jh57-6wf8-c6gg, ROOT-OS-DEBIAN-11-CVE-2024-41088, ROOT-OS-UBUNTU-2204-CVE-2024-41088 and 1 more.