CVE-2024-44951 serial: sc16is7xx: fix TX fifo corruption
A race condition in the sc16is7xx serial driver allows received data to corrupt transmit buffers, potentially altering outgoing data.
- 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-2024-44951?
CVE-2024-44951 is a high-severity vulnerability in Linux kernel, published on 4 Sep 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:
serial: sc16is7xx: fix TX fifo corruption
Sometimes, when a packet is received on channel A at almost the same time as a packet is about to be transmitted on channel B, we observe with a logic analyzer that the received packet on channel A is transmitted on channel B. In other words, the Tx buffer data on channel B is corrupted with data from channel A.
The problem appeared since commit 4409df5866b7 ("serial: sc16is7xx: change EFR lock to operate on each channels"), which changed the EFR locking to operate on each channel instead of chip-wise.
This commit has introduced a regression, because the EFR lock is used not only to protect the EFR registers access, but also, in a very obscure and undocumented way, to protect access to the data buffer, which is shared by the Tx and Rx handlers, but also by each channel of the IC.
Fix this regression first by switching to kfifo_out_linear_ptr() in sc16is7xx_handle_tx() to eliminate the need for a shared Rx/Tx buffer.
Secondly, replace the chip-wise Rx buffer with a separate Rx buffer for each channel.
Weakness: CWE-667
Which versions are affected by CVE-2024-44951?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-44951?
Apply the vendor's patch.
Is CVE-2024-44951 being exploited?
There is no known exploitation of CVE-2024-44951 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-50225, BELL-CVE-2024-44951, DEBIAN-CVE-2024-44951, GHSA-qx5p-7g35-jj49, ROOT-OS-DEBIAN-12-CVE-2024-44951, ROOT-OS-UBUNTU-2404-CVE-2024-44951 and 1 more.