serial: sc16is7xx: fix TX fifo corruption
CVE-2024-44951 · published 4 Sept 2024
How serious is it
- Severity: high, CVSS score 7.8 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2024-44951?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Linux Linux: 9879e1bec3c0f077427dd0d258c80c63ce9babdf to < 2a0ba376cdf729b5c66226c65c6c7cf9de744d52, 4409df5866b7ff7686ba27e449ca97a92ee063c9 to < 09cfe05e9907f3276887a20e267cc40e202f4fdd, 4409df5866b7ff7686ba27e449ca97a92ee063c9 to < 133f4c00b8b2bfcacead9b81e7e8edfceb4b06c4, 4b068e55bf5ea7bab4d8a282c6a24b03e80c0b68
- Linux Linux: 6.8
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
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.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- git.kernel.org/stable/c/2a0ba376cdf729b5c66226c65c6c7cf9de744d52
- git.kernel.org/stable/c/09cfe05e9907f3276887a20e267cc40e202f4fdd
- git.kernel.org/stable/c/133f4c00b8b2bfcacead9b81e7e8edfceb4b06c4
Merged from CVE List. Last updated 25 Oct 2026. All vulnerabilities · RSS · JSON