CVE-2025-40337: net: stmmac: Correctly handle Rx checksum offload errors
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: Correctly handle Rx checksum offload errors
The stmmacrx function would previously set skb->ipsummed to CHECKSUMUNNECESSARY if hardware checksum offload (CoE) was enabled and the packet was of a known IP ethertype.
However, this logic failed to check if the hardware had actually reported a checksum error. The hardware status, indicating a header or payload checksum failure, was being ignored at this stage. This could cause corrupt packets to be passed up the network stack as valid.
This patch corrects the logic by checking the csumnone status flag, which is set when the hardware reports a checksum error. If this flag is set, skb->ipsummed is now correctly set to CHECKSUMNONE, ensuring the kernel's network stack will perform its own validation and properly handle the corrupt packet.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2025-40337?
CVE-2025-40337 has been classified as a medium severity vulnerability.
How do I fix CVE-2025-40337?
To fix CVE-2025-40337, update your Linux kernel to the latest stable version that includes the patch for this vulnerability.
What components are affected by CVE-2025-40337?
CVE-2025-40337 affects the stmmac driver in the Linux kernel, particularly related to hardware checksum offload.
What issues does CVE-2025-40337 cause?
CVE-2025-40337 can lead to improper handling of received checksum errors, potentially affecting network communications.
Is CVE-2025-40337 exploitable?
Yes, CVE-2025-40337 is considered exploitable under certain conditions where hardware checksum offload is enabled.