Improper Check for Unusual or Exceptional Conditions in Linux kernel - CVE-2026-98277

Vulnerability details

The vulnerability allows a local user to cause a denial of service in a network transmit queue.

The vulnerability exists due to improper handling of error conditions that leave deferred doorbell writes and completion requests unissued in the fbnic transmit path when the final packet of a transmit burst is dropped. A local user can trigger a transmit burst that ends with a dropped packet to cause a denial of service in a network transmit queue.

The final packet can be dropped because of skb_put_padto(), skb_cow_head(), or DMA mapping failure. Pending descriptors can remain invisible to the hardware indefinitely if no subsequent transmission occurs on the same queue. The issue was reproduced under QEMU with failure injection, but was not observed in real-world operation.

Affected software

How to mitigate CVE-2026-98277

External References

• https://git.kernel.org/stable/c/28fb764d670aa22dcbd2a02fd8fd87ae8d3563a9
• https://git.kernel.org/stable/c/490599ab23134962a6d18a024e84541d77bdb999
• https://git.kernel.org/stable/c/60ef74357a36ed2a102a75bb68d37aa7f305b94e

Related Security Bulletins

• Improper Check for Unusual or Exceptional Conditions in Linux kernel meta fbnic driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more