CVE-2024-50094: sfc: Don't invoke xdp_do_flush() from netpoll.

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-11-05 · updated 2026-08-04

Description

In the Linux kernel, the following vulnerability has been resolved: sfc: Don't invoke xdp_do_flush() from netpoll. Yury reported a crash in the sfc driver originated from netpoll_send_udp(). The netconsole sends a message and then netpoll invokes the driver's NAPI function with a budget of zero. It is dedicated to allow driver to free TX resources, that it may have used while sending the packet. In the netpoll case the driver invokes xdp_do_flush() unconditionally, leading to crash because bpf_net_context was never assigned. Invoke xdp_do_flush() only if budget is not zero.

Affected products

Linux kernel: from 6.11 before 6.11.4; 6.12-rc1, 6.12-rc2 — fixed in 6.11.4

How to fix

Upgrade to a fixed version: Linux kernel 6.11.4. Check the vendor advisory for mitigations.

References

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