CVE-2024-38597

In the Linux kernel, the following vulnerability has been resolved:

eth: sungem: remove .ndo_poll_controller to avoid deadlocks

Erhard reports netpoll warnings from sungem:

netpoll_send_skb_on_dev(): eth0 enabled interrupts in poll (gem_start_xmit+0x0/0x398) WARNING: CPU: 1 PID: 1 at net/core/netpoll.c:370 netpoll_send_skb+0x1fc/0x20c

gem_poll_controller() disables interrupts, which may sleep. We cant sleep in netpoll, it has interrupts disabled completely. Strangely, gem_poll_controller() doesnt even poll the completions, and instead acts as if an interrupt has fired so it just schedules NAPI and exits. None of this has been necessary for years, since netpoll invokes NAPI directly.

Weakness

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

Affected Software

Extended Description

Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/25.html
• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/27.html

References

• https://git.kernel.org/stable/c/476adb3bbbd7886e8251d3b9ce2d3c3e680f35d6
• https://git.kernel.org/stable/c/5de5aeb98f9a000adb0db184e32765e4815d860b
• https://git.kernel.org/stable/c/6400d205fbbcbcf9b8510157e1f379c1d7e2e937
• https://git.kernel.org/stable/c/ac0a230f719b02432d8c7eba7615ebd691da86f4
• https://git.kernel.org/stable/c/e22b23f5888a065d084e87db1eec639c445e677f
• https://git.kernel.org/stable/c/faf94f1eb8a34b2c31b2042051ef36f63420ecce
• https://git.kernel.org/stable/c/fbeeb55dbb33d562149c57e794f06b7414e44289