Executive brief
A vulnerability in the Linux kernel's networking component could allow a remote attacker to cause a system crash or instability. The issue occurs when the system processes certain incoming network calls, leading to an internal error in how the kernel manages hardware interrupts. This could result in a denial-of-service, impacting the availability of affected servers and services.
Technical details
A vulnerability in the AF_RXRPC implementation in the Linux kernel arises from calling rxrpc_assess_MTU_size() while interrupts are disabled. This function calls into the IP layer, which utilizes local_bh_enable(), a routine that triggers a kernel warning or instability if invoked while hard interrupts are disabled. The issue is triggered during the processing of incoming calls in rxrpc_new_incoming_call(). An attacker can potentially trigger this condition via network traffic, leading to a denial-of-service (DoS). The fix involves moving the MTU assessment call to a point in the stack where interrupts have been re-enabled.
Affected products
- Linux Linux Kernel 6.14 to 6.15.8
Timeline
- 2025-07-17: patched: Initial fix committed to mainline kernel
- 2025-08-16: advisory: CVE-2025-38525 published