CVE-2025-38525

A flaw was found in the Linux kernel’s Remote Execution RPC (RxRPC) implementation, where the rxrpc_assess_MTU_size() function is invoked with interrupts disabled during the handling of an incoming call. This function queries the IP layer for route MTU information, but the IP layer internally uses local_bh_enable(), which can raise warnings if executed while IRQs are disabled. As a result, a race condition could occur, leading to kernel warnings and potential instability.

A flaw of Moderate security impact was found in the Linux kernel's RxRPC (Remote Execution RPC) implementation as shipped in Red Hat Enterprise Linux 10. When an incoming RxRPC call is accepted, the kernel calls rxrpc_assess_MTU_size() from rxrpc_new_incoming_call() with interrupts disabled in order to determine the route MTU size. The IP-layer routing code that it calls into uses local_bh_enable(), which, depending on kernel configuration, emits a warning when invoked while IRQs are disabled (for example, a WARNING at __local_bh_enable_ip() in kernel/softirq.c). The consequence is kernel warnings and potential system instability, affecting availability only; there is no impact on confidentiality or integrity. Of the Red Hat products, only the Red Hat Enterprise Linux 10 kernel is affected, and those affected streams are currently resolved as WONTFIX, so no fix is planned there; the residual risk is limited to kernel warnings and potential system instability with availability-only impact. Red Hat Enterprise Linux 6, 7, 8, and 9 (kernel and kernel-rt) and Red Hat In-Vehicle OS 1.0 and 1.1 are not affected because the vulnerable code is not present in those streams. The CVE.org record assigns this issue an Important rating using a network attack vector (CVSS 3.1 score 7.5, AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), whereas Red Hat rates it Moderate (CVSS 3.1 score 4.4, AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H), reflecting Red Hat's assessment of a local attack vector requiring high privileges with availability-only impact.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.