CVE-2025-38525

/// Technical description

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

rxrpc: Fix irq-disabled in local_bh_enable()

The rxrpc_assess_MTU_size() function calls down into the IP layer to find

out the MTU size for a route. When accepting an incoming call, this is

called from rxrpc_new_incoming_call() which holds interrupts disabled

across the code that calls down to it. Unfortunately, the IP layer uses

local_bh_enable() which, config dependent, throws a warning if IRQs are

enabled:

WARNING: CPU: 1 PID: 5544 at kernel/softirq.c:387 __local_bh_enable_ip+0x43/0xd0

...

RIP: 0010:__local_bh_enable_ip+0x43/0xd0

...

Call Trace:

<TASK>

rt_cache_route+0x7e/0xa0

rt_set_nexthop.isra.0+0x3b3/0x3f0

__mkroute_output+0x43a/0x460

ip_route_output_key_hash+0xf7/0x140

ip_route_output_flow+0x1b/0x90

rxrpc_assess_MTU_size.isra.0+0x2a0/0x590

rxrpc_new_incoming_peer+0x46/0x120

rxrpc_alloc_incoming_call+0x1b1/0x400

rxrpc_new_incoming_call+0x1da/0x5e0

rxrpc_input_packet+0x827/0x900

rxrpc_io_thread+0

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References