CVE Catalog

CVE-2025-38525

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.28%

21th percentile - higher than 21% of all known CVEs

Summary

In the Linux kernel, a vulnerability in the RxRPC subsystem causes a warning in local_bh_enable() when rxrpc_assess_MTU_size() is called with interrupts disabled. This occurs during incoming call acceptance, leading to potential system instability.

Risk Assessment

The vulnerability may trigger warnings and system instability during RxRPC connection handling, potentially leading to denial of service (DoS) or unpredictable kernel behavior.

Recommendation

Immediately update the Linux kernel to a version containing the fix that moves the rxrpc_assess_MTU_size() call out of the interrupt-disabled section.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

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+0x403/0xb60 kthread+0x2f7/0x310 ret_from_fork+0x2a/0x230 ret_from_fork_asm+0x1a/0x30 ... hardirqs last enabled at (23): _raw_spin_unlock_irq+0x24/0x50 hardirqs last disabled at (24): _raw_read_lock_irq+0x17/0x70 softirqs last enabled at (0): copy_process+0xc61/0x2730 softirqs last disabled at (25): rt_add_uncached_list+0x3c/0x90 Fix this by moving the call to rxrpc_assess_MTU_size() out of rxrpc_init_peer() and further up the stack where it can be done without interrupts disabled. It shouldn't be a problem for rxrpc_new_incoming_call() to do it after the locks are dropped as pmtud is going to be performed by the I/O thread - and we're in the I/O thread at this point.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS