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.
CVSS
No CVSS.
References
Configurations
No configuration.
History
16 Aug 2025, 12:15
Type | Values Removed | Values Added |
---|---|---|
New CVE |
Information
Published : 2025-08-16 12:15
Updated : 2025-08-16 12:15
NVD link : CVE-2025-38525
Mitre link : CVE-2025-38525
CVE.ORG link : CVE-2025-38525
JSON object : View
Products Affected
No product.
CWE
No CWE.