CVE-2025-37905 firmware: arm_scmi: Balance device refcount when destroying devices
A memory leak in the Linux kernel SCMI driver allows attackers to cause denial of service by exhausting kernel memory through repeated device creation and destruction.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-37905?
CVE-2025-37905 is a medium-severity memory corruption vulnerability in Debian Debian Linux, published on 20 May 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
firmware: arm_scmi: Balance device refcount when destroying devices
Using device_find_child() to lookup the proper SCMI device to destroy causes an unbalance in device refcount, since device_find_child() calls an implicit get_device(): this, in turns, inhibits the call of the provided release methods upon devices destruction.
As a consequence, one of the structures that is not freed properly upon destruction is the internal struct device_private dev->p populated by the drivers subsystem core.
KMemleak detects this situation since loading/unloding some SCMI driver causes related devices to be created/destroyed without calling any device_release method.
unreferenced object 0xffff00000f583800 (size 512): comm "insmod", pid 227, jiffies 4294912190 hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... ff ff ff ff ff ff ff ff 60 36 1d 8a 00 80 ff ff ........`6...... backtrace (crc 114e2eed): kmemleak_alloc+0xbc/0xd8 __kmalloc_cache_noprof+0x2dc/0x398 device_add+0x954/0x12d0 device_register+0x28/0x40 __scmi_device_create.part.0+0x1bc/0x380 scmi_device_create+0x2d0/0x390 scmi_create_protocol_devices+0x74/0xf8 scmi_device_request_notifier+0x1f8/0x2a8 notifier_call_chain+0x110/0x3b0 blocking_notifier_call_chain+0x70/0xb0 scmi_driver_register+0x350/0x7f0 0xffff80000a3b3038 do_one_initcall+0x12c/0x730 do_init_module+0x1dc/0x640 load_module+0x4b20/0x5b70 init_module_from_file+0xec/0x158
$ ./scripts/faddr2line ./vmlinux device_add+0x954/0x12d0 device_add+0x954/0x12d0: kmalloc_noprof at include/linux/slab.h:901 (inlined by) kzalloc_noprof at include/linux/slab.h:1037 (inlined by) device_private_init at drivers/base/core.c:3510 (inlined by) device_add at drivers/base/core.c:3561
Balance device refcount by issuing a put_device() on devices found via device_find_child().
Weakness: CWE-401
Which versions are affected by CVE-2025-37905?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-37905?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-37905 being exploited?
There is no known exploitation of CVE-2025-37905 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as BELL-CVE-2025-37905, DEBIAN-CVE-2025-37905, GHSA-8fw5-h4j9-4g35, ROOT-OS-DEBIAN-12-CVE-2025-37905, ROOT-OS-UBUNTU-2204-CVE-2025-37905, ROOT-OS-UBUNTU-2404-CVE-2025-37905 and 1 more.