CVE-2023-53520 Bluetooth: Fix hci_suspend_sync crash
A race condition in the Linux kernel Bluetooth subsystem can cause a system crash when unregistering a device during suspend.
- 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-2023-53520?
CVE-2023-53520 is a high-severity vulnerability in Linux kernel, published on 1 Oct 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:
Bluetooth: Fix hci_suspend_sync crash
If hci_unregister_dev() frees the hci_dev object but hci_suspend_notifier may still be accessing it, it can cause the program to crash. Here's the call trace: <4>[102152.653246] Call Trace: <4>[102152.653254] hci_suspend_sync+0x109/0x301 [bluetooth] <4>[102152.653259] hci_suspend_dev+0x78/0xcd [bluetooth] <4>[102152.653263] hci_suspend_notifier+0x42/0x7a [bluetooth] <4>[102152.653268] notifier_call_chain+0x43/0x6b <4>[102152.653271] __blocking_notifier_call_chain+0x48/0x69 <4>[102152.653273] __pm_notifier_call_chain+0x22/0x39 <4>[102152.653276] pm_suspend+0x287/0x57c <4>[102152.653278] state_store+0xae/0xe5 <4>[102152.653281] kernfs_fop_write+0x109/0x173 <4>[102152.653284] __vfs_write+0x16f/0x1a2 <4>[102152.653287] ? selinux_file_permission+0xca/0x16f <4>[102152.653289] ? security_file_permission+0x36/0x109 <4>[102152.653291] vfs_write+0x114/0x21d <4>[102152.653293] __x64_sys_write+0x7b/0xdb <4>[102152.653296] do_syscall_64+0x59/0x194 <4>[102152.653299] entry_SYSCALL_64_after_hwframe+0x5c/0xc1
This patch holds the reference count of the hci_dev object while processing it in hci_suspend_notifier to avoid potential crash caused by the race condition.
Weakness: CWE-362
Which versions are affected by CVE-2023-53520?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53520?
Apply the vendor's patch.
Is CVE-2023-53520 being exploited?
There is no known exploitation of CVE-2023-53520 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-75246, BELL-CVE-2023-53520, DEBIAN-CVE-2023-53520, GHSA-fxhr-ffpx-g953, ROOT-OS-DEBIAN-11-CVE-2023-53520, ROOT-OS-UBUNTU-2204-CVE-2023-53520 and 1 more.