CVE-2025-68320 lan966x: Fix sleeping in atomic context
A bug in the lan966x network driver causes a kernel warning and potential instability when reading stats, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-68320?
CVE-2025-68320 is a high-severity denial of service vulnerability in Linux, published on 16 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
lan966x: Fix sleeping in atomic context
The following warning was seen when we try to connect using ssh to the device.
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:575 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 104, name: dropbear preempt_count: 1, expected: 0 INFO: lockdep is turned off. CPU: 0 UID: 0 PID: 104 Comm: dropbear Tainted: G W 6.18.0-rc2-00399-g6f1ab1b109b9-dirty #530 NONE Tainted: [W]=WARN Hardware name: Generic DT based system Call trace: unwind_backtrace from show_stack+0x10/0x14 show_stack from dump_stack_lvl+0x7c/0xac dump_stack_lvl from __might_resched+0x16c/0x2b0 __might_resched from __mutex_lock+0x64/0xd34 __mutex_lock from mutex_lock_nested+0x1c/0x24 mutex_lock_nested from lan966x_stats_get+0x5c/0x558 lan966x_stats_get from dev_get_stats+0x40/0x43c dev_get_stats from dev_seq_printf_stats+0x3c/0x184 dev_seq_printf_stats from dev_seq_show+0x10/0x30 dev_seq_show from seq_read_iter+0x350/0x4ec seq_read_iter from seq_read+0xfc/0x194 seq_read from proc_reg_read+0xac/0x100 proc_reg_read from vfs_read+0xb0/0x2b0 vfs_read from ksys_read+0x6c/0xec ksys_read from ret_fast_syscall+0x0/0x1c Exception stack(0xf0b11fa8 to 0xf0b11ff0) 1fa0: 00000001 00001000 00000008 be9048d8 00001000 00000001 1fc0: 00000001 00001000 00000008 00000003 be905920 0000001e 00000000 00000001 1fe0: 0005404c be9048c0 00018684 b6ec2cd8
It seems that we are using a mutex in a atomic context which is wrong. Change the mutex with a spinlock.
Which versions are affected by CVE-2025-68320?
How do I fix CVE-2025-68320?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-68320 being exploited?
There is no known exploitation of CVE-2025-68320 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-68320, DEBIAN-CVE-2025-68320, GHSA-f4gj-826g-pqfv, ROOT-OS-DEBIAN-12-CVE-2025-68320, ROOT-OS-DEBIAN-13-CVE-2025-68320, ROOT-OS-UBUNTU-2404-CVE-2025-68320 and 1 more.