CVE-2022-50206 arm64: fix oops in concurrently setting insn_emulation sysctls
A race condition in the Linux kernel arm64 emulation sysctl handler causes a null pointer dereference, leading to a system crash.
- 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-2022-50206?
CVE-2022-50206 is a medium-severity vulnerability in Linux kernel, published on 18 Jun 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:
arm64: fix oops in concurrently setting insn_emulation sysctls
emulation_proc_handler() changes table->data for proc_dointvec_minmax and can generate the following Oops if called concurrently with itself:
| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 | Internal error: Oops: 96000006 [#1] SMP | Call trace: | update_insn_emulation_mode+0xc0/0x148 | emulation_proc_handler+0x64/0xb8 | proc_sys_call_handler+0x9c/0xf8 | proc_sys_write+0x18/0x20 | __vfs_write+0x20/0x48 | vfs_write+0xe4/0x1d0 | ksys_write+0x70/0xf8 | __arm64_sys_write+0x20/0x28 | el0_svc_common.constprop.0+0x7c/0x1c0 | el0_svc_handler+0x2c/0xa0 | el0_svc+0x8/0x200
To fix this issue, keep the table->data as &insn->current_mode and use container_of() to retrieve the insn pointer. Another mutex is used to protect against the current_mode update but not for retrieving insn_emulation as table->data is no longer changing.
Weakness: CWE-476
Which versions are affected by CVE-2022-50206?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50206?
Apply the vendor's patch.
Is CVE-2022-50206 being exploited?
There is no known exploitation of CVE-2022-50206 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50206, GHSA-qgp7-v6fq-jxvw, UBUNTU-CVE-2022-50206.