CVE-2022-50504 powerpc/rtas: avoid scheduling in rtas_os_term()
A kernel panic occurs in the Linux kernel's powerpc RTAS module when handling busy status during OS termination, causing a denial of service.
- 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-2022-50504?
CVE-2022-50504 is a medium-severity denial of service vulnerability in Linux kernel, published on 4 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:
powerpc/rtas: avoid scheduling in rtas_os_term()
It's unsafe to use rtas_busy_delay() to handle a busy status from the ibm,os-term RTAS function in rtas_os_term():
Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b BUG: sleeping function called from invalid context at arch/powerpc/kernel/rtas.c:618 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 1, name: swapper/0 preempt_count: 2, expected: 0 CPU: 7 PID: 1 Comm: swapper/0 Tainted: G D 6.0.0-rc5-02182-gf8553a572277-dirty #9 Call Trace: [c000000007b8f000] [c000000001337110] dump_stack_lvl+0xb4/0x110 (unreliable) [c000000007b8f040] [c0000000002440e4] __might_resched+0x394/0x3c0 [c000000007b8f0e0] [c00000000004f680] rtas_busy_delay+0x120/0x1b0 [c000000007b8f100] [c000000000052d04] rtas_os_term+0xb8/0xf4 [c000000007b8f180] [c0000000001150fc] pseries_panic+0x50/0x68 [c000000007b8f1f0] [c000000000036354] ppc_panic_platform_handler+0x34/0x50 [c000000007b8f210] [c0000000002303c4] notifier_call_chain+0xd4/0x1c0 [c000000007b8f2b0] [c0000000002306cc] atomic_notifier_call_chain+0xac/0x1c0 [c000000007b8f2f0] [c0000000001d62b8] panic+0x228/0x4d0 [c000000007b8f390] [c0000000001e573c] do_exit+0x140c/0x1420 [c000000007b8f480] [c0000000001e586c] make_task_dead+0xdc/0x200
Use rtas_busy_delay_time() instead, which signals without side effects whether to attempt the ibm,os-term RTAS call again.
Which versions are affected by CVE-2022-50504?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50504?
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-2022-50504 being exploited?
There is no known exploitation of CVE-2022-50504 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50504, GHSA-89wp-46hf-77pq, UBUNTU-CVE-2022-50504.