CVE-2022-50771
What it is
In the Linux kernel, the following vulnerability has been resolved: rcu: Fix __this_cpu_read() lockdep warning in rcu_force_quiescent_state() Running rcutorture with non-zero fqs_duration module parameter in a kernel built with CONFIG_PREEMPTION=y results in the following splat: BUG: using __this_cpu_read() in preemptible [00000000] code: rcu_torture_fqs/398 caller is __this_cpu_preempt_check+0x13/0x20 CPU: 3 PID: 398 Comm: rcu_torture_fqs Not tainted 6.0.0-rc1-yoctodev-standard+ Call Trace: <TASK> dump_stack_lvl+0x5b/0x86 dump_stack+0x10/0x16 check_preemption_disabled+0xe5/0xf0 __this_cpu_preempt_check+0x13/0x20 rcu_force_quiescent_state.part.0+0x1c/0x170 rcu_force_quiescent_state+0x1e/0x30 rcu_torture_fqs+0xca/0x160 ? rcu_torture_boost+0x430/0x430 kthread+0x192/0x1d0 ? kthread_complete_and_exit+0x30/0x30 ret_from_fork+0x22/0x30 </TASK> The problem is that rcu_force_quiescent_state() uses __this_cpu_read() in preemptible code instead of the proper raw_cpu_read(). This commit therefore changes __this_cpu_read() to raw_cpu_read().
At a glance
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: not scored yet.
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Record status
- Deferred
Is it in your code?
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Read https://cve-list.com/agent/cve/CVE-2022-50771.md and follow it. Check whether this project is affected by CVE-2022-50771. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
References
- https://git.kernel.org/stable/c/3d92527a919edd1aa381bdd6c299dd75a8167396
- https://git.kernel.org/stable/c/5a52380b8193cf8be6c4a6b94b86ef64ed80c0dc
- https://git.kernel.org/stable/c/80a3e7ab477b3655615fc1627c88c248d4ad28d9
- https://git.kernel.org/stable/c/98a5b1265a36e9d843a51ddd6c9fa02da50d2c57
- https://git.kernel.org/stable/c/a74af9b937707b42c3fd041aae1ed4ce2f337307
- https://git.kernel.org/stable/c/ceb1c8c9b8aa9199da46a0f29d2d5f08d9b44c15