CVE-2022-50771
Description
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().
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2022-50771
Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2022-50771.html
Vendor advisory: redhat — https://access.redhat.com/errata/RHSA-2023:6583
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| rhel | 9 | fixed | |
| sles | affected | | |
| debian | bookworm | fixed | 6.1.4-1 |
| debian | bullseye | fixed | 5.10.178-1 |
| debian | forky | fixed | 6.1.4-1 |
| debian | sid | fixed | 6.1.4-1 |
| debian | trixie | fixed | 6.1.4-1 |
References
Verify integrity in audit chain (admin only). AS-IS.