Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix deadlock between rcu_tasks_trace and event_mutex.
Fix the following deadlock: CPU A _free_event() perf_kprobe_destroy() mutex_lock(&event_mutex) perf_trace_event_unreg() synchronize_rcu_tasks_trace()
There are several paths where _free_event() grabs event_mutex and calls sync_rcu_tasks_trace. Above is one such case.
CPU B bpf_prog_test_run_syscall() rcu_read_lock_trace() bpf_prog_run_pin_on_cpu() bpf_prog_load() bpf_tracing_func_proto() trace_set_clr_event() mutex_lock(&event_mutex)
Delegate trace_set_clr_event() to workqueue to avoid such lock dependency.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 6 ELS , CloudLinux 7 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- kernel @ 2.6.32 (+16 more)
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix deadlock between rcu_tasks_trace and event_mutex.
Fix the following deadlock: CPU A _free_event() perf_kprobe_destroy() mutex_lock(&event_mutex) perf_trace_event_unreg() synchronize_rcu_tasks_trace()
There are several paths where _free_event() grabs event_mutex and calls sync_rcu_tasks_trace. Above is one such case.
CPU B bpf_prog_test_run_syscall() rcu_read_lock_trace() bpf_prog_run_pin_on_cpu() bpf_prog_load() bpf_tracing_func_proto() trace_set_clr_event() mutex_lock(&event_mutex)
Delegate trace_set_clr_event() to workqueue to avoid such lock dependency.