In the Linux kernel, the following vulnerability has been resolved:
ARM: 9484/1: enable interrupts when unhandled user faults are triggered
PREEMPT_RT requires interrupts to be enabled when sending signals.
When do_DataAbort()/do_PrefetchAbort() triggers unhandled user faults,
that is `inf->fn()` return a non-zero value, and the interrupts are not
enabled within the hook function, force_sig_fault() will be called
with interrupts disabled.
This can be triggered by user programs executing the bkpt instruction,
with kernel config CONFIG_PERF_EVENTS=n.
Enable interrupts in do_DataAbort()/do_PrefetchAbort() when unhandled
user faults are triggered to fix the issue.
