| Description: | In the Linux kernel, the following vulnerability has been resolved:
serial/pmac_zilog: Remove flawed mitigation for rx irq flood The
mitigation was intended to stop the irq completely. That may be better
than a hard lock-up but it turns out that you get a crash anyway if
you're using pmac_zilog as a serial console: ttyPZ0: pmz: rx irq flood
! BUG: spinlock recursion on CPU#0, swapper/0 That's because the
pr_err() call in pmz_receive_chars() results in pmz_console_write()
attempting to lock a spinlock already locked in pmz_interrupt(). With
CONFIG_DEBUG_SPINLOCK=y, this produces a fatal BUG splat. The spinlock
in question is the one in struct uart_port. Even when it's not fatal,
the serial port rx function ceases to work. Also, the iteration limit
doesn't play nicely with QEMU, as can be seen in the bug report linked
below. A web search for other reports of the error message "pmz: rx
irq flood" didn't produce anything. So I don't think this code is
needed any more. Remove it.
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