Re: [PATCH] kernel/exit.c: pointer sighand could be uninitialized

[Al Viro]

On Wed, May 02, 2018 at 06:48:57PM -0700, Yizhuo Zhai wrote:
> Variable 'sighand' could be uninitialized if probe_kernel_address fails
> (-EFAULT). The later use in the if statement may lead to undefined behavior.

Excuse me, but that's nonsense.  The value *copied* into it (in case
probe_kernel_address() has not failed) may be just as uninitialized.
If mere "compare uninitialized pointer value to NULL" can cause nasal demons to fly,
	* we are screwed anyway
	* the piece of crap compiler should be printed on sandpaper and used to
polish its authors.

Read the comments in there, please.  Especially the one regarding the second case.