From: Al Viro <viro@ZenIV.linux.org.uk>
To: Yizhuo Zhai <yzhai003@ucr.edu>
Cc: mingo@kernel.org, keescook@chromium.org,
akpm@linux-foundation.org, paulmck@linux.vnet.ibm.com,
linux-kernel@vger.kernel.org, Chengyu Song <csong@cs.ucr.edu>,
Zhiyun Qian <zhiyunq@cs.ucr.edu>
Subject: Re: [PATCH] kernel/exit.c: pointer sighand could be uninitialized
Date: Thu, 3 May 2018 06:06:50 +0100 [thread overview]
Message-ID: <20180503050650.GX30522@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CABvMjLTfuDqNEt4+1E6R47UFQOj7N1SAhb3KCwxjHsxm7itaog@mail.gmail.com>
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.
next prev parent reply other threads:[~2018-05-03 5:07 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CABvMjLTfuDqNEt4+1E6R47UFQOj7N1SAhb3KCwxjHsxm7itaog@mail.gmail.com>
2018-05-03 4:50 ` [PATCH] kernel/exit.c: pointer sighand could be uninitialized Kees Cook
2018-05-03 5:06 ` Al Viro [this message]
2018-05-03 6:44 ` Chengyu Song
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