From: Leon Romanovsky <leon@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Colin Ian King <colin.king@canonical.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH rdma-next 1/4] gcov: Open-code kmemdup() to work correctly with kernel and user space pointers
Date: Wed, 2 Sep 2020 21:44:49 +0300 [thread overview]
Message-ID: <20200902184449.GN59010@unreal> (raw)
In-Reply-To: <CAHk-=whG7MPx0_6S8ATd4yRPtwKTThDNtbKQDQARHbaPp2H1Wg@mail.gmail.com>
On Wed, Sep 02, 2020 at 11:27:14AM -0700, Linus Torvalds wrote:
> On Wed, Sep 2, 2020 at 10:46 AM Leon Romanovsky <leon@kernel.org> wrote:
> >
> > Definitely my explanation is wrong, but it was my interpretation of
> > "BUG: KASAN: global-out-of-bounds in kmemdup+0x43/0x70" line. I saw
> > that the failure was in memcpy() inside of kmemdup(), so I changed
> > from memcpy to be copy_from_user() and it solved the KASAN warning.
>
> But the actual patch attached to that explanation *doesn't* use
> copy_from_user().
>
> So your "changed from memcpy to be copy_from_user() solved the KASAN
> warning" explanation makes even less sense. Because that's not at all
> what the patch does.
I already don't remember why, but copy_from_user() caused to second flow
of gcov_info_dup() through gcov_event() to generate another set of warnings.
As a summary, I have a workaround, but I don't know why it works and not
proud about it.
Thanks
>
> Linus
next prev parent reply other threads:[~2020-09-02 18:44 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-02 8:55 [PATCH -rc 0/4] Protect from GCC garbage input in GCOV Leon Romanovsky
2020-09-02 8:55 ` [PATCH rdma-next 1/4] gcov: Open-code kmemdup() to work correctly with kernel and user space pointers Leon Romanovsky
2020-09-02 17:38 ` Linus Torvalds
2020-09-02 17:46 ` Leon Romanovsky
2020-09-02 18:27 ` Linus Torvalds
2020-09-02 18:44 ` Leon Romanovsky [this message]
2020-09-02 19:04 ` Linus Torvalds
2020-09-02 8:55 ` [PATCH rdma-next 2/4] gcov: Use proper duplication routine for const pointer Leon Romanovsky
2020-09-03 8:56 ` Rasmus Villemoes
2020-09-03 10:38 ` Leon Romanovsky
2020-09-02 8:55 ` [PATCH rdma-next 3/4] gcov: Protect from uninitialized number of functions provided by GCC 10.2 Leon Romanovsky
2020-09-02 17:41 ` Linus Torvalds
2020-09-02 8:55 ` [PATCH rdma-next 4/4] gcov: Don't print out-of-memory print for all failed files Leon Romanovsky
2020-09-02 17:42 ` [PATCH -rc 0/4] Protect from GCC garbage input in GCOV Linus Torvalds
2020-09-02 17:52 ` Leon Romanovsky
2020-09-02 18:24 ` Linus Torvalds
2020-09-02 18:28 ` Leon Romanovsky
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