From: Omar Sandoval <osandov@osandov.com>
To: Dominique Martinet <asmadeus@codewreck.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Alexey Dobriyan <adobriyan@gmail.com>,
Eric Biederman <ebiederm@xmission.com>,
James Morse <james.morse@arm.com>,
Bhupesh Sharma <bhsharma@redhat.com>,
kernel-team@fb.com
Subject: Re: [PATCH v3] proc/kcore: fix invalid memory access in multi-page read optimization
Date: Tue, 4 Sep 2018 15:41:50 -0700 [thread overview]
Message-ID: <20180904224150.GD24406@vader> (raw)
In-Reply-To: <1536100702-28706-1-git-send-email-asmadeus@codewreck.org>
On Wed, Sep 05, 2018 at 12:38:22AM +0200, Dominique Martinet wrote:
> The 'm' kcore_list item could point to kclist_head, and it is incorrect to
> look at m->addr / m->size in this case.
> There is no choice but to run through the list of entries for every address
> if we did not find any entry in the previous iteration
>
> Reset 'm' to NULL in that case at Omar Sandoval's suggestion.
>
> Fixes: bf991c2231117 ("proc/kcore: optimize multiple page reads")
Reviewed-by: Omar Sandoval <osandov@fb.com>
Thanks again for catching this!
> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
> ---
>
> Sorry, resent v2 because From didn't match sob tag
>
> fs/proc/kcore.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
> index ad72261ee3fe..578926032880 100644
> --- a/fs/proc/kcore.c
> +++ b/fs/proc/kcore.c
> @@ -464,6 +464,7 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
> ret = -EFAULT;
> goto out;
> }
> + m = NULL;
> } else if (m->type == KCORE_VMALLOC) {
> vread(buf, (char *)start, tsz);
> /* we have to zero-fill user buffer even if no read */
> --
> 2.17.1
>
next prev parent reply other threads:[~2018-09-05 3:09 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-18 22:58 [PATCH v3 0/8] /proc/kcore improvements Omar Sandoval
2018-07-18 22:58 ` [PATCH v3 1/8] proc/kcore: don't grab lock for kclist_add() Omar Sandoval
2018-07-18 22:58 ` [PATCH v3 2/8] proc/kcore: don't grab lock for memory hotplug notifier Omar Sandoval
2018-07-18 22:58 ` [PATCH v3 3/8] proc/kcore: replace kclist_lock rwlock with rwsem Omar Sandoval
2018-07-18 22:58 ` [PATCH v3 4/8] proc/kcore: fix memory hotplug vs multiple opens race Omar Sandoval
2018-07-18 22:58 ` [PATCH v3 5/8] proc/kcore: hold lock during read Omar Sandoval
2018-07-24 15:11 ` Tetsuo Handa
2018-07-25 23:34 ` Omar Sandoval
2018-07-18 22:58 ` [PATCH v3 6/8] proc/kcore: clean up ELF header generation Omar Sandoval
2018-07-18 22:58 ` [PATCH v3 7/8] proc/kcore: optimize multiple page reads Omar Sandoval
2018-08-28 10:59 ` KASAN error in " Dominique Martinet
2018-08-29 4:04 ` [PATCH] proc/kcore: fix invalid memory access in multi-page read optimization Dominique Martinet
2018-09-04 18:03 ` Omar Sandoval
2018-09-04 22:24 ` Dominique Martinet
2018-09-04 22:35 ` [PATCH v2] " Dominique Martinet
2018-09-04 22:38 ` [PATCH v3] " Dominique Martinet
2018-09-04 22:41 ` Omar Sandoval [this message]
2018-09-05 19:56 ` Bhupesh Sharma
2018-09-05 20:57 ` Andrew Morton
2018-09-05 22:00 ` Dominique Martinet
2018-07-18 22:58 ` [PATCH v3 8/8] proc/kcore: add vmcoreinfo note to /proc/kcore Omar Sandoval
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