linux-fsdevel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
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
> 

  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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180904224150.GD24406@vader \
    --to=osandov@osandov.com \
    --cc=adobriyan@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=asmadeus@codewreck.org \
    --cc=bhsharma@redhat.com \
    --cc=ebiederm@xmission.com \
    --cc=james.morse@arm.com \
    --cc=kernel-team@fb.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --subject='Re: [PATCH v3] proc/kcore: fix invalid memory access in multi-page read optimization' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).