From: Brian Foster <bfoster@redhat.com>
To: Colin King <colin.king@canonical.com>
Cc: Dave Chinner <david@fromorbit.com>,
xfs@oss.sgi.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] xfs: fix null pointer dereference when mapping is NULL
Date: Thu, 3 Sep 2015 06:45:37 -0400 [thread overview]
Message-ID: <20150903104537.GA46225@bfoster.bfoster> (raw)
In-Reply-To: <1441274260-10120-1-git-send-email-colin.king@canonical.com>
On Thu, Sep 03, 2015 at 10:57:40AM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> xfs_vm_set_page_dirty checks to see if mapping is NULL however
> before this unlikely check it already dereferenced mapping when
> initializing inode. Move the inode initialization after the mapping
> null check to avoid a potential null pointer dereference.
>
> Fixes: 22e757a49cf0 ("xfs: don't dirty buffers beyond EOF")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
Reviewed-by: Brian Foster <bfoster@redhat.com>
> fs/xfs/xfs_aops.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
> index c77499b..d15ae85 100644
> --- a/fs/xfs/xfs_aops.c
> +++ b/fs/xfs/xfs_aops.c
> @@ -1935,7 +1935,7 @@ xfs_vm_set_page_dirty(
> struct page *page)
> {
> struct address_space *mapping = page->mapping;
> - struct inode *inode = mapping->host;
> + struct inode *inode;
> loff_t end_offset;
> loff_t offset;
> int newly_dirty;
> @@ -1944,6 +1944,7 @@ xfs_vm_set_page_dirty(
> if (unlikely(!mapping))
> return !TestSetPageDirty(page);
>
> + inode = mapping->host;
> end_offset = i_size_read(inode);
> offset = page_offset(page);
>
> --
> 2.5.0
>
> _______________________________________________
> xfs mailing list
> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs
next prev parent reply other threads:[~2015-09-03 10:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-03 9:57 [PATCH] xfs: fix null pointer dereference when mapping is NULL Colin King
2015-09-03 10:45 ` Brian Foster [this message]
2015-09-03 13:45 ` Eric Sandeen
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=20150903104537.GA46225@bfoster.bfoster \
--to=bfoster@redhat.com \
--cc=colin.king@canonical.com \
--cc=david@fromorbit.com \
--cc=linux-kernel@vger.kernel.org \
--cc=xfs@oss.sgi.com \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox