From: Eric Sandeen <sandeen@sandeen.net>
To: Brian Foster <bfoster@redhat.com>, Colin King <colin.king@canonical.com>
Cc: linux-kernel@vger.kernel.org, xfs@oss.sgi.com
Subject: Re: [PATCH] xfs: fix null pointer dereference when mapping is NULL
Date: Thu, 3 Sep 2015 08:45:02 -0500 [thread overview]
Message-ID: <55E84EDE.2080404@sandeen.net> (raw)
In-Reply-To: <20150903104537.GA46225@bfoster.bfoster>
On 9/3/15 5:45 AM, Brian Foster wrote:
> 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>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Should probably cc: stable on this one too, the commit it
fixes went in at 3.17, and it also cc'd stable.
-Eric
>> 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
>
> _______________________________________________
> xfs mailing list
> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs
>
prev parent reply other threads:[~2015-09-03 13:50 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
2015-09-03 13:45 ` Eric Sandeen [this message]
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=55E84EDE.2080404@sandeen.net \
--to=sandeen@sandeen.net \
--cc=bfoster@redhat.com \
--cc=colin.king@canonical.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