* [PATCH] NFS: fix potential NULL deref in nfs_closedir()
@ 2015-03-21 4:21 Taesoo Kim
2015-03-21 18:01 ` Christoph Hellwig
0 siblings, 1 reply; 3+ messages in thread
From: Taesoo Kim @ 2015-03-21 4:21 UTC (permalink / raw)
To: trond.myklebust, anna.schumaker, linux-nfs, linux-kernel
Cc: taesoo, changwoo, sanidhya, blee, csong84, Byoungyoung Lee,
Taesoo Kim
From: Byoungyoung Lee <lifeasageek@gmail.com>
When filp->private_data is NULL, put_nfs_open_dir_context()
deferences its pointer (fi->list, fi->cred), similar to what
other file systems handle '.release' api (9p, cifs, btrfs,
ext4, ocfs2).
Signed-off-by: Byoungyoung Lee <lifeasageek@gmail.com>
Signed-off-by: Taesoo Kim <tsgatesv@gmail.com>
---
fs/nfs/dir.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index c19e16f..434ecf1 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -133,7 +133,8 @@ out:
static int
nfs_closedir(struct inode *inode, struct file *filp)
{
- put_nfs_open_dir_context(file_inode(filp), filp->private_data);
+ if (filp->private_data)
+ put_nfs_open_dir_context(file_inode(filp), filp->private_data);
return 0;
}
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] NFS: fix potential NULL deref in nfs_closedir()
2015-03-21 4:21 [PATCH] NFS: fix potential NULL deref in nfs_closedir() Taesoo Kim
@ 2015-03-21 18:01 ` Christoph Hellwig
2015-03-21 18:47 ` Taesoo Kim
0 siblings, 1 reply; 3+ messages in thread
From: Christoph Hellwig @ 2015-03-21 18:01 UTC (permalink / raw)
To: Taesoo Kim
Cc: trond.myklebust, anna.schumaker, linux-nfs, linux-kernel, taesoo,
changwoo, sanidhya, blee, csong84, Byoungyoung Lee
On Sat, Mar 21, 2015 at 12:21:18AM -0400, Taesoo Kim wrote:
> From: Byoungyoung Lee <lifeasageek@gmail.com>
>
> When filp->private_data is NULL, put_nfs_open_dir_context()
> deferences its pointer (fi->list, fi->cred), similar to what
> other file systems handle '.release' api (9p, cifs, btrfs,
> ext4, ocfs2).
Why woud filp->private_data ever be NULL here?
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] NFS: fix potential NULL deref in nfs_closedir()
2015-03-21 18:01 ` Christoph Hellwig
@ 2015-03-21 18:47 ` Taesoo Kim
0 siblings, 0 replies; 3+ messages in thread
From: Taesoo Kim @ 2015-03-21 18:47 UTC (permalink / raw)
To: Christoph Hellwig
Cc: Taesoo Kim, trond.myklebust, anna.schumaker, linux-nfs,
linux-kernel, changwoo, sanidhya, blee, csong84, Byoungyoung Lee
Ops. After reading nfs code, we also find out that nfs_opendir()
always allocates ctx obj (for private_data), unlike other fs allocate
private_data right before seeking dentries.
Sorry for the false alarm.
Taesoo
On 03/21/15 at 11:01am, Christoph Hellwig wrote:
> On Sat, Mar 21, 2015 at 12:21:18AM -0400, Taesoo Kim wrote:
> > From: Byoungyoung Lee <lifeasageek@gmail.com>
> >
> > When filp->private_data is NULL, put_nfs_open_dir_context()
> > deferences its pointer (fi->list, fi->cred), similar to what
> > other file systems handle '.release' api (9p, cifs, btrfs,
> > ext4, ocfs2).
>
> Why woud filp->private_data ever be NULL here?
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2015-03-21 18:47 UTC | newest]
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2015-03-21 4:21 [PATCH] NFS: fix potential NULL deref in nfs_closedir() Taesoo Kim
2015-03-21 18:01 ` Christoph Hellwig
2015-03-21 18:47 ` Taesoo Kim
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