From: Miklos Szeredi <mszeredi@redhat.com>
Date: Thu, 21 Jul 2016 20:30:58 +0000 (-0700)
Subject: vfs: add vfs_select_inode() helper
X-Git-Tag: v4.1.12-92~102^2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=5e9b8c2cf02bafdfe68ea971de0f5f37f7ced90a;p=users%2Fjedix%2Flinux-maple.git

vfs: add vfs_select_inode() helper

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org> # v4.2+

Orabug: 24363418
CVE:CVE-2016-6198,CVE-2016-6197
Based on mainline v4.6 commit 54d5ca871e72f2bb172ec9323497f01cd5091ec7
Conflicts:
  include/linux/dcache.h - code base
Signed-off-by: Chuck Anderson <chuck.anderson@oracle.com>
---

diff --git a/fs/open.c b/fs/open.c
index ff80b2542989..301c4a24c43f 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -832,16 +832,12 @@ EXPORT_SYMBOL(finish_no_open);
 int vfs_open(const struct path *path, struct file *file,
 	     const struct cred *cred)
 {
-	struct dentry *dentry = path->dentry;
-	struct inode *inode = dentry->d_inode;
+	struct inode *inode = vfs_select_inode(path->dentry, file->f_flags);
 
-	file->f_path = *path;
-	if (dentry->d_flags & DCACHE_OP_SELECT_INODE) {
-		inode = dentry->d_op->d_select_inode(dentry, file->f_flags);
-		if (IS_ERR(inode))
-			return PTR_ERR(inode);
-	}
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
 
+	file->f_path = *path;
 	return do_dentry_open(file, inode, NULL, cred);
 }
 
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index ca9df4521734..2e4217570eb0 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -576,4 +576,16 @@ static inline struct dentry *d_backing_dentry(struct dentry *upper)
 	return upper;
 }
 
+static inline struct inode *vfs_select_inode(struct dentry *dentry,
+                                            unsigned open_flags)
+{
+	struct inode *inode = d_inode(dentry);
+
+	if (inode && unlikely(dentry->d_flags & DCACHE_OP_SELECT_INODE))
+		inode = dentry->d_op->d_select_inode(dentry, open_flags);
+
+	return inode;
+}
+
+
 #endif	/* __LINUX_DCACHE_H */