fs/9p: Compare qid.path in v9fs_test_inode

Commit fd2421f54423 ("fs/9p: When doing inode lookup compare qid details
and inode mode bits.") transformed v9fs_qid_iget() to use iget5_locked()
instead of iget_locked(). However, the test() callback is not checking
fid.path at all, which means that a lookup in the inode cache can now
accidentally locate a completely wrong inode from the same inode hash
bucket if the other fields (qid.type and qid.version) match.

Fixes: fd2421f54423 ("fs/9p: When doing inode lookup compare qid details and inode mode bits.")
Cc: stable@vger.kernel.org
Reviewed-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 6 insertions, 0 deletions

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 2a5de610dd8f..bdabb2765d1b 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -483,6 +483,9 @@ static int v9fs_test_inode(struct inode *inode, void *data)
 
         if (v9inode->qid.type != st->qid.type)
                 return 0;
+
+        if (v9inode->qid.path != st->qid.path)
+                return 0;
         return 1;
 }
 
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 70f9887c59a9..7f6ae21a27b3 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -87,6 +87,9 @@ static int v9fs_test_inode_dotl(struct inode *inode, void *data)
 
         if (v9inode->qid.type != st->qid.type)
                 return 0;
+
+        if (v9inode->qid.path != st->qid.path)
+                return 0;
         return 1;
 }