[PATCH 4.4 39/96] fs/9p: Compare qid.path in v9fs_test_inode

Greg Kroah-Hartman
2017-11-28T10:29:45Z

From: Tuomas Tynkkynen <tuomas@tuxera.com>

commit 8ee031631546cf2f7859cc69593bd60bbdd70b46 upstream.

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.")
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/9p/vfs_inode.c | 3 +++
fs/9p/vfs_inode_dotl.c | 3 +++
2 files changed, 6 insertions(+)

--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -483,6 +483,9 @@ static int v9fs_test_inode(struct inode

if (v9inode->qid.type != st->qid.type)
return 0;
+
+ if (v9inode->qid.path != st->qid.path)
+ return 0;
return 1;
}

--- 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 i

if (v9inode->qid.type != st->qid.type)
return 0;
+
+ if (v9inode->qid.path != st->qid.path)
+ return 0;
return 1;
}