diff options
| author | Miklos Szeredi <mszeredi@redhat.com> | 2016-07-01 14:56:07 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-10 11:49:27 +0200 |
| commit | a3bdfa7b6185c677921df51cd2e44ab8aa656a2d (patch) | |
| tree | 1a507d668e7e9b9d8f956a99d3ce4998c4566e1b /fs/locks.c | |
| parent | acbda596b5cdf4784938fe6feca43b28c2dc8a53 (diff) | |
| download | lwn-a3bdfa7b6185c677921df51cd2e44ab8aa656a2d.tar.gz lwn-a3bdfa7b6185c677921df51cd2e44ab8aa656a2d.zip | |
locks: use file_inode()
commit 6343a2120862f7023006c8091ad95c1f16a32077 upstream.
(Another one for the f_path debacle.)
ltp fcntl33 testcase caused an Oops in selinux_file_send_sigiotask.
The reason is that generic_add_lease() used filp->f_path.dentry->inode
while all the others use file_inode(). This makes a difference for files
opened on overlayfs since the former will point to the overlay inode the
latter to the underlying inode.
So generic_add_lease() added the lease to the overlay inode and
generic_delete_lease() removed it from the underlying inode. When the file
was released the lease remained on the overlay inode's lock list, resulting
in use after free.
Reported-by: Eryu Guan <eguan@redhat.com>
Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/locks.c')
| -rw-r--r-- | fs/locks.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/locks.c b/fs/locks.c index 6333263b7bc8..8eddae23e10b 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1602,7 +1602,7 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr { struct file_lock *fl, *my_fl = NULL, *lease; struct dentry *dentry = filp->f_path.dentry; - struct inode *inode = dentry->d_inode; + struct inode *inode = file_inode(filp); struct file_lock_context *ctx; bool is_deleg = (*flp)->fl_flags & FL_DELEG; int error; |