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authorSage Weil <sage@newdream.net>2011-07-26 11:30:29 -0700
committerSage Weil <sage@newdream.net>2011-07-26 11:30:29 -0700
commit5f21c96dd5c615341963036ae8f5e4f5227a818d (patch)
tree898c5781623b68527427d201e3f975827d08935c /fs/ceph/inode.c
parent48d0cbd1242aac969560ef8b90f26ee3b09a6a5c (diff)
downloadlinux-5f21c96dd5c615341963036ae8f5e4f5227a818d.tar.gz
ceph: protect access to d_parent
d_parent is protected by d_lock: use it when looking up a dentry's parent
directory inode.  Also take a reference and drop it in the caller to avoid
a use-after-free.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
Diffstat (limited to 'fs/ceph/inode.c')
-rw-r--r--fs/ceph/inode.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 2717dc4e443c..a7db56f1523b 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1562,7 +1562,7 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = dentry->d_inode;
 	struct ceph_inode_info *ci = ceph_inode(inode);
-	struct inode *parent_inode = dentry->d_parent->d_inode;
+	struct inode *parent_inode;
 	const unsigned int ia_valid = attr->ia_valid;
 	struct ceph_mds_request *req;
 	struct ceph_mds_client *mdsc = ceph_sb_to_client(dentry->d_sb)->mdsc;
@@ -1745,7 +1745,9 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr)
 		req->r_inode_drop = release;
 		req->r_args.setattr.mask = cpu_to_le32(mask);
 		req->r_num_caps = 1;
+		parent_inode = ceph_get_dentry_parent_inode(dentry);
 		err = ceph_mdsc_do_request(mdsc, parent_inode, req);
+		iput(parent_inode);
 	}
 	dout("setattr %p result=%d (%s locally, %d remote)\n", inode, err,
 	     ceph_cap_string(dirtied), mask);