From: Jeff Mahoney Date: Fri, 31 May 2013 19:54:17 +0000 (-0400) Subject: reiserfs: fix problems with chowning setuid file w/ xattrs X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=4a8570112b76a63ad21cfcbe2783f98f7fd5ba1b;p=openwrt%2Fstaging%2Fblogic.git reiserfs: fix problems with chowning setuid file w/ xattrs reiserfs_chown_xattrs() takes the iattr struct passed into ->setattr and uses it to iterate over all the attrs associated with a file to change ownership of xattrs (and transfer quota associated with the xattr files). When the setuid bit is cleared during chown, ATTR_MODE and iattr->ia_mode are passed to all the xattrs as well. This means that the xattr directory will have S_IFREG added to its mode bits. This has been prevented in practice by a missing IS_PRIVATE check in reiserfs_acl_chmod, which caused a double-lock to occur while holding the write lock. Since the file system was completely locked up, the writeout of the corrupted mode never happened. This patch temporarily clears everything but ATTR_UID|ATTR_GID for the calls to reiserfs_setattr and adds the missing IS_PRIVATE check. Signed-off-by: Jeff Mahoney Signed-off-by: Jan Kara --- diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c index 4cce1d9552fb..821bcf70e467 100644 --- a/fs/reiserfs/xattr.c +++ b/fs/reiserfs/xattr.c @@ -318,7 +318,19 @@ static int delete_one_xattr(struct dentry *dentry, void *data) static int chown_one_xattr(struct dentry *dentry, void *data) { struct iattr *attrs = data; - return reiserfs_setattr(dentry, attrs); + int ia_valid = attrs->ia_valid; + int err; + + /* + * We only want the ownership bits. Otherwise, we'll do + * things like change a directory to a regular file if + * ATTR_MODE is set. + */ + attrs->ia_valid &= (ATTR_UID|ATTR_GID); + err = reiserfs_setattr(dentry, attrs); + attrs->ia_valid = ia_valid; + + return err; } /* No i_mutex, but the inode is unconnected. */ diff --git a/fs/reiserfs/xattr_acl.c b/fs/reiserfs/xattr_acl.c index d7c01ef64eda..6c8767fdfc6a 100644 --- a/fs/reiserfs/xattr_acl.c +++ b/fs/reiserfs/xattr_acl.c @@ -443,6 +443,9 @@ int reiserfs_acl_chmod(struct inode *inode) int depth; int error; + if (IS_PRIVATE(inode)) + return 0; + if (S_ISLNK(inode->i_mode)) return -EOPNOTSUPP;