From fcea8aed91f53b51f9b943dc01f12d8aa666c720 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ernesto=20A=2E=20Fern=C3=A1ndez?= Date: Mon, 17 Jul 2017 18:42:41 +0200 Subject: [PATCH] reiserfs: preserve i_mode if __reiserfs_set_acl() fails MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When changing a file's acl mask, reiserfs_set_acl() will first set the group bits of i_mode to the value of the mask, and only then set the actual extended attribute representing the new acl. If the second part fails (due to lack of space, for example) and the file had no acl attribute to begin with, the system will from now on assume that the mask permission bits are actual group permission bits, potentially granting access to the wrong users. Prevent this by only changing the inode mode after the acl has been set. Signed-off-by: Ernesto A. Fernández Signed-off-by: Jan Kara --- fs/reiserfs/xattr_acl.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/reiserfs/xattr_acl.c b/fs/reiserfs/xattr_acl.c index d92a1dc6ee70..54415f0e3d18 100644 --- a/fs/reiserfs/xattr_acl.c +++ b/fs/reiserfs/xattr_acl.c @@ -23,7 +23,8 @@ reiserfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) struct reiserfs_transaction_handle th; size_t jcreate_blocks; int size = acl ? posix_acl_xattr_size(acl->a_count) : 0; - + int update_mode = 0; + umode_t mode = inode->i_mode; /* * Pessimism: We can't assume that anything from the xattr root up @@ -38,12 +39,14 @@ reiserfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) reiserfs_write_unlock(inode->i_sb); if (error == 0) { if (type == ACL_TYPE_ACCESS && acl) { - error = posix_acl_update_mode(inode, &inode->i_mode, - &acl); + error = posix_acl_update_mode(inode, &mode, &acl); if (error) goto unlock; + update_mode = 1; } error = __reiserfs_set_acl(&th, inode, type, acl); + if (!error && update_mode) + inode->i_mode = mode; unlock: reiserfs_write_lock(inode->i_sb); error2 = journal_end(&th); -- 2.20.1