From 7fa294c8991ce0ed4e713f08209eb2ce3e1044ac Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sun, 2 Sep 2012 19:12:51 -0700 Subject: [PATCH] userns: Allow chown and setgid preservation - Allow chown if CAP_CHOWN is present in the current user namespace and the uid of the inode maps into the current user namespace, and the destination uid or gid maps into the current user namespace. - Allow perserving setgid when changing an inode if CAP_FSETID is present in the current user namespace and the owner of the file has a mapping into the current user namespace. Acked-by: Serge E. Hallyn Signed-off-by: "Eric W. Biederman" --- fs/attr.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/fs/attr.c b/fs/attr.c index cce7df53b694..1449adb14ef6 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -49,14 +49,15 @@ int inode_change_ok(const struct inode *inode, struct iattr *attr) /* Make sure a caller can chown. */ if ((ia_valid & ATTR_UID) && (!uid_eq(current_fsuid(), inode->i_uid) || - !uid_eq(attr->ia_uid, inode->i_uid)) && !capable(CAP_CHOWN)) + !uid_eq(attr->ia_uid, inode->i_uid)) && + !inode_capable(inode, CAP_CHOWN)) return -EPERM; /* Make sure caller can chgrp. */ if ((ia_valid & ATTR_GID) && (!uid_eq(current_fsuid(), inode->i_uid) || (!in_group_p(attr->ia_gid) && !gid_eq(attr->ia_gid, inode->i_gid))) && - !capable(CAP_CHOWN)) + !inode_capable(inode, CAP_CHOWN)) return -EPERM; /* Make sure a caller can chmod. */ @@ -65,7 +66,8 @@ int inode_change_ok(const struct inode *inode, struct iattr *attr) return -EPERM; /* Also check the setgid bit! */ if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid : - inode->i_gid) && !capable(CAP_FSETID)) + inode->i_gid) && + !inode_capable(inode, CAP_FSETID)) attr->ia_mode &= ~S_ISGID; } @@ -157,7 +159,8 @@ void setattr_copy(struct inode *inode, const struct iattr *attr) if (ia_valid & ATTR_MODE) { umode_t mode = attr->ia_mode; - if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID)) + if (!in_group_p(inode->i_gid) && + !inode_capable(inode, CAP_FSETID)) mode &= ~S_ISGID; inode->i_mode = mode; } -- 2.34.1