From dbe9a4173ea53b72b2c35d19f676a85b69f1c9fe Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 6 Sep 2012 18:20:01 +0000 Subject: scm: Don't use struct ucred in NETLINK_CB and struct scm_cookie. Passing uids and gids on NETLINK_CB from a process in one user namespace to a process in another user namespace can result in the wrong uid or gid being presented to userspace. Avoid that problem by passing kuids and kgids instead. - define struct scm_creds for use in scm_cookie and netlink_skb_parms that holds uid and gid information in kuid_t and kgid_t. - Modify scm_set_cred to fill out scm_creds by heand instead of using cred_to_ucred to fill out struct ucred. This conversion ensures userspace does not get incorrect uid or gid values to look at. - Modify scm_recv to convert from struct scm_creds to struct ucred before copying credential values to userspace. - Modify __scm_send to populate struct scm_creds on in the scm_cookie, instead of just copying struct ucred from userspace. - Modify netlink_sendmsg to copy scm_creds instead of struct ucred into the NETLINK_CB. Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller --- include/linux/netlink.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/netlink.h') diff --git a/include/linux/netlink.h b/include/linux/netlink.h index c9fdde2bc73f..df73cf4b0290 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -153,6 +153,7 @@ struct nlattr { #include #include +#include struct net; @@ -162,7 +163,7 @@ static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb) } struct netlink_skb_parms { - struct ucred creds; /* Skb credentials */ + struct scm_creds creds; /* Skb credentials */ __u32 pid; __u32 dst_group; struct sock *ssk; -- cgit v1.2.3