From b2e4f544fddc812d6fe802bab5f600b4b783f45d Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 23 May 2012 16:39:45 -0600 Subject: userns: Convert net/core/scm.c to use kuids and kgids With the existence of kuid_t and kgid_t we can take this further and remove the usage of struct cred altogether, ensuring we don't get cache line misses from reference counts. For now however start simply and do a straight forward conversion I can be certain is correct. In cred_to_ucred use from_kuid_munged and from_kgid_munged as these values are going directly to userspace and we want to use the userspace safe values not -1 when reporting a value that does not map. The earlier conversion that used from_kuid was buggy in that respect. Oops. Cc: Eric Dumazet Acked-by: David S. Miller Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman --- net/core/scm.c | 31 +++++++++++++++++++++++-------- net/core/sock.c | 4 ++-- 2 files changed, 25 insertions(+), 10 deletions(-) (limited to 'net/core') diff --git a/net/core/scm.c b/net/core/scm.c index 8f6ccfd68ef4..5472ae7a0657 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -45,12 +45,17 @@ static __inline__ int scm_check_creds(struct ucred *creds) { const struct cred *cred = current_cred(); + kuid_t uid = make_kuid(cred->user_ns, creds->uid); + kgid_t gid = make_kgid(cred->user_ns, creds->gid); + + if (!uid_valid(uid) || !gid_valid(gid)) + return -EINVAL; if ((creds->pid == task_tgid_vnr(current) || capable(CAP_SYS_ADMIN)) && - ((creds->uid == cred->uid || creds->uid == cred->euid || - creds->uid == cred->suid) || capable(CAP_SETUID)) && - ((creds->gid == cred->gid || creds->gid == cred->egid || - creds->gid == cred->sgid) || capable(CAP_SETGID))) { + ((uid_eq(uid, cred->uid) || uid_eq(uid, cred->euid) || + uid_eq(uid, cred->suid)) || capable(CAP_SETUID)) && + ((gid_eq(gid, cred->gid) || gid_eq(gid, cred->egid) || + gid_eq(gid, cred->sgid)) || capable(CAP_SETGID))) { return 0; } return -EPERM; @@ -149,6 +154,9 @@ int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p) goto error; break; case SCM_CREDENTIALS: + { + kuid_t uid; + kgid_t gid; if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct ucred))) goto error; memcpy(&p->creds, CMSG_DATA(cmsg), sizeof(struct ucred)); @@ -166,22 +174,29 @@ int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p) p->pid = pid; } + err = -EINVAL; + uid = make_kuid(current_user_ns(), p->creds.uid); + gid = make_kgid(current_user_ns(), p->creds.gid); + if (!uid_valid(uid) || !gid_valid(gid)) + goto error; + if (!p->cred || - (p->cred->euid != p->creds.uid) || - (p->cred->egid != p->creds.gid)) { + !uid_eq(p->cred->euid, uid) || + !gid_eq(p->cred->egid, gid)) { struct cred *cred; err = -ENOMEM; cred = prepare_creds(); if (!cred) goto error; - cred->uid = cred->euid = p->creds.uid; - cred->gid = cred->egid = p->creds.gid; + cred->uid = cred->euid = uid; + cred->gid = cred->egid = gid; if (p->cred) put_cred(p->cred); p->cred = cred; } break; + } default: goto error; } diff --git a/net/core/sock.c b/net/core/sock.c index 6b654b3ddfda..9c7fe4ff30fc 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -868,8 +868,8 @@ void cred_to_ucred(struct pid *pid, const struct cred *cred, if (cred) { struct user_namespace *current_ns = current_user_ns(); - ucred->uid = from_kuid(current_ns, cred->euid); - ucred->gid = from_kgid(current_ns, cred->egid); + ucred->uid = from_kuid_munged(current_ns, cred->euid); + ucred->gid = from_kgid_munged(current_ns, cred->egid); } } EXPORT_SYMBOL_GPL(cred_to_ucred); -- cgit v1.2.3 From d04a48b06d63b6d6e9289ca8a5e6e84ebfe39bfd Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 23 May 2012 17:01:57 -0600 Subject: userns: Convert __dev_set_promiscuity to use kuids in audit logs Cc: Klaus Heinrich Kiwi Cc: Eric Paris Acked-by: David S. Miller Acked-by: Serge Hallyn Signed-off-by: "Eric W. Biederman" --- net/core/dev.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'net/core') diff --git a/net/core/dev.c b/net/core/dev.c index 0cb3fe8d8e72..026bb4a37665 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4492,8 +4492,8 @@ static void dev_change_rx_flags(struct net_device *dev, int flags) static int __dev_set_promiscuity(struct net_device *dev, int inc) { unsigned int old_flags = dev->flags; - uid_t uid; - gid_t gid; + kuid_t uid; + kgid_t gid; ASSERT_RTNL(); @@ -4525,7 +4525,8 @@ static int __dev_set_promiscuity(struct net_device *dev, int inc) dev->name, (dev->flags & IFF_PROMISC), (old_flags & IFF_PROMISC), audit_get_loginuid(current), - uid, gid, + from_kuid(&init_user_ns, uid), + from_kgid(&init_user_ns, gid), audit_get_sessionid(current)); } -- cgit v1.2.3 From 976d020150456fccbd34103fd117fab910eed09c Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 23 May 2012 17:16:53 -0600 Subject: userns: Convert sock_i_uid to return a kuid_t Acked-by: David S. Miller Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman --- net/core/sock.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net/core') diff --git a/net/core/sock.c b/net/core/sock.c index 9c7fe4ff30fc..5c6a435717e0 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1526,12 +1526,12 @@ void sock_edemux(struct sk_buff *skb) } EXPORT_SYMBOL(sock_edemux); -int sock_i_uid(struct sock *sk) +kuid_t sock_i_uid(struct sock *sk) { - int uid; + kuid_t uid; read_lock_bh(&sk->sk_callback_lock); - uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : 0; + uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID; read_unlock_bh(&sk->sk_callback_lock); return uid; } -- cgit v1.2.3