| From 0e59f33a971304ccd9a4c84b0beb1ce969780b06 Mon Sep 17 00:00:00 2001 |
| From: Linus Torvalds <torvalds@linux-foundation.org> |
| Date: Fri, 19 Apr 2013 15:32:32 +0000 |
| Subject: net: fix incorrect credentials passing |
| |
| |
| From: Linus Torvalds <torvalds@linux-foundation.org> |
| |
| [ Upstream commit 83f1b4ba917db5dc5a061a44b3403ddb6e783494 ] |
| |
| Commit 257b5358b32f ("scm: Capture the full credentials of the scm |
| sender") changed the credentials passing code to pass in the effective |
| uid/gid instead of the real uid/gid. |
| |
| Obviously this doesn't matter most of the time (since normally they are |
| the same), but it results in differences for suid binaries when the wrong |
| uid/gid ends up being used. |
| |
| This just undoes that (presumably unintentional) part of the commit. |
| |
| Reported-by: Andy Lutomirski <luto@amacapital.net> |
| Cc: Eric W. Biederman <ebiederm@xmission.com> |
| Cc: Serge E. Hallyn <serge@hallyn.com> |
| Cc: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| include/linux/socket.h | 3 ++- |
| include/net/scm.h | 2 +- |
| net/core/sock.c | 14 ++++++++++---- |
| 3 files changed, 13 insertions(+), 6 deletions(-) |
| |
| --- a/include/linux/socket.h |
| +++ b/include/linux/socket.h |
| @@ -316,7 +316,8 @@ struct ucred { |
| /* IPX options */ |
| #define IPX_TYPE 1 |
| |
| -extern void cred_to_ucred(struct pid *pid, const struct cred *cred, struct ucred *ucred); |
| +extern void cred_to_ucred(struct pid *pid, const struct cred *cred, struct ucred *ucred, |
| + bool use_effective); |
| |
| extern int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len); |
| extern int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov, |
| --- a/include/net/scm.h |
| +++ b/include/net/scm.h |
| @@ -50,7 +50,7 @@ static __inline__ void scm_set_cred(stru |
| { |
| scm->pid = get_pid(pid); |
| scm->cred = cred ? get_cred(cred) : NULL; |
| - cred_to_ucred(pid, cred, &scm->creds); |
| + cred_to_ucred(pid, cred, &scm->creds, false); |
| } |
| |
| static __inline__ void scm_destroy_cred(struct scm_cookie *scm) |
| --- a/net/core/sock.c |
| +++ b/net/core/sock.c |
| @@ -815,15 +815,20 @@ EXPORT_SYMBOL(sock_setsockopt); |
| |
| |
| void cred_to_ucred(struct pid *pid, const struct cred *cred, |
| - struct ucred *ucred) |
| + struct ucred *ucred, bool use_effective) |
| { |
| ucred->pid = pid_vnr(pid); |
| ucred->uid = ucred->gid = -1; |
| if (cred) { |
| struct user_namespace *current_ns = current_user_ns(); |
| |
| - ucred->uid = user_ns_map_uid(current_ns, cred, cred->euid); |
| - ucred->gid = user_ns_map_gid(current_ns, cred, cred->egid); |
| + if (use_effective) { |
| + ucred->uid = user_ns_map_uid(current_ns, cred, cred->euid); |
| + ucred->gid = user_ns_map_gid(current_ns, cred, cred->egid); |
| + } else { |
| + ucred->uid = user_ns_map_uid(current_ns, cred, cred->uid); |
| + ucred->gid = user_ns_map_gid(current_ns, cred, cred->gid); |
| + } |
| } |
| } |
| EXPORT_SYMBOL_GPL(cred_to_ucred); |
| @@ -984,7 +989,8 @@ int sock_getsockopt(struct socket *sock, |
| struct ucred peercred; |
| if (len > sizeof(peercred)) |
| len = sizeof(peercred); |
| - cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred); |
| + cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, |
| + &peercred, true); |
| if (copy_to_user(optval, &peercred, len)) |
| return -EFAULT; |
| goto lenout; |