Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [ 33/34] net: fix incorrect credentials passing | Date | Mon, 29 Apr 2013 12:02:40 -0700 |
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3.4-stable review patch. If anyone has any objections, please let me know.
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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;
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