Messages in this thread Patch in this message | | | From | Ben Hutchings <> | Date | Mon, 22 Apr 2013 15:25:59 +0100 | Subject | [52/75] net: fix incorrect credentials passing |
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3.2.44-rc1 review patch. If anyone has any objections, please let me know.
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From: Linus Torvalds <torvalds@linux-foundation.org>
commit 83f1b4ba917db5dc5a061a44b3403ddb6e783494 upstream.
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> [bwh: Backported to 3.2: scm_set_cred() does user namespace conversion of euid/egid using cred_to_ucred(). Add and use cred_real_to_ucred() to do the same thing for real uid/gid.] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- include/net/scm.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- 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_real_to_ucred(pid, cred, &scm->creds); } static __inline__ void scm_destroy_cred(struct scm_cookie *scm) --- a/net/core/sock.c +++ b/net/core/sock.c @@ -761,6 +761,20 @@ void cred_to_ucred(struct pid *pid, cons } EXPORT_SYMBOL_GPL(cred_to_ucred); +void cred_real_to_ucred(struct pid *pid, const struct cred *cred, + struct ucred *ucred) +{ + 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->uid); + ucred->gid = user_ns_map_gid(current_ns, cred, cred->gid); + } +} +EXPORT_SYMBOL_GPL(cred_real_to_ucred); + int sock_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen) { --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -317,6 +317,7 @@ struct ucred { #define IPX_TYPE 1 extern void cred_to_ucred(struct pid *pid, const struct cred *cred, struct ucred *ucred); +extern void cred_real_to_ucred(struct pid *pid, const struct cred *cred, struct ucred *ucred); extern int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len); extern int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov,
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