Commit 70169420 authored Nov 17, 2016 by Eric W. Biederman

exec: Don't reset euid and egid when the tracee has CAP_SETUID



Don't reset euid and egid when the tracee has CAP_SETUID in
it's user namespace.  I punted on relaxing this permission check
long ago but now that I have read this code closely it is clear
it is safe to test against CAP_SETUID in the user namespace.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

parent 1cce1eea

security/commoncap.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -550,7 +550,7 @@ int cap_bprm_set_creds(struct linux_binprm *bprm)
		!cap_issubset(new->cap_permitted, old->cap_permitted)) &&
		bprm->unsafe & ~LSM_UNSAFE_PTRACE_CAP) {
		/* downgrade; they get no more than they had, and maybe less */
		if (!capable(CAP_SETUID) \|\|
		if (!ns_capable(new->user_ns, CAP_SETUID) \|\|
		(bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)) {
		new->euid = new->uid;
		new->egid = new->gid;