From 20523132ec5d1b481e1d66557292ed3a3021e817 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 23 Jan 2017 17:17:26 +1300 Subject: [PATCH] exec: Test the ptracer's saved cred to see if the tracee can gain caps Now that we have user namespaces and non-global capabilities verify the tracer has capabilities in the relevant user namespace instead of in the current_user_ns(). As the test for setting LSM_UNSAFE_PTRACE_CAP is currently ptracer_capable(p, current_user_ns()) and the new task credentials are in current_user_ns() this change does not have any user visible change and simply moves the test to where it is used, making the code easier to read. Signed-off-by: "Eric W. Biederman" --- security/commoncap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/security/commoncap.c b/security/commoncap.c index feb6044f701d..cbb203c91406 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -548,7 +548,8 @@ skip: if ((is_setid || !cap_issubset(new->cap_permitted, old->cap_permitted)) && - bprm->unsafe & ~LSM_UNSAFE_PTRACE_CAP) { + ((bprm->unsafe & ~(LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) || + !ptracer_capable(current, new->user_ns))) { /* downgrade; they get no more than they had, and maybe less */ if (!ns_capable(new->user_ns, CAP_SETUID) || (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)) { -- 2.20.1