diff options
| author | Jann Horn <jann@thejh.net> | 2015-12-26 06:00:48 +0100 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-04-13 12:34:37 +0200 |
| commit | d01d5036e5f84f36c83054ec6a8195f6bc2d1991 (patch) | |
| tree | a312779d5ba24d5a901b789d0c0ea0eed1f1bd27 /kernel/seccomp.c | |
| parent | cab875d3686181dd296aaf1701598beb1d807d00 (diff) | |
UPSTREAM: seccomp: always propagate NO_NEW_PRIVS on tsync
Before this patch, a process with some permissive seccomp filter
that was applied by root without NO_NEW_PRIVS was able to add
more filters to itself without setting NO_NEW_PRIVS by setting
the new filter from a throwaway thread with NO_NEW_PRIVS.
Signed-off-by: Jann Horn <jann@thejh.net>
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Bug: 36656103
(cherry-picked from commit 103502a35cfce0710909da874f092cb44823ca03)
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Change-Id: I5abd7daab9172f1dfd53e11706b7c7f331f2f4f1
Diffstat (limited to 'kernel/seccomp.c')
| -rw-r--r-- | kernel/seccomp.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/kernel/seccomp.c b/kernel/seccomp.c index e9eff38dc..21d952a80 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -339,24 +339,24 @@ static inline void seccomp_sync_threads(void) put_seccomp_filter(thread); smp_store_release(&thread->seccomp.filter, caller->seccomp.filter); + + /* + * Don't let an unprivileged task work around + * the no_new_privs restriction by creating + * a thread that sets it up, enters seccomp, + * then dies. + */ + if (task_no_new_privs(caller)) + task_set_no_new_privs(thread); + /* * Opt the other thread into seccomp if needed. * As threads are considered to be trust-realm * equivalent (see ptrace_may_access), it is safe to * allow one thread to transition the other. */ - if (thread->seccomp.mode == SECCOMP_MODE_DISABLED) { - /* - * Don't let an unprivileged task work around - * the no_new_privs restriction by creating - * a thread that sets it up, enters seccomp, - * then dies. - */ - if (task_no_new_privs(caller)) - task_set_no_new_privs(thread); - + if (thread->seccomp.mode == SECCOMP_MODE_DISABLED) seccomp_assign_mode(thread, SECCOMP_MODE_FILTER); - } } } |