From 7d0fcfec4c491eb3c815929be5512ae8d1886553 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 27 Aug 2012 11:38:13 -0700 Subject: [PATCH] Yama: handle 32-bit userspace prctl commit 2e4930eb7c8fb20a39dfb5f8a8f80402710dcea8 upstream. When running a 64-bit kernel and receiving prctls from a 32-bit userspace, the "-1" used as an unsigned long will end up being misdetected. The kernel is looking for 0xffffffffffffffff instead of 0xffffffff. Since prctl lacks a distinct compat interface, Yama needs to handle this translation itself. As such, support either value as meaning PR_SET_PTRACER_ANY, to avoid breaking the ABI for 64-bit. Signed-off-by: Kees Cook Acked-by: John Johansen Signed-off-by: James Morris Signed-off-by: Greg Kroah-Hartman --- security/yama/yama_lsm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c index 5737238..1d6bf24 100644 --- a/security/yama/yama_lsm.c +++ b/security/yama/yama_lsm.c @@ -138,7 +138,7 @@ static int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3, if (arg2 == 0) { yama_ptracer_del(NULL, myself); rc = 0; - } else if (arg2 == PR_SET_PTRACER_ANY) { + } else if (arg2 == PR_SET_PTRACER_ANY || (int)arg2 == -1) { rc = yama_ptracer_add(NULL, myself); } else { struct task_struct *tracer; -- 2.7.4