From: Kees Cook Date: Mon, 27 Aug 2012 18:38:13 +0000 (-0700) Subject: Yama: handle 32-bit userspace prctl X-Git-Tag: v3.5.6~13 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1a260a55cd19b1dc22040a9f4dd9ee995bd38504;p=thirdparty%2Fkernel%2Fstable.git 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 --- diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c index 0cc99a3ea42d6..dcd617829fae5 100644 --- a/security/yama/yama_lsm.c +++ b/security/yama/yama_lsm.c @@ -143,7 +143,7 @@ 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;