Commit 2e4930eb authored Aug 27, 2012 by Kees Cook Committed by James Morris Sep 08, 2012

Yama: handle 32-bit userspace prctl



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 <keescook@chromium.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>

parent c6993e4a

security/yama/yama_lsm.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -143,7 +143,7 @@ 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;

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