Yama: handle 32-bit userspace prctl
authorKees Cook <keescook@chromium.org>
Mon, 27 Aug 2012 18:38:13 +0000 (11:38 -0700)
committerJames Morris <james.l.morris@oracle.com>
Fri, 7 Sep 2012 15:06:14 +0000 (01:06 +1000)
commit2e4930eb7c8fb20a39dfb5f8a8f80402710dcea8
tree01e5e84032b2d7efe3441080e5ce1c484f696680
parentc6993e4ac002c92bc75379212e9179c36d4bf7ee
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>
security/yama/yama_lsm.c