c/r: prctl: add minimal address test to PR_SET_MM

Make sure the address being set is greater than mmap_min_addr (as
suggested by Kees Cook).

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/sys.c b/kernel/sys.c
index 54f20fd..19a2c71 100644 (file)
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1869,7 +1869,7 @@ static int prctl_set_mm(int opt, unsigned long addr,
        if (opt == PR_SET_MM_EXE_FILE)
                return prctl_set_mm_exe_file(mm, (unsigned int)addr);
 
-       if (addr >= TASK_SIZE)
+       if (addr >= TASK_SIZE || addr < mmap_min_addr)
                return -EINVAL;
 
        error = -EINVAL;