From: Emese Revfy <re.emese@gmail.com>
Date: Wed, 17 Apr 2013 22:58:36 +0000 (-0700)
Subject: kernel/signal.c: stop info leak via the tkill and the tgkill syscalls
X-Git-Tag: v3.0.75~19
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=aab5c5ca241d159f81e002aebb828c3c75bf4682;p=karo-tx-linux.git

kernel/signal.c: stop info leak via the tkill and the tgkill syscalls

commit b9e146d8eb3b9ecae5086d373b50fa0c1f3e7f0f upstream.

This fixes a kernel memory contents leak via the tkill and tgkill syscalls
for compat processes.

This is visible in the siginfo_t->_sifields._rt.si_sigval.sival_ptr field
when handling signals delivered from tkill.

The place of the infoleak:

int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
{
        ...
        put_user_ex(ptr_to_compat(from->si_ptr), &to->si_ptr);
        ...
}

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Reviewed-by: PaX Team <pageexec@freemail.hu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/kernel/signal.c b/kernel/signal.c
index b0c08874f09b..f15021b867fe 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2664,7 +2664,7 @@ do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info)
 
 static int do_tkill(pid_t tgid, pid_t pid, int sig)
 {
-	struct siginfo info;
+	struct siginfo info = {};
 
 	info.si_signo = sig;
 	info.si_errno = 0;