+ signal-stop-info-leak-via-the-tkill-and-the-tgkill-syscalls.patch added to -mm tree

[akpm@xxxxxxxxxxxxxxxxxxxx]

The patch titled
     Subject: kernel/signal.c: stop info leak via the tkill and the tgkill syscalls
has been added to the -mm tree.  Its filename is
     signal-stop-info-leak-via-the-tkill-and-the-tgkill-syscalls.patch

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------------------------------------------------------
From: Emese Revfy <re.emese@xxxxxxxxx>
Subject: kernel/signal.c: stop info leak via the tkill and the tgkill syscalls

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@xxxxxxxxx>
Reviewed-by: PaX Team <pageexec@xxxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Serge Hallyn <serge.hallyn@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 kernel/signal.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN kernel/signal.c~signal-stop-info-leak-via-the-tkill-and-the-tgkill-syscalls kernel/signal.c
--- a/kernel/signal.c~signal-stop-info-leak-via-the-tkill-and-the-tgkill-syscalls
+++ a/kernel/signal.c
@@ -2949,7 +2949,7 @@ do_send_specific(pid_t tgid, pid_t pid,
 
 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;
_

Patches currently in -mm which might be from re.emese@xxxxxxxxx are

signal-stop-info-leak-via-the-tkill-and-the-tgkill-syscalls.patch

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