[065/126] kernel/signal.c: stop info leak via the tkill and the tgkill syscalls

Steven Rostedt
2013-05-07T04:29:46Z

[-- Attachment #1: 0065-kernel-signal.c-stop-info-leak-via-the-tkill-and-the.patch --]
[-- Type: text/plain, Size: 1586 bytes --]

3.6.11.3 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Emese Revfy <re.emese@gmail.com>

[ Upstream commit b9e146d8eb3b9ecae5086d373b50fa0c1f3e7f0f ]

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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
kernel/signal.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index be4f856..6b9b817 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2898,7 +2898,7 @@ 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;
--
1.7.10.4