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 <[email protected]>
Reviewed-by: PaX Team <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Serge Hallyn <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Emese Revfy 2013-04-17 15:58:36 -07:00 • committed by Linus Torvalds
commit b9e146d8eb

View file

@ -2948,7 +2948,7 @@ 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;