tree 5e4f34c68105b76a88b96c467be46994d70fa5f8
parent 3c00cb5e68dc719f2fc73a33b1b230aadfcb1309
author Amanieu d'Antras <amanieu@gmail.com> 1438901189 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1438911580 +0300

signal: fix information leak in copy_siginfo_to_user

This function may copy the si_addr_lsb, si_lower and si_upper fields to
user mode when they haven't been initialized, which can leak kernel
stack data to user mode.

Just checking the value of si_code is insufficient because the same
si_code value is shared between multiple signals.  This is solved by
checking the value of si_signo in addition to si_code.

Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>