[ Upstream commit f2aeb7306a898e1cbd03963d376f4b6656ca2b55 ]
Since 'ppp_async_encode()' assumes valid LCP packets (with code
from 1 to 7 inclusive), add 'ppp_check_packet()' to ensure that
LCP packet has an actual body beyond PPP_LCP header bytes, and
reject claimed-as-LCP but actually malformed data otherwise.
Reported-by: syzbot+ec0723ba9605678b14bf@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=ec0723ba9605678b14bf
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
70e0603b6e