tree 240d5fd8a5a70e4e29d7646c268337dcfde66fde
parent 1dee03af7325f8a04954f9114cb76945fddb950c
author Alexander Potapenko <glider@google.com> 1493139106 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1507451168 +0200

net/packet: check length in getsockopt() called with PACKET_HDRLEN


[ Upstream commit fd2c83b35752f0a8236b976978ad4658df14a59f ]

In the case getsockopt() is called with PACKET_HDRLEN and optlen < 4
|val| remains uninitialized and the syscall may behave differently
depending on its value, and even copy garbage to userspace on certain
architectures. To fix this we now return -EINVAL if optlen is too small.

This bug has been detected with KMSAN.

Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>