diff options
| author | Alexander Potapenko <glider@google.com> | 2017-04-25 18:51:46 +0200 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2017-11-06 15:29:45 +0100 |
| commit | b1c8389f8bb6563ec2d8e518b17eeaec937c63fd (patch) | |
| tree | c774486d966246775ca870e7f118e1ca36c82a14 /net/packet | |
| parent | 03691822a5914225161bfffcea41349c281571c1 (diff) | |
net/packet: check length in getsockopt() called with PACKET_HDRLEN
commit fd2c83b35752f0a8236b976978ad4658df14a59f upstream.
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: Willy Tarreau <w@1wt.eu>
Diffstat (limited to 'net/packet')
| -rw-r--r-- | net/packet/af_packet.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 00a61d683..3ef5361a8 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3364,6 +3364,8 @@ static int packet_getsockopt(struct socket *sock, int level, int optname, case PACKET_HDRLEN: if (len > sizeof(int)) len = sizeof(int); + if (len < sizeof(int)) + return -EINVAL; if (copy_from_user(&val, optval, len)) return -EFAULT; switch (val) { |