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| author | Alexander Potapenko <glider@google.com> | 2017-04-25 19:51:46 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-10-08 11:26:08 +0300 |
| commit | 897e8c528529f5b53d1a63bbac3802adf5e09170 (patch) | |
| tree | 240d5fd8a5a70e4e29d7646c268337dcfde66fde /net/packet | |
| parent | 1dee03af7325f8a04954f9114cb76945fddb950c (diff) | |
| download | linux-897e8c528529f5b53d1a63bbac3802adf5e09170.tar.xz | |
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>
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 35ba4b60d927..9c92c6cb6a4f 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3884,6 +3884,8 @@ 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) { |