diff options
| author | David S. Miller | 2017-01-04 13:24:19 -0500 |
|---|---|---|
| committer | David S. Miller | 2017-01-04 13:24:19 -0500 |
| commit | ac4340fc3ce0e0b1cb627b05d6dcbd473544d7b3 (patch) | |
| tree | 4987c1a7d7ce5273097bab8debde9ba2fde343ee | |
| parent | 1ff8cebf49ed9e9ca2ae44b5c4176aef9c21af9c (diff) | |
net: Assert at build time the assumptions we make about the CMSG header.
It must always be the case that CMSG_ALIGN(sizeof(hdr)) == sizeof(hdr).
Otherwise there are missing adjustments in the various calculations
that parse and build these things.
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/compat.c | 3 | ||||
| -rw-r--r-- | net/socket.c | 2 |
2 files changed, 5 insertions, 0 deletions
diff --git a/net/compat.c b/net/compat.c index 4e27dd1cd3a6..ba3ac722714d 100644 --- a/net/compat.c +++ b/net/compat.c @@ -130,6 +130,9 @@ int cmsghdr_from_user_compat_to_kern(struct msghdr *kmsg, struct sock *sk, __kernel_size_t kcmlen, tmp; int err = -EFAULT; + BUILD_BUG_ON(sizeof(struct compat_cmsghdr) != + CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr))); + kcmlen = 0; kcmsg_base = kcmsg = (struct cmsghdr *)stackbuf; ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg); diff --git a/net/socket.c b/net/socket.c index 8487bf136e5c..5f3b5a2c4f37 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1948,6 +1948,8 @@ static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg, ctl_buf = msg_sys->msg_control; ctl_len = msg_sys->msg_controllen; } else if (ctl_len) { + BUILD_BUG_ON(sizeof(struct cmsghdr) != + CMSG_ALIGN(sizeof(struct cmsghdr))); if (ctl_len > sizeof(ctl)) { ctl_buf = sock_kmalloc(sock->sk, ctl_len, GFP_KERNEL); if (ctl_buf == NULL) |