switch cmsghdr_from_user_compat_to_kern() to copy_from_user()

no point getting compat_cmsghdr field-by-field

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Al Viro 2020-05-31 02:06:55 +01:00 committed by David S. Miller
parent a477605fdb
commit 547ce4cfb3
1 changed files with 8 additions and 7 deletions

View File

@ -183,20 +183,21 @@ int cmsghdr_from_user_compat_to_kern(struct msghdr *kmsg, struct sock *sk,
memset(kcmsg, 0, kcmlen);
ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
while (ucmsg != NULL) {
if (__get_user(ucmlen, &ucmsg->cmsg_len))
struct compat_cmsghdr cmsg;
if (copy_from_user(&cmsg, ucmsg, sizeof(cmsg)))
goto Efault;
if (!CMSG_COMPAT_OK(ucmlen, ucmsg, kmsg))
if (!CMSG_COMPAT_OK(cmsg.cmsg_len, ucmsg, kmsg))
goto Einval;
tmp = ((ucmlen - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
tmp = ((cmsg.cmsg_len - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
if ((char *)kcmsg_base + kcmlen - (char *)kcmsg < CMSG_ALIGN(tmp))
goto Einval;
kcmsg->cmsg_len = tmp;
kcmsg->cmsg_level = cmsg.cmsg_level;
kcmsg->cmsg_type = cmsg.cmsg_type;
tmp = CMSG_ALIGN(tmp);
if (__get_user(kcmsg->cmsg_level, &ucmsg->cmsg_level) ||
__get_user(kcmsg->cmsg_type, &ucmsg->cmsg_type) ||
copy_from_user(CMSG_DATA(kcmsg),
if (copy_from_user(CMSG_DATA(kcmsg),
CMSG_COMPAT_DATA(ucmsg),
(ucmlen - sizeof(*ucmsg))))
(cmsg.cmsg_len - sizeof(*ucmsg))))
goto Efault;
/* Advance. */