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get_compat_msghdr(): get rid of field-by-field copyin

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2017-06-27 18:24:21 -04:00
parent ffb07550c7
commit 5da028a8af
1 changed files with 14 additions and 17 deletions
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31
net/compat.c
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@ -37,21 +37,16 @@ int get_compat_msghdr(struct msghdr *kmsg,
struct sockaddr __user **save_addr, struct sockaddr __user **save_addr,
struct iovec **iov) struct iovec **iov)
{ {
compat_uptr_t uaddr, uiov, tmp3; struct compat_msghdr msg;
compat_size_t nr_segs;
ssize_t err; ssize_t err;
if (!access_ok(VERIFY_READ, umsg, sizeof(*umsg)) || if (copy_from_user(&msg, umsg, sizeof(*umsg)))
__get_user(uaddr, &umsg->msg_name) ||
__get_user(kmsg->msg_namelen, &umsg->msg_namelen) ||
__get_user(uiov, &umsg->msg_iov) ||
__get_user(nr_segs, &umsg->msg_iovlen) ||
__get_user(tmp3, &umsg->msg_control) ||
__get_user(kmsg->msg_controllen, &umsg->msg_controllen) ||
__get_user(kmsg->msg_flags, &umsg->msg_flags))
return -EFAULT; return -EFAULT;
if (!uaddr) kmsg->msg_flags = msg.msg_flags;
kmsg->msg_namelen = msg.msg_namelen;
if (!msg.msg_name)
kmsg->msg_namelen = 0; kmsg->msg_namelen = 0;
if (kmsg->msg_namelen < 0) if (kmsg->msg_namelen < 0)
@ -59,14 +54,16 @@ int get_compat_msghdr(struct msghdr *kmsg,
if (kmsg->msg_namelen > sizeof(struct sockaddr_storage)) if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
kmsg->msg_namelen = sizeof(struct sockaddr_storage); kmsg->msg_namelen = sizeof(struct sockaddr_storage);
kmsg->msg_control = compat_ptr(tmp3);
kmsg->msg_control = compat_ptr(msg.msg_control);
kmsg->msg_controllen = msg.msg_controllen;
if (save_addr) if (save_addr)
*save_addr = compat_ptr(uaddr); *save_addr = compat_ptr(msg.msg_name);
if (uaddr && kmsg->msg_namelen) { if (msg.msg_name && kmsg->msg_namelen) {
if (!save_addr) { if (!save_addr) {
err = move_addr_to_kernel(compat_ptr(uaddr), err = move_addr_to_kernel(compat_ptr(msg.msg_name),
kmsg->msg_namelen, kmsg->msg_namelen,
kmsg->msg_name); kmsg->msg_name);
if (err < 0) if (err < 0)
@ -77,13 +74,13 @@ int get_compat_msghdr(struct msghdr *kmsg,
kmsg->msg_namelen = 0; kmsg->msg_namelen = 0;
} }
if (nr_segs > UIO_MAXIOV) if (msg.msg_iovlen > UIO_MAXIOV)
return -EMSGSIZE; return -EMSGSIZE;
kmsg->msg_iocb = NULL; kmsg->msg_iocb = NULL;
return compat_import_iovec(save_addr ? READ : WRITE, return compat_import_iovec(save_addr ? READ : WRITE,
compat_ptr(uiov), nr_segs, compat_ptr(msg.msg_iov), msg.msg_iovlen,
UIO_FASTIOV, iov, &kmsg->msg_iter); UIO_FASTIOV, iov, &kmsg->msg_iter);
} }