From 0844932009e1656726c6e9c369e694017b129378 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 9 Nov 2014 22:33:45 -0500 Subject: {compat_,}verify_iovec(): switch to generic copying of iovecs use {compat_,}rw_copy_check_uvector(). As the result, we are guaranteed that all iovecs seen in ->msg_iov by ->sendmsg() and ->recvmsg() will pass access_ok(). Signed-off-by: Al Viro --- net/compat.c | 51 +++++++++++++++------------------------------------ 1 file changed, 15 insertions(+), 36 deletions(-) (limited to 'net/compat.c') diff --git a/net/compat.c b/net/compat.c index 562e920b07f0..7b4b6ad13235 100644 --- a/net/compat.c +++ b/net/compat.c @@ -31,33 +31,6 @@ #include #include -static inline int iov_from_user_compat_to_kern(struct iovec *kiov, - struct compat_iovec __user *uiov32, - int niov) -{ - int tot_len = 0; - - while (niov > 0) { - compat_uptr_t buf; - compat_size_t len; - - if (get_user(len, &uiov32->iov_len) || - get_user(buf, &uiov32->iov_base)) - return -EFAULT; - - if (len > INT_MAX - tot_len) - len = INT_MAX - tot_len; - - tot_len += len; - kiov->iov_base = compat_ptr(buf); - kiov->iov_len = (__kernel_size_t) len; - uiov32++; - kiov++; - niov--; - } - return tot_len; -} - int get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg) { compat_uptr_t tmp1, tmp2, tmp3; @@ -80,13 +53,15 @@ int get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg) } /* I've named the args so it is easy to tell whose space the pointers are in. */ -int verify_compat_iovec(struct msghdr *kern_msg, struct iovec *kern_iov, +int verify_compat_iovec(struct msghdr *kern_msg, struct iovec *iov, struct sockaddr_storage *kern_address, int mode) { - int tot_len; + struct compat_iovec __user *p; + struct iovec *res; + int err; if (kern_msg->msg_name && kern_msg->msg_namelen) { - if (mode == VERIFY_READ) { + if (mode == WRITE) { int err = move_addr_to_kernel(kern_msg->msg_name, kern_msg->msg_namelen, kern_address); @@ -99,13 +74,17 @@ int verify_compat_iovec(struct msghdr *kern_msg, struct iovec *kern_iov, kern_msg->msg_namelen = 0; } - tot_len = iov_from_user_compat_to_kern(kern_iov, - (struct compat_iovec __user *)kern_msg->msg_iov, - kern_msg->msg_iovlen); - if (tot_len >= 0) - kern_msg->msg_iov = kern_iov; + if (kern_msg->msg_iovlen > UIO_MAXIOV) + return -EMSGSIZE; - return tot_len; + p = (struct compat_iovec __user *)kern_msg->msg_iov; + err = compat_rw_copy_check_uvector(mode, p, kern_msg->msg_iovlen, + UIO_FASTIOV, iov, &res); + if (err >= 0) + kern_msg->msg_iov = res; + else if (res != iov) + kfree(res); + return err; } /* Bleech... */ -- cgit v1.2.3-55-g7522