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authorAl Viro <viro@zeniv.linux.org.uk>2014-11-09 22:33:45 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2014-11-19 16:23:16 -0500
commit0844932009e1656726c6e9c369e694017b129378 (patch)
tree4de5bd394278e3cdf5f53c9cbc9513d1dc6fb469 /net/compat.c
parent666547ff591cebdedc4679bf6b1b3f3383a8dea3 (diff)
downloadlwn-0844932009e1656726c6e9c369e694017b129378.tar.gz
lwn-0844932009e1656726c6e9c369e694017b129378.zip
{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 <viro@zeniv.linux.org.uk>
Diffstat (limited to 'net/compat.c')
-rw-r--r--net/compat.c51
1 files changed, 15 insertions, 36 deletions
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 <asm/uaccess.h>
#include <net/compat.h>
-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... */