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Message-ID: <20141118194345.GF14641@ZenIV.linux.org.uk>
Date: Tue, 18 Nov 2014 19:43:45 +0000
From: Al Viro <viro@...IV.linux.org.uk>
To: netdev@...r.kernel.org
Cc: Linus Torvalds <torvalds@...ux-foundation.org>,
David Miller <davem@...emloft.net>,
linux-kernel@...r.kernel.org
Subject: [PATCH 5/5] fold verify_iovec() into copy_msghdr_from_user()
... and do the same on the compat side of things.
Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
---
include/linux/socket.h | 1 -
include/net/compat.h | 5 ++-
net/compat.c | 52 ++++++++++++---------------
net/core/iovec.c | 38 --------------------
net/socket.c | 93 +++++++++++++++++++++++++++---------------------
5 files changed, 77 insertions(+), 112 deletions(-)
diff --git a/include/linux/socket.h b/include/linux/socket.h
index 51bd666..de52228 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -322,7 +322,6 @@ extern int csum_partial_copy_fromiovecend(unsigned char *kdata,
extern unsigned long iov_pages(const struct iovec *iov, int offset,
unsigned long nr_segs);
-extern int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr_storage *address, int mode);
extern int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr_storage *kaddr);
extern int put_cmsg(struct msghdr*, int level, int type, int len, void *data);
diff --git a/include/net/compat.h b/include/net/compat.h
index 3b603b1..42a9c84 100644
--- a/include/net/compat.h
+++ b/include/net/compat.h
@@ -40,9 +40,8 @@ int compat_sock_get_timestampns(struct sock *, struct timespec __user *);
#define compat_mmsghdr mmsghdr
#endif /* defined(CONFIG_COMPAT) */
-int get_compat_msghdr(struct msghdr *, struct compat_msghdr __user *);
-int verify_compat_iovec(struct msghdr *, struct iovec *,
- struct sockaddr_storage *, int);
+ssize_t get_compat_msghdr(struct msghdr *, struct compat_msghdr __user *,
+ struct sockaddr __user **, struct iovec **);
asmlinkage long compat_sys_sendmsg(int, struct compat_msghdr __user *,
unsigned int);
asmlinkage long compat_sys_sendmmsg(int, struct compat_mmsghdr __user *,
diff --git a/net/compat.c b/net/compat.c
index 7b4b6ad..062f157 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -31,14 +31,18 @@
#include <asm/uaccess.h>
#include <net/compat.h>
-int get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg)
+ssize_t get_compat_msghdr(struct msghdr *kmsg,
+ struct compat_msghdr __user *umsg,
+ struct sockaddr __user **save_addr,
+ struct iovec **iov)
{
- compat_uptr_t tmp1, tmp2, tmp3;
+ compat_uptr_t uaddr, uiov, tmp3;
+ ssize_t err;
if (!access_ok(VERIFY_READ, umsg, sizeof(*umsg)) ||
- __get_user(tmp1, &umsg->msg_name) ||
+ __get_user(uaddr, &umsg->msg_name) ||
__get_user(kmsg->msg_namelen, &umsg->msg_namelen) ||
- __get_user(tmp2, &umsg->msg_iov) ||
+ __get_user(uiov, &umsg->msg_iov) ||
__get_user(kmsg->msg_iovlen, &umsg->msg_iovlen) ||
__get_user(tmp3, &umsg->msg_control) ||
__get_user(kmsg->msg_controllen, &umsg->msg_controllen) ||
@@ -46,44 +50,32 @@ int get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg)
return -EFAULT;
if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
kmsg->msg_namelen = sizeof(struct sockaddr_storage);
- kmsg->msg_name = compat_ptr(tmp1);
- kmsg->msg_iov = compat_ptr(tmp2);
kmsg->msg_control = compat_ptr(tmp3);
- return 0;
-}
-/* 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 *iov,
- struct sockaddr_storage *kern_address, int mode)
-{
- struct compat_iovec __user *p;
- struct iovec *res;
- int err;
+ if (save_addr)
+ *save_addr = compat_ptr(uaddr);
- if (kern_msg->msg_name && kern_msg->msg_namelen) {
- if (mode == WRITE) {
- int err = move_addr_to_kernel(kern_msg->msg_name,
- kern_msg->msg_namelen,
- kern_address);
+ if (uaddr && kmsg->msg_namelen) {
+ if (!save_addr) {
+ err = move_addr_to_kernel(compat_ptr(uaddr),
+ kmsg->msg_namelen,
+ kmsg->msg_name);
if (err < 0)
return err;
}
- kern_msg->msg_name = kern_address;
} else {
- kern_msg->msg_name = NULL;
- kern_msg->msg_namelen = 0;
+ kmsg->msg_name = NULL;
+ kmsg->msg_namelen = 0;
}
- if (kern_msg->msg_iovlen > UIO_MAXIOV)
+ if (kmsg->msg_iovlen > UIO_MAXIOV)
return -EMSGSIZE;
- 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);
+ err = compat_rw_copy_check_uvector(save_addr ? READ : WRITE,
+ compat_ptr(uiov), kmsg->msg_iovlen,
+ UIO_FASTIOV, *iov, iov);
if (err >= 0)
- kern_msg->msg_iov = res;
- else if (res != iov)
- kfree(res);
+ kmsg->msg_iov = *iov;
return err;
}
diff --git a/net/core/iovec.c b/net/core/iovec.c
index 4a35b21..fa3eed9 100644
--- a/net/core/iovec.c
+++ b/net/core/iovec.c
@@ -28,44 +28,6 @@
#include <net/sock.h>
/*
- * Verify iovec. The caller must ensure that the iovec is big enough
- * to hold the message iovec.
- *
- * Save time not doing access_ok. copy_*_user will make this work
- * in any case.
- */
-
-int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr_storage *address, int mode)
-{
- struct iovec *res;
- int err;
-
- if (m->msg_name && m->msg_namelen) {
- if (mode == WRITE) {
- void __user *namep = (void __user __force *)m->msg_name;
- int err = move_addr_to_kernel(namep, m->msg_namelen,
- address);
- if (err < 0)
- return err;
- }
- m->msg_name = address;
- } else {
- m->msg_name = NULL;
- m->msg_namelen = 0;
- }
- if (m->msg_iovlen > UIO_MAXIOV)
- return -EMSGSIZE;
-
- err = rw_copy_check_uvector(mode, (void __user __force *)m->msg_iov,
- m->msg_iovlen, UIO_FASTIOV, iov, &res);
- if (err >= 0)
- m->msg_iov = res;
- else if (res != iov)
- kfree(res);
- return err;
-}
-
-/*
* And now for the all-in-one: copy and checksum from a user iovec
* directly to a datagram
* Calls to csum_partial but the last must be in 32 bit chunks
diff --git a/net/socket.c b/net/socket.c
index 59020f0..ee3ee39 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1988,16 +1988,26 @@ struct used_address {
unsigned int name_len;
};
-static int copy_msghdr_from_user(struct msghdr *kmsg,
- struct user_msghdr __user *umsg)
+static ssize_t copy_msghdr_from_user(struct msghdr *kmsg,
+ struct user_msghdr __user *umsg,
+ struct sockaddr __user **save_addr,
+ struct iovec **iov)
{
- /* We are relying on the (currently) identical layouts. Once
- * the kernel-side changes, this place will need to be updated
- */
- if (copy_from_user(kmsg, umsg, sizeof(struct msghdr)))
+ struct sockaddr __user *uaddr;
+ struct iovec __user *uiov;
+ ssize_t err;
+
+ if (!access_ok(VERIFY_READ, 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(kmsg->msg_iovlen, &umsg->msg_iovlen) ||
+ __get_user(kmsg->msg_control, &umsg->msg_control) ||
+ __get_user(kmsg->msg_controllen, &umsg->msg_controllen) ||
+ __get_user(kmsg->msg_flags, &umsg->msg_flags))
return -EFAULT;
- if (kmsg->msg_name == NULL)
+ if (!uaddr)
kmsg->msg_namelen = 0;
if (kmsg->msg_namelen < 0)
@@ -2005,7 +2015,31 @@ static int copy_msghdr_from_user(struct msghdr *kmsg,
if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
kmsg->msg_namelen = sizeof(struct sockaddr_storage);
- return 0;
+
+ if (save_addr)
+ *save_addr = uaddr;
+
+ if (uaddr && kmsg->msg_namelen) {
+ if (!save_addr) {
+ err = move_addr_to_kernel(uaddr, kmsg->msg_namelen,
+ kmsg->msg_name);
+ if (err < 0)
+ return err;
+ }
+ } else {
+ kmsg->msg_name = NULL;
+ kmsg->msg_namelen = 0;
+ }
+
+ if (kmsg->msg_iovlen > UIO_MAXIOV)
+ return -EMSGSIZE;
+
+ err = rw_copy_check_uvector(save_addr ? READ : WRITE,
+ uiov, kmsg->msg_iovlen,
+ UIO_FASTIOV, *iov, iov);
+ if (err >= 0)
+ kmsg->msg_iov = *iov;
+ return err;
}
static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
@@ -2020,26 +2054,17 @@ static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
__attribute__ ((aligned(sizeof(__kernel_size_t))));
/* 20 is size of ipv6_pktinfo */
unsigned char *ctl_buf = ctl;
- int err, ctl_len, total_len;
+ int ctl_len, total_len;
+ ssize_t err;
- err = -EFAULT;
- if (MSG_CMSG_COMPAT & flags) {
- if (get_compat_msghdr(msg_sys, msg_compat))
- return -EFAULT;
- } else {
- err = copy_msghdr_from_user(msg_sys, msg);
- if (err)
- return err;
- }
+ msg_sys->msg_name = &address;
- /* This will also move the address data into kernel space */
if (MSG_CMSG_COMPAT & flags)
- err = verify_compat_iovec(msg_sys, iovstack, &address, WRITE);
+ err = get_compat_msghdr(msg_sys, msg_compat, NULL, &iov);
else
- err = verify_iovec(msg_sys, iovstack, &address, WRITE);
+ err = copy_msghdr_from_user(msg_sys, msg, NULL, &iov);
if (err < 0)
goto out_freeiov;
- iov = msg_sys->msg_iov;
total_len = err;
err = -ENOBUFS;
@@ -2215,36 +2240,24 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
struct iovec iovstack[UIO_FASTIOV];
struct iovec *iov = iovstack;
unsigned long cmsg_ptr;
- int err, total_len, len;
+ int total_len, len;
+ ssize_t err;
/* kernel mode address */
struct sockaddr_storage addr;
/* user mode address pointers */
struct sockaddr __user *uaddr;
- int __user *uaddr_len;
+ int __user *uaddr_len = COMPAT_NAMELEN(msg);
- if (MSG_CMSG_COMPAT & flags) {
- if (get_compat_msghdr(msg_sys, msg_compat))
- return -EFAULT;
- } else {
- err = copy_msghdr_from_user(msg_sys, msg);
- if (err)
- return err;
- }
+ msg_sys->msg_name = &addr;
- /* Save the user-mode address (verify_iovec will change the
- * kernel msghdr to use the kernel address space)
- */
- uaddr = (__force void __user *)msg_sys->msg_name;
- uaddr_len = COMPAT_NAMELEN(msg);
if (MSG_CMSG_COMPAT & flags)
- err = verify_compat_iovec(msg_sys, iovstack, &addr, READ);
+ err = get_compat_msghdr(msg_sys, msg_compat, &uaddr, &iov);
else
- err = verify_iovec(msg_sys, iovstack, &addr, READ);
+ err = copy_msghdr_from_user(msg_sys, msg, &uaddr, &iov);
if (err < 0)
goto out_freeiov;
- iov = msg_sys->msg_iov;
total_len = err;
cmsg_ptr = (unsigned long)msg_sys->msg_control;
--
1.7.10.4
--
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