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fold verify_iovec() into copy_msghdr_from_user()
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... and do the same on the compat side of things.

Signed-off-by: Al Viro <[email protected]>
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Al Viro committed Nov 19, 2014
1 parent 0844932 commit 08adb7d
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Showing 5 changed files with 77 additions and 112 deletions.
1 change: 0 additions & 1 deletion include/linux/socket.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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);

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5 changes: 2 additions & 3 deletions include/net/compat.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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 *,
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52 changes: 22 additions & 30 deletions net/compat.c
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Original file line number Diff line number Diff line change
Expand Up @@ -31,59 +31,51 @@
#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) ||
__get_user(kmsg->msg_flags, &umsg->msg_flags))
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;
}

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38 changes: 0 additions & 38 deletions net/core/iovec.c
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Original file line number Diff line number Diff line change
Expand Up @@ -27,44 +27,6 @@
#include <net/checksum.h>
#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
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93 changes: 53 additions & 40 deletions net/socket.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1988,24 +1988,58 @@ 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)
return -EINVAL;

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,
Expand All @@ -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;
Expand Down Expand Up @@ -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;
Expand Down

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