1 files changed, 106 insertions, 86 deletions

diff --git a/net/socket.c b/net/socket.c
index 74283610db15..510ae18d220a 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -426,6 +426,28 @@ int sock_map_fd(struct socket *sock)
         return fd;
 }
 
+static struct socket *sock_from_file(struct file *file, int *err)
+{
+        struct inode *inode;
+        struct socket *sock;
+
+        if (file->f_op == &socket_file_ops)
+                return file->private_data;      /* set in sock_map_fd */
+
+        inode = file->f_dentry->d_inode;
+        if (!S_ISSOCK(inode->i_mode)) {
+                *err = -ENOTSOCK;
+                return NULL;
+        }
+
+        sock = SOCKET_I(inode);
+        if (sock->file != file) {
+                printk(KERN_ERR "socki_lookup: socket file changed!\n");
+                sock->file = file;
+        }
+        return sock;
+}
+
 /**
  *      sockfd_lookup   -       Go from a file number to its socket slot
  *      @fd: file handle
@@ -442,31 +464,31 @@ int sock_map_fd(struct socket *sock)
 struct socket *sockfd_lookup(int fd, int *err)
 {
         struct file *file;
-        struct inode *inode;
         struct socket *sock;
 
-        if (!(file = fget(fd)))
-        {
+        if (!(file = fget(fd))) {
                 *err = -EBADF;
                 return NULL;
         }
-
-        if (file->f_op == &socket_file_ops)
-                return file->private_data;      /* set in sock_map_fd */
-
-        inode = file->f_dentry->d_inode;
-        if (!S_ISSOCK(inode->i_mode)) {
-                *err = -ENOTSOCK;
+        sock = sock_from_file(file, err);
+        if (!sock)
                 fput(file);
-                return NULL;
-        }
+        return sock;
+}
 
-        sock = SOCKET_I(inode);
-        if (sock->file != file) {
-                printk(KERN_ERR "socki_lookup: socket file changed!\n");
-                sock->file = file;
+static struct socket *sockfd_lookup_light(int fd, int *err, int *fput_needed)
+{
+        struct file *file;
+        struct socket *sock;
+
+        file = fget_light(fd, fput_needed);
+        if (file) {
+                sock = sock_from_file(file, err);
+                if (sock)
+                        return sock;
+                fput_light(file, *fput_needed);
         }
-        return sock;
+        return NULL;
 }
 
 /**
@@ -1301,19 +1323,17 @@ asmlinkage long sys_bind(int fd, struct sockaddr __user *umyaddr, int addrlen)
 {
         struct socket *sock;
         char address[MAX_SOCK_ADDR];
-        int err;
+        int err, fput_needed;
 
-        if((sock = sockfd_lookup(fd,&err))!=NULL)
+        if((sock = sockfd_lookup_light(fd, &err, &fput_needed))!=NULL)
         {
                 if((err=move_addr_to_kernel(umyaddr,addrlen,address))>=0) {
                         err = security_socket_bind(sock, (struct sockaddr *)address, addrlen);
-                        if (err) {
-                                sockfd_put(sock);
-                                return err;
-                        }
-                        err = sock->ops->bind(sock, (struct sockaddr *)address, addrlen);
+                        if (!err)
+                                err = sock->ops->bind(sock,
+                                        (struct sockaddr *)address, addrlen);
                 }
-                sockfd_put(sock);
+                fput_light(sock->file, fput_needed);
         }                       
         return err;
 }
@@ -1330,20 +1350,17 @@ int sysctl_somaxconn = SOMAXCONN;
 asmlinkage long sys_listen(int fd, int backlog)
 {
         struct socket *sock;
-        int err;
+        int err, fput_needed;
         
-        if ((sock = sockfd_lookup(fd, &err)) != NULL) {
+        if ((sock = sockfd_lookup_light(fd, &err, &fput_needed)) != NULL) {
                 if ((unsigned) backlog > sysctl_somaxconn)
                         backlog = sysctl_somaxconn;
 
                 err = security_socket_listen(sock, backlog);
-                if (err) {
-                        sockfd_put(sock);
-                        return err;
-                }
+                if (!err)
+                        err = sock->ops->listen(sock, backlog);
 
-                err=sock->ops->listen(sock, backlog);
-                sockfd_put(sock);
+                fput_light(sock->file, fput_needed);
         }
         return err;
 }
@@ -1365,10 +1382,10 @@ asmlinkage long sys_accept(int fd, struct sockaddr __user *upeer_sockaddr, int _
 {
         struct socket *sock, *newsock;
         struct file *newfile;
-        int err, len, newfd;
+        int err, len, newfd, fput_needed;
         char address[MAX_SOCK_ADDR];
 
-        sock = sockfd_lookup(fd, &err);
+        sock = sockfd_lookup_light(fd, &err, &fput_needed);
         if (!sock)
                 goto out;
 
@@ -1421,7 +1438,7 @@ asmlinkage long sys_accept(int fd, struct sockaddr __user *upeer_sockaddr, int _
         security_socket_post_accept(sock, newsock);
 
 out_put:
-        sockfd_put(sock);
+        fput_light(sock->file, fput_needed);
 out:
         return err;
 out_fd:
@@ -1449,9 +1466,9 @@ asmlinkage long sys_connect(int fd, struct sockaddr __user *uservaddr, int addrl
 {
         struct socket *sock;
         char address[MAX_SOCK_ADDR];
-        int err;
+        int err, fput_needed;
 
-        sock = sockfd_lookup(fd, &err);
+        sock = sockfd_lookup_light(fd, &err, &fput_needed);
         if (!sock)
                 goto out;
         err = move_addr_to_kernel(uservaddr, addrlen, address);
@@ -1465,7 +1482,7 @@ asmlinkage long sys_connect(int fd, struct sockaddr __user *uservaddr, int addrl
         err = sock->ops->connect(sock, (struct sockaddr *) address, addrlen,
                                  sock->file->f_flags);
 out_put:
-        sockfd_put(sock);
+        fput_light(sock->file, fput_needed);
 out:
         return err;
 }
@@ -1479,9 +1496,9 @@ asmlinkage long sys_getsockname(int fd, struct sockaddr __user *usockaddr, int _
 {
         struct socket *sock;
         char address[MAX_SOCK_ADDR];
-        int len, err;
+        int len, err, fput_needed;
         
-        sock = sockfd_lookup(fd, &err);
+        sock = sockfd_lookup_light(fd, &err, &fput_needed);
         if (!sock)
                 goto out;
 
@@ -1495,7 +1512,7 @@ asmlinkage long sys_getsockname(int fd, struct sockaddr __user *usockaddr, int _
         err = move_addr_to_user(address, len, usockaddr, usockaddr_len);
 
 out_put:
-        sockfd_put(sock);
+        fput_light(sock->file, fput_needed);
 out:
         return err;
 }
@@ -1509,20 +1526,19 @@ asmlinkage long sys_getpeername(int fd, struct sockaddr __user *usockaddr, int _
 {
         struct socket *sock;
         char address[MAX_SOCK_ADDR];
-        int len, err;
+        int len, err, fput_needed;
 
-        if ((sock = sockfd_lookup(fd, &err))!=NULL)
-        {
+        if ((sock = sockfd_lookup_light(fd, &err, &fput_needed)) != NULL) {
                 err = security_socket_getpeername(sock);
                 if (err) {
-                        sockfd_put(sock);
+                        fput_light(sock->file, fput_needed);
                         return err;
                 }
 
                 err = sock->ops->getname(sock, (struct sockaddr *)address, &len, 1);
                 if (!err)
                         err=move_addr_to_user(address,len, usockaddr, usockaddr_len);
-                sockfd_put(sock);
+                fput_light(sock->file, fput_needed);
         }
         return err;
 }
@@ -1541,10 +1557,16 @@ asmlinkage long sys_sendto(int fd, void __user * buff, size_t len, unsigned flag
         int err;
         struct msghdr msg;
         struct iovec iov;
-        
-        sock = sockfd_lookup(fd, &err);
+        int fput_needed;
+        struct file *sock_file;
+
+        sock_file = fget_light(fd, &fput_needed);
+        if (!sock_file)
+                return -EBADF;
+
+        sock = sock_from_file(sock_file, &err);
         if (!sock)
-                goto out;
+                goto out_put;
         iov.iov_base=buff;
         iov.iov_len=len;
         msg.msg_name=NULL;
@@ -1553,8 +1575,7 @@ asmlinkage long sys_sendto(int fd, void __user * buff, size_t len, unsigned flag
         msg.msg_control=NULL;
         msg.msg_controllen=0;
         msg.msg_namelen=0;
-        if(addr)
-        {
+        if (addr) {
                 err = move_addr_to_kernel(addr, addr_len, address);
                 if (err < 0)
                         goto out_put;
@@ -1567,8 +1588,7 @@ asmlinkage long sys_sendto(int fd, void __user * buff, size_t len, unsigned flag
         err = sock_sendmsg(sock, &msg, len);
 
 out_put:                
-        sockfd_put(sock);
-out:
+        fput_light(sock_file, fput_needed);
         return err;
 }
 
@@ -1595,8 +1615,14 @@ asmlinkage long sys_recvfrom(int fd, void __user * ubuf, size_t size, unsigned f
         struct msghdr msg;
         char address[MAX_SOCK_ADDR];
         int err,err2;
+        struct file *sock_file;
+        int fput_needed;
+
+        sock_file = fget_light(fd, &fput_needed);
+        if (!sock_file)
+                return -EBADF;
 
-        sock = sockfd_lookup(fd, &err);
+        sock = sock_from_file(sock_file, &err);
         if (!sock)
                 goto out;
 
@@ -1618,8 +1644,8 @@ asmlinkage long sys_recvfrom(int fd, void __user * ubuf, size_t size, unsigned f
                 if(err2<0)
                         err=err2;
         }
-        sockfd_put(sock);                       
 out:
+        fput_light(sock_file, fput_needed);
         return err;
 }
 
@@ -1639,25 +1665,24 @@ asmlinkage long sys_recv(int fd, void __user * ubuf, size_t size, unsigned flags
 
 asmlinkage long sys_setsockopt(int fd, int level, int optname, char __user *optval, int optlen)
 {
-        int err;
+        int err, fput_needed;
         struct socket *sock;
 
         if (optlen < 0)
                 return -EINVAL;
                         
-        if ((sock = sockfd_lookup(fd, &err))!=NULL)
+        if ((sock = sockfd_lookup_light(fd, &err, &fput_needed)) != NULL)
         {
                 err = security_socket_setsockopt(sock,level,optname);
-                if (err) {
-                        sockfd_put(sock);
-                        return err;
-                }
+                if (err)
+                        goto out_put;
 
                 if (level == SOL_SOCKET)
                         err=sock_setsockopt(sock,level,optname,optval,optlen);
                 else
                         err=sock->ops->setsockopt(sock, level, optname, optval, optlen);
-                sockfd_put(sock);
+out_put:
+                fput_light(sock->file, fput_needed);
         }
         return err;
 }
@@ -1669,23 +1694,20 @@ asmlinkage long sys_setsockopt(int fd, int level, int optname, char __user *optv
 
 asmlinkage long sys_getsockopt(int fd, int level, int optname, char __user *optval, int __user *optlen)
 {
-        int err;
+        int err, fput_needed;
         struct socket *sock;
 
-        if ((sock = sockfd_lookup(fd, &err))!=NULL)
-        {
-                err = security_socket_getsockopt(sock, level, 
-                                                           optname);
-                if (err) {
-                        sockfd_put(sock);
-                        return err;
-                }
+        if ((sock = sockfd_lookup_light(fd, &err, &fput_needed)) != NULL) {
+                err = security_socket_getsockopt(sock, level, optname);
+                if (err)
+                        goto out_put;
 
                 if (level == SOL_SOCKET)
                         err=sock_getsockopt(sock,level,optname,optval,optlen);
                 else
                         err=sock->ops->getsockopt(sock, level, optname, optval, optlen);
-                sockfd_put(sock);
+out_put:
+                fput_light(sock->file, fput_needed);
         }
         return err;
 }
@@ -1697,19 +1719,15 @@ asmlinkage long sys_getsockopt(int fd, int level, int optname, char __user *optv
 
 asmlinkage long sys_shutdown(int fd, int how)
 {
-        int err;
+        int err, fput_needed;
         struct socket *sock;
 
-        if ((sock = sockfd_lookup(fd, &err))!=NULL)
+        if ((sock = sockfd_lookup_light(fd, &err, &fput_needed))!=NULL)
         {
                 err = security_socket_shutdown(sock, how);
-                if (err) {
-                        sockfd_put(sock);
-                        return err;
-                }
-                                
-                err=sock->ops->shutdown(sock, how);
-                sockfd_put(sock);
+                if (!err)
+                        err = sock->ops->shutdown(sock, how);
+                fput_light(sock->file, fput_needed);
         }
         return err;
 }
@@ -1738,6 +1756,7 @@ asmlinkage long sys_sendmsg(int fd, struct msghdr __user *msg, unsigned flags)
         unsigned char *ctl_buf = ctl;
         struct msghdr msg_sys;
         int err, ctl_len, iov_size, total_len;
+        int fput_needed;
         
         err = -EFAULT;
         if (MSG_CMSG_COMPAT & flags) {
@@ -1746,7 +1765,7 @@ asmlinkage long sys_sendmsg(int fd, struct msghdr __user *msg, unsigned flags)
         } else if (copy_from_user(&msg_sys, msg, sizeof(struct msghdr)))
                 return -EFAULT;
 
-        sock = sockfd_lookup(fd, &err);
+        sock = sockfd_lookup_light(fd, &err, &fput_needed);
         if (!sock) 
                 goto out;
 
@@ -1814,7 +1833,7 @@ out_freeiov:
         if (iov != iovstack)
                 sock_kfree_s(sock->sk, iov, iov_size);
 out_put:
-        sockfd_put(sock);
+        fput_light(sock->file, fput_needed);
 out:       
         return err;
 }
@@ -1832,6 +1851,7 @@ asmlinkage long sys_recvmsg(int fd, struct msghdr __user *msg, unsigned int flag
         struct msghdr msg_sys;
         unsigned long cmsg_ptr;
         int err, iov_size, total_len, len;
+        int fput_needed;
 
         /* kernel mode address */
         char addr[MAX_SOCK_ADDR];
@@ -1847,7 +1867,7 @@ asmlinkage long sys_recvmsg(int fd, struct msghdr __user *msg, unsigned int flag
                 if (copy_from_user(&msg_sys,msg,sizeof(struct msghdr)))
                         return -EFAULT;
 
-        sock = sockfd_lookup(fd, &err);
+        sock = sockfd_lookup_light(fd, &err, &fput_needed);
         if (!sock)
                 goto out;
 
@@ -1914,7 +1934,7 @@ out_freeiov:
         if (iov != iovstack)
                 sock_kfree_s(sock->sk, iov, iov_size);
 out_put:
-        sockfd_put(sock);
+        fput_light(sock->file, fput_needed);
 out:
         return err;
 }