diff --git a/fs/file.c b/fs/file.c index f3a4bac2cbe9..d8ccb95a7f41 100644 --- a/fs/file.c +++ b/fs/file.c @@ -1068,8 +1068,6 @@ int replace_fd(unsigned fd, struct file *file, unsigned flags) /** * __receive_fd() - Install received file into file descriptor table - * - * @fd: fd to install into (if negative, a new fd will be allocated) * @file: struct file that was received from another process * @ufd: __user pointer to write new fd number to * @o_flags: the O_* flags to apply to the new fd entry @@ -1083,7 +1081,7 @@ int replace_fd(unsigned fd, struct file *file, unsigned flags) * * Returns newly install fd or -ve on error. */ -int __receive_fd(int fd, struct file *file, int __user *ufd, unsigned int o_flags) +int __receive_fd(struct file *file, int __user *ufd, unsigned int o_flags) { int new_fd; int error; @@ -1092,32 +1090,33 @@ int __receive_fd(int fd, struct file *file, int __user *ufd, unsigned int o_flag if (error) return error; - if (fd < 0) { - new_fd = get_unused_fd_flags(o_flags); - if (new_fd < 0) - return new_fd; - } else { - new_fd = fd; - } + new_fd = get_unused_fd_flags(o_flags); + if (new_fd < 0) + return new_fd; if (ufd) { error = put_user(new_fd, ufd); if (error) { - if (fd < 0) - put_unused_fd(new_fd); + put_unused_fd(new_fd); return error; } } - if (fd < 0) { - fd_install(new_fd, get_file(file)); - } else { - error = replace_fd(new_fd, file, o_flags); - if (error) - return error; - } + fd_install(new_fd, get_file(file)); + __receive_sock(file); + return new_fd; +} - /* Bump the sock usage counts, if any. */ +int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags) +{ + int error; + + error = security_file_receive(file); + if (error) + return error; + error = replace_fd(new_fd, file, o_flags); + if (error) + return error; __receive_sock(file); return new_fd; } diff --git a/include/linux/file.h b/include/linux/file.h index 225982792fa2..2de2e4613d7b 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -92,23 +92,20 @@ extern void put_unused_fd(unsigned int fd); extern void fd_install(unsigned int fd, struct file *file); -extern int __receive_fd(int fd, struct file *file, int __user *ufd, +extern int __receive_fd(struct file *file, int __user *ufd, unsigned int o_flags); static inline int receive_fd_user(struct file *file, int __user *ufd, unsigned int o_flags) { if (ufd == NULL) return -EFAULT; - return __receive_fd(-1, file, ufd, o_flags); + return __receive_fd(file, ufd, o_flags); } static inline int receive_fd(struct file *file, unsigned int o_flags) { - return __receive_fd(-1, file, NULL, o_flags); -} -static inline int receive_fd_replace(int fd, struct file *file, unsigned int o_flags) -{ - return __receive_fd(fd, file, NULL, o_flags); + return __receive_fd(file, NULL, o_flags); } +int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags); extern void flush_delayed_fput(void); extern void __fput_sync(struct file *); diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 1d60fc2c9987..4fe19cecaa94 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -119,8 +119,11 @@ struct seccomp_kaddfd { int fd; unsigned int flags; - /* To only be set on reply */ - int ret; + union { + bool setfd; + /* To only be set on reply */ + int ret; + }; struct completion completion; struct list_head list; }; @@ -1069,7 +1072,11 @@ static void seccomp_handle_addfd(struct seccomp_kaddfd *addfd) * that it has been handled. */ list_del_init(&addfd->list); - addfd->ret = receive_fd_replace(addfd->fd, addfd->file, addfd->flags); + if (!addfd->setfd) + addfd->ret = receive_fd(addfd->file, addfd->flags); + else + addfd->ret = receive_fd_replace(addfd->fd, addfd->file, + addfd->flags); complete(&addfd->completion); } @@ -1583,8 +1590,8 @@ static long seccomp_notify_addfd(struct seccomp_filter *filter, return -EBADF; kaddfd.flags = addfd.newfd_flags; - kaddfd.fd = (addfd.flags & SECCOMP_ADDFD_FLAG_SETFD) ? - addfd.newfd : -1; + kaddfd.setfd = addfd.flags & SECCOMP_ADDFD_FLAG_SETFD; + kaddfd.fd = addfd.newfd; init_completion(&kaddfd.completion); ret = mutex_lock_interruptible(&filter->notify_lock);