diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h index 5ef57f88df6b..946a5fad2691 100644 --- a/arch/alpha/include/uapi/asm/socket.h +++ b/arch/alpha/include/uapi/asm/socket.h @@ -155,6 +155,8 @@ #define SO_INQ 84 #define SCM_INQ SO_INQ +#define SO_RIGHTS_NOTRUNC 85 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h index 72fb1b006da9..f1641dde135f 100644 --- a/arch/mips/include/uapi/asm/socket.h +++ b/arch/mips/include/uapi/asm/socket.h @@ -166,6 +166,8 @@ #define SO_INQ 84 #define SCM_INQ SO_INQ +#define SO_RIGHTS_NOTRUNC 85 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h index c16ec36dfee6..f3a3815c7dc2 100644 --- a/arch/parisc/include/uapi/asm/socket.h +++ b/arch/parisc/include/uapi/asm/socket.h @@ -147,6 +147,8 @@ #define SO_INQ 0x4052 #define SCM_INQ SO_INQ +#define SO_RIGHTS_NOTRUNC 0x4053 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h index 71befa109e1c..7907f3b1f0ee 100644 --- a/arch/sparc/include/uapi/asm/socket.h +++ b/arch/sparc/include/uapi/asm/socket.h @@ -148,6 +148,8 @@ #define SO_INQ 0x005d #define SCM_INQ SO_INQ +#define SO_RIGHTS_NOTRUNC 0x005e + #if !defined(__KERNEL__) diff --git a/include/net/af_unix.h b/include/net/af_unix.h index 34f53dde65ce..bb1b3dee02e8 100644 --- a/include/net/af_unix.h +++ b/include/net/af_unix.h @@ -49,6 +49,7 @@ struct unix_sock { struct scm_stat scm_stat; int inq_len; bool recvmsg_inq; + bool scm_rights_notrunc; #if IS_ENABLED(CONFIG_AF_UNIX_OOB) struct sk_buff *oob_skb; #endif diff --git a/include/net/scm.h b/include/net/scm.h index c52519669349..86ae6bc109ec 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -50,8 +50,8 @@ struct scm_cookie { #endif }; -void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm); -void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm); +void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm, bool notrunc); +void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm, bool notrunc); int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm); void __scm_destroy(struct scm_cookie *scm); struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl); @@ -107,13 +107,8 @@ void scm_recv(struct socket *sock, struct msghdr *msg, void scm_recv_unix(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm, int flags); -static inline int scm_recv_one_fd(struct file *f, int __user *ufd, - unsigned int flags) -{ - if (!ufd) - return -EFAULT; - return receive_fd(f, ufd, flags); -} +int scm_recv_one_fd(struct file *f, int __user *ufd, unsigned int flags, + bool notrunc); #endif /* __LINUX_NET_SCM_H */ diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h index 53b5a8c002b1..84ea7b92936e 100644 --- a/include/uapi/asm-generic/socket.h +++ b/include/uapi/asm-generic/socket.h @@ -150,6 +150,8 @@ #define SO_INQ 84 #define SCM_INQ SO_INQ +#define SO_RIGHTS_NOTRUNC 85 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__)) diff --git a/net/compat.c b/net/compat.c index d68cf9c3aad5..6bdf4a2c9077 100644 --- a/net/compat.c +++ b/net/compat.c @@ -286,7 +286,7 @@ static int scm_max_fds_compat(struct msghdr *msg) return (msg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int); } -void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm) +void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm, bool notrunc) { struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *)msg->msg_control_user; @@ -296,7 +296,7 @@ void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm) int err = 0, i; for (i = 0; i < fdmax; i++) { - err = scm_recv_one_fd(scm->fp->fp[i], cmsg_data + i, o_flags); + err = scm_recv_one_fd(scm->fp->fp[i], cmsg_data + i, o_flags, notrunc); if (err < 0) break; } diff --git a/net/core/scm.c b/net/core/scm.c index a73b1eb30fd2..f0d44ecdb11f 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -351,7 +351,31 @@ static int scm_max_fds(struct msghdr *msg) return (msg->msg_controllen - sizeof(struct cmsghdr)) / sizeof(int); } -void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm) +int scm_recv_one_fd(struct file *f, int __user *ufd, unsigned int flags, + bool notrunc) +{ + int error; + + if (!ufd) + return -EFAULT; + + error = security_file_receive(f); + if (error) + return notrunc ? put_user(error, ufd) : error; + + FD_PREPARE(fdf, flags, get_file(f)); + if (fdf.err) + return fdf.err; + + error = put_user(fd_prepare_fd(fdf), ufd); + if (error) + return error; + + __receive_sock(fd_prepare_file(fdf)); + return fd_publish(fdf); +} + +void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm, bool notrunc) { struct cmsghdr __user *cm = (__force struct cmsghdr __user *)msg->msg_control_user; @@ -365,12 +389,12 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm) return; if (msg->msg_flags & MSG_CMSG_COMPAT) { - scm_detach_fds_compat(msg, scm); + scm_detach_fds_compat(msg, scm, notrunc); return; } for (i = 0; i < fdmax; i++) { - err = scm_recv_one_fd(scm->fp->fp[i], cmsg_data + i, o_flags); + err = scm_recv_one_fd(scm->fp->fp[i], cmsg_data + i, o_flags, notrunc); if (err < 0) break; } @@ -542,8 +566,12 @@ void scm_recv_unix(struct socket *sock, struct msghdr *msg, if (!__scm_recv_common(sock->sk, msg, scm, flags)) return; - if (scm->fp) - scm_detach_fds(msg, scm); + if (scm->fp) { + struct unix_sock *u; + + u = unix_sk(sock->sk); + scm_detach_fds(msg, scm, READ_ONCE(u->scm_rights_notrunc)); + } if (sock->sk->sk_scm_pidfd) scm_pidfd_recv(msg, scm); diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 51cbf920130d..5c0549e6784f 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -922,6 +922,7 @@ static bool unix_custom_sockopt(int optname) { switch (optname) { case SO_INQ: + case SO_RIGHTS_NOTRUNC: return true; default: return false; @@ -957,6 +958,14 @@ static int unix_setsockopt(struct socket *sock, int level, int optname, WRITE_ONCE(u->recvmsg_inq, val); break; + + case SO_RIGHTS_NOTRUNC: + if (val > 1 || val < 0) + return -EINVAL; + + WRITE_ONCE(u->scm_rights_notrunc, val); + break; + default: return -ENOPROTOOPT; } @@ -1746,9 +1755,10 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr_unsized *uad init_peercred(newsk, &peercred); newu = unix_sk(newsk); - newu->listener = other; - RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq); otheru = unix_sk(other); + newu->listener = other; + newu->scm_rights_notrunc = READ_ONCE(otheru->scm_rights_notrunc); + RCU_INIT_POINTER(newsk->sk_wq, &newu->peer_wq); /* copy address information from listening to new sock *