The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From d9539752d23283db4692384a634034f451261e29 Mon Sep 17 00:00:00 2001
From: Kees Cook keescook@chromium.org Date: Tue, 9 Jun 2020 16:11:29 -0700 Subject: [PATCH] net/compat: Add missing sock updates for SCM_RIGHTS
Add missed sock updates to compat path via a new helper, which will be used more in coming patches. (The net/core/scm.c code is left as-is here to assist with -stable backports for the compat path.)
Cc: Christoph Hellwig hch@lst.de Cc: Sargun Dhillon sargun@sargun.me Cc: Jakub Kicinski kuba@kernel.org Cc: stable@vger.kernel.org Fixes: 48a87cc26c13 ("net: netprio: fd passed in SCM_RIGHTS datagram not set correctly") Fixes: d84295067fc7 ("net: net_cls: fd passed in SCM_RIGHTS datagram not set correctly") Acked-by: Christian Brauner christian.brauner@ubuntu.com Signed-off-by: Kees Cook keescook@chromium.org
diff --git a/include/net/sock.h b/include/net/sock.h index c53cc42b5ab9..2be67f1ee8b1 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -890,6 +890,8 @@ static inline int sk_memalloc_socks(void) { return static_branch_unlikely(&memalloc_socks_key); } + +void __receive_sock(struct file *file); #else
static inline int sk_memalloc_socks(void) @@ -897,6 +899,8 @@ static inline int sk_memalloc_socks(void) return 0; }
+static inline void __receive_sock(struct file *file) +{ } #endif
static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask) diff --git a/net/compat.c b/net/compat.c index 5e3041a2c37d..2937b816107d 100644 --- a/net/compat.c +++ b/net/compat.c @@ -309,6 +309,7 @@ void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm) break; } /* Bump the usage count and install the file. */ + __receive_sock(fp[i]); fd_install(new_fd, get_file(fp[i])); }
diff --git a/net/core/sock.c b/net/core/sock.c index 6c4acf1f0220..bde394979041 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2840,6 +2840,27 @@ int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct * } EXPORT_SYMBOL(sock_no_mmap);
+/* + * When a file is received (via SCM_RIGHTS, etc), we must bump the + * various sock-based usage counts. + */ +void __receive_sock(struct file *file) +{ + struct socket *sock; + int error; + + /* + * The resulting value of "error" is ignored here since we only + * need to take action when the file is a socket and testing + * "sock" for NULL is sufficient. + */ + sock = sock_from_file(file, &error); + if (sock) { + sock_update_netprioidx(&sock->sk->sk_cgrp_data); + sock_update_classid(&sock->sk->sk_cgrp_data); + } +} + ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags) { ssize_t res;