diff options
author | Kees Cook <keescook@chromium.org> | 2020-06-09 16:11:29 -0700 |
---|---|---|
committer | Kees Cook <keescook@chromium.org> | 2020-07-13 11:03:44 -0700 |
commit | c0029de50982c1fb215330a5f9d433cec0cfd8cc (patch) | |
tree | 3452e01c860c87aa389cb5f4f5f95f629173fd00 /net/core/scm.c | |
parent | 4969f8a073977123504609d7310b42a588297aa4 (diff) | |
download | linux-c0029de50982c1fb215330a5f9d433cec0cfd8cc.tar.bz2 |
net/scm: Regularize compat handling of scm_detach_fds()
Duplicate the cleanups from commit 2618d530dd8b ("net/scm: cleanup
scm_detach_fds") into the compat code.
Replace open-coded __receive_sock() with a call to the helper.
Move the check added in commit 1f466e1f15cf ("net: cleanly handle kernel
vs user buffers for ->msg_control") to before the compat call, even
though it should be impossible for an in-kernel call to also be compat.
Correct the int "flags" argument to unsigned int to match fd_install()
and similar APIs.
Regularize any remaining differences, including a whitespace issue,
a checkpatch warning, and add the check from commit 6900317f5eff ("net,
scm: fix PaX detected msg_controllen overflow in scm_detach_fds") which
fixed an overflow unique to 64-bit. To avoid confusion when comparing
the compat handler to the native handler, just include the same check
in the compat handler.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sargun Dhillon <sargun@sargun.me>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'net/core/scm.c')
-rw-r--r-- | net/core/scm.c | 27 |
1 files changed, 11 insertions, 16 deletions
diff --git a/net/core/scm.c b/net/core/scm.c index 875df1c2989d..44f03213dcab 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -280,9 +280,8 @@ void put_cmsg_scm_timestamping(struct msghdr *msg, struct scm_timestamping_inter } EXPORT_SYMBOL(put_cmsg_scm_timestamping); -static int __scm_install_fd(struct file *file, int __user *ufd, int o_flags) +int __scm_install_fd(struct file *file, int __user *ufd, unsigned int o_flags) { - struct socket *sock; int new_fd; int error; @@ -300,12 +299,8 @@ static int __scm_install_fd(struct file *file, int __user *ufd, int o_flags) return error; } - /* Bump the usage count and install the file. */ - sock = sock_from_file(file, &error); - if (sock) { - sock_update_netprioidx(&sock->sk->sk_cgrp_data); - sock_update_classid(&sock->sk->sk_cgrp_data); - } + /* Bump the sock usage counts, if any. */ + __receive_sock(file); fd_install(new_fd, get_file(file)); return 0; } @@ -319,29 +314,29 @@ static int scm_max_fds(struct msghdr *msg) void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm) { - struct cmsghdr __user *cm - = (__force struct cmsghdr __user*)msg->msg_control; - int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0; + struct cmsghdr __user *cm = + (__force struct cmsghdr __user *)msg->msg_control; + unsigned int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0; int fdmax = min_t(int, scm_max_fds(msg), scm->fp->count); int __user *cmsg_data = CMSG_USER_DATA(cm); int err = 0, i; + /* no use for FD passing from kernel space callers */ + if (WARN_ON_ONCE(!msg->msg_control_is_user)) + return; + if (msg->msg_flags & MSG_CMSG_COMPAT) { scm_detach_fds_compat(msg, scm); return; } - /* no use for FD passing from kernel space callers */ - if (WARN_ON_ONCE(!msg->msg_control_is_user)) - return; - for (i = 0; i < fdmax; i++) { err = __scm_install_fd(scm->fp->fp[i], cmsg_data + i, o_flags); if (err) break; } - if (i > 0) { + if (i > 0) { int cmlen = CMSG_LEN(i * sizeof(int)); err = put_user(SOL_SOCKET, &cm->cmsg_level); |