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authorLinus Torvalds2020-08-04 14:11:08 -0700
committerLinus Torvalds2020-08-04 14:11:08 -0700
commit9ecc6ea491f0c0531ad81ef9466284df260b2227 (patch)
treeb6517635ca43d7eccb6c189c15be966cdb6bbf4f /net
parent99ea1521a097db51f0f04f54cfbd3b0ed119d2f1 (diff)
parentc97aedc52dce4c87d4c44de4e6af941cd102600c (diff)
Merge tag 'seccomp-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull seccomp updates from Kees Cook: "There are a bunch of clean ups and selftest improvements along with two major updates to the SECCOMP_RET_USER_NOTIF filter return: EPOLLHUP support to more easily detect the death of a monitored process, and being able to inject fds when intercepting syscalls that expect an fd-opening side-effect (needed by both container folks and Chrome). The latter continued the refactoring of __scm_install_fd() started by Christoph, and in the process found and fixed a handful of bugs in various callers. - Improved selftest coverage, timeouts, and reporting - Add EPOLLHUP support for SECCOMP_RET_USER_NOTIF (Christian Brauner) - Refactor __scm_install_fd() into __receive_fd() and fix buggy callers - Introduce 'addfd' command for SECCOMP_RET_USER_NOTIF (Sargun Dhillon)" * tag 'seccomp-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (30 commits) selftests/seccomp: Test SECCOMP_IOCTL_NOTIF_ADDFD seccomp: Introduce addfd ioctl to seccomp user notifier fs: Expand __receive_fd() to accept existing fd pidfd: Replace open-coded receive_fd() fs: Add receive_fd() wrapper for __receive_fd() fs: Move __scm_install_fd() to __receive_fd() net/scm: Regularize compat handling of scm_detach_fds() pidfd: Add missing sock updates for pidfd_getfd() net/compat: Add missing sock updates for SCM_RIGHTS selftests/seccomp: Check ENOSYS under tracing selftests/seccomp: Refactor to use fixture variants selftests/harness: Clean up kern-doc for fixtures seccomp: Use -1 marker for end of mode 1 syscall list seccomp: Fix ioctl number for SECCOMP_IOCTL_NOTIF_ID_VALID selftests/seccomp: Rename user_trap_syscall() to user_notif_syscall() selftests/seccomp: Make kcmp() less required seccomp: Use pr_fmt selftests/seccomp: Improve calibration loop selftests/seccomp: use 90s as timeout selftests/seccomp: Expand benchmark to per-filter measurements ...
Diffstat (limited to 'net')
-rw-r--r--net/compat.c55
-rw-r--r--net/core/scm.c50
-rw-r--r--net/core/sock.c21
3 files changed, 56 insertions, 70 deletions
diff --git a/net/compat.c b/net/compat.c
index 434838bef5f8..77f3a0e98fd0 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -281,39 +281,31 @@ int put_cmsg_compat(struct msghdr *kmsg, int level, int type, int len, void *dat
return 0;
}
-void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm)
+static int scm_max_fds_compat(struct msghdr *msg)
{
- struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control;
- int fdmax = (kmsg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int);
- int fdnum = scm->fp->count;
- struct file **fp = scm->fp->fp;
- int __user *cmfptr;
- int err = 0, i;
+ if (msg->msg_controllen <= sizeof(struct compat_cmsghdr))
+ return 0;
+ return (msg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int);
+}
- if (fdnum < fdmax)
- fdmax = fdnum;
+void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm)
+{
+ struct compat_cmsghdr __user *cm =
+ (struct compat_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_compat(msg), scm->fp->count);
+ int __user *cmsg_data = CMSG_USER_DATA(cm);
+ int err = 0, i;
- for (i = 0, cmfptr = (int __user *) CMSG_COMPAT_DATA(cm); i < fdmax; i++, cmfptr++) {
- int new_fd;
- err = security_file_receive(fp[i]);
- if (err)
- break;
- err = get_unused_fd_flags(MSG_CMSG_CLOEXEC & kmsg->msg_flags
- ? O_CLOEXEC : 0);
+ for (i = 0; i < fdmax; i++) {
+ err = receive_fd_user(scm->fp->fp[i], cmsg_data + i, o_flags);
if (err < 0)
break;
- new_fd = err;
- err = put_user(new_fd, cmfptr);
- if (err) {
- put_unused_fd(new_fd);
- break;
- }
- /* Bump the usage count and install the file. */
- fd_install(new_fd, get_file(fp[i]));
}
if (i > 0) {
int cmlen = CMSG_COMPAT_LEN(i * sizeof(int));
+
err = put_user(SOL_SOCKET, &cm->cmsg_level);
if (!err)
err = put_user(SCM_RIGHTS, &cm->cmsg_type);
@@ -321,16 +313,19 @@ void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm)
err = put_user(cmlen, &cm->cmsg_len);
if (!err) {
cmlen = CMSG_COMPAT_SPACE(i * sizeof(int));
- kmsg->msg_control += cmlen;
- kmsg->msg_controllen -= cmlen;
+ if (msg->msg_controllen < cmlen)
+ cmlen = msg->msg_controllen;
+ msg->msg_control += cmlen;
+ msg->msg_controllen -= cmlen;
}
}
- if (i < fdnum)
- kmsg->msg_flags |= MSG_CTRUNC;
+
+ if (i < scm->fp->count || (scm->fp->count && fdmax <= 0))
+ msg->msg_flags |= MSG_CTRUNC;
/*
- * All of the files that fit in the message have had their
- * usage counts incremented, so we just free the list.
+ * All of the files that fit in the message have had their usage counts
+ * incremented, so we just free the list.
*/
__scm_destroy(scm);
}
diff --git a/net/core/scm.c b/net/core/scm.c
index 875df1c2989d..8156d4fb8a39 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -280,36 +280,6 @@ 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)
-{
- struct socket *sock;
- int new_fd;
- int error;
-
- error = security_file_receive(file);
- if (error)
- return error;
-
- new_fd = get_unused_fd_flags(o_flags);
- if (new_fd < 0)
- return new_fd;
-
- error = put_user(new_fd, ufd);
- if (error) {
- put_unused_fd(new_fd);
- 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);
- }
- fd_install(new_fd, get_file(file));
- return 0;
-}
-
static int scm_max_fds(struct msghdr *msg)
{
if (msg->msg_controllen <= sizeof(struct cmsghdr))
@@ -319,29 +289,29 @@ 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)
+ err = receive_fd_user(scm->fp->fp[i], cmsg_data + i, o_flags);
+ if (err < 0)
break;
}
- if (i > 0) {
+ if (i > 0) {
int cmlen = CMSG_LEN(i * sizeof(int));
err = put_user(SOL_SOCKET, &cm->cmsg_level);
diff --git a/net/core/sock.c b/net/core/sock.c
index b8ac834f5386..8ccdcdaaa673 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2842,6 +2842,27 @@ 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;