log.h \
lxc.h \
lxclock.h \
+ macro.h \
monitor.h \
namespace.h \
+ rexec.h \
start.h \
state.h \
utils.h \
\
caps.c caps.h \
lxcseccomp.h \
+ macro.h \
mainloop.c mainloop.h \
af_unix.c af_unix.h \
\
endif
if ENFORCE_MEMFD_REXEC
-liblxc_la_SOURCES += rexec.c
+liblxc_la_SOURCES += rexec.c rexec.h
endif
AM_CFLAGS = -DLXCROOTFSMOUNT=\"$(LXCROOTFSMOUNT)\" \
endif
LDADD=liblxc.la @CAP_LIBS@ @SELINUX_LIBS@ @SECCOMP_LIBS@
-lxc_attach_SOURCES = tools/lxc_attach.c tools/arguments.c
+lxc_attach_SOURCES = tools/lxc_attach.c tools/arguments.c rexec.c rexec.h
lxc_autostart_SOURCES = tools/lxc_autostart.c tools/arguments.c
lxc_cgroup_SOURCES = tools/lxc_cgroup.c tools/arguments.c
lxc_config_SOURCES = tools/lxc_config.c tools/arguments.c
#include <unistd.h>
#include "lxccontainer.h"
+#include "macro.h"
#include "state.h"
-#define LXC_CMD_DATA_MAX (MAXPATHLEN * 2)
-
/* Length of abstract unix domain socket socket address. */
#define LXC_AUDS_ADDR_LEN sizeof(((struct sockaddr_un *)0)->sun_path)
#include <sys/types.h>
+#include "macro.h"
#include "utils.h"
-#define LXC_LSMATTRLEN (5 + (LXC_NUMSTRLEN64) + 7 + 1)
-
struct lsm_drv {
const char *name;
--- /dev/null
+/* liblxcapi
+ *
+ * Copyright © 2018 Christian Brauner <christian.brauner@ubuntu.com>.
+ * Copyright © 2018 Canonical Ltd.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __LXC_MACRO_H
+#define __LXC_MACRO_H
+
+#include <asm/types.h>
+#include <limits.h>
+#include <linux/if_link.h>
+#include <linux/loop.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <linux/types.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#ifndef PATH_MAX
+#define PATH_MAX 4096
+#endif
+
+/* Define __S_ISTYPE if missing from the C library. */
+#ifndef __S_ISTYPE
+#define __S_ISTYPE(mode, mask) (((mode)&S_IFMT) == (mask))
+#endif
+
+/* capabilities */
+#ifndef CAP_SYS_ADMIN
+#define CAP_SYS_ADMIN 21
+#endif
+
+#ifndef CAP_SETFCAP
+#define CAP_SETFCAP 31
+#endif
+
+#ifndef CAP_MAC_OVERRIDE
+#define CAP_MAC_OVERRIDE 32
+#endif
+
+#ifndef CAP_MAC_ADMIN
+#define CAP_MAC_ADMIN 33
+#endif
+
+#ifndef CAP_SETUID
+#define CAP_SETUID 7
+#endif
+
+#ifndef CAP_SETGID
+#define CAP_SETGID 6
+#endif
+
+/* prctl */
+#ifndef PR_CAPBSET_READ
+#define PR_CAPBSET_READ 23
+#endif
+
+#ifndef PR_CAPBSET_DROP
+#define PR_CAPBSET_DROP 24
+#endif
+
+/* Control the ambient capability set */
+#ifndef PR_CAP_AMBIENT
+#define PR_CAP_AMBIENT 47
+#endif
+
+#ifndef PR_CAP_AMBIENT_IS_SET
+#define PR_CAP_AMBIENT_IS_SET 1
+#endif
+
+#ifndef PR_CAP_AMBIENT_RAISE
+#define PR_CAP_AMBIENT_RAISE 2
+#endif
+
+#ifndef PR_CAP_AMBIENT_LOWER
+#define PR_CAP_AMBIENT_LOWER 3
+#endif
+
+#ifndef PR_CAP_AMBIENT_CLEAR_ALL
+#define PR_CAP_AMBIENT_CLEAR_ALL 4
+#endif
+
+#ifndef PR_SET_NO_NEW_PRIVS
+#define PR_SET_NO_NEW_PRIVS 38
+#endif
+
+#ifndef PR_GET_NO_NEW_PRIVS
+#define PR_GET_NO_NEW_PRIVS 39
+#endif
+
+/* filesystem magic values */
+#ifndef CGROUP_SUPER_MAGIC
+#define CGROUP_SUPER_MAGIC 0x27e0eb
+#endif
+
+#ifndef CGROUP2_SUPER_MAGIC
+#define CGROUP2_SUPER_MAGIC 0x63677270
+#endif
+
+#ifndef NSFS_MAGIC
+#define NSFS_MAGIC 0x6e736673
+#endif
+
+/* current overlayfs */
+#ifndef OVERLAY_SUPER_MAGIC
+#define OVERLAY_SUPER_MAGIC 0x794c7630
+#endif
+
+/* legacy overlayfs */
+#ifndef OVERLAYFS_SUPER_MAGIC
+#define OVERLAYFS_SUPER_MAGIC 0x794c764f
+#endif
+
+/* Calculate the number of chars needed to represent a given integer as a C
+ * string. Include room for '-' to indicate negative numbers and the \0 byte.
+ * This is based on systemd.
+ */
+#define INTTYPE_TO_STRLEN(type) \
+ (2 + (sizeof(type) <= 1 \
+ ? 3 \
+ : sizeof(type) <= 2 \
+ ? 5 \
+ : sizeof(type) <= 4 \
+ ? 10 \
+ : sizeof(type) <= 8 \
+ ? 20 \
+ : sizeof(int[-2 * (sizeof(type) > 8)])))
+
+/* Useful macros */
+#define LXC_LINELEN 4096
+#define LXC_IDMAPLEN 4096
+#define LXC_MAX_BUFFER 4096
+#define LXC_NUMSTRLEN64 (INTTYPE_TO_STRLEN(intmax_t))
+
+/* /proc/ = 6
+ * +
+ * <pid-as-str> = INTTYPE_TO_STRLEN(pid_t)
+ * +
+ * /fd/ = 4
+ * +
+ * <fd-as-str> = INTTYPE_TO_STRLEN(int)
+ * +
+ * \0 = 1
+ */
+#define LXC_PROC_PID_FD_LEN \
+ (6 + INTTYPE_TO_STRLEN(pid_t) + 4 + INTTYPE_TO_STRLEN(int) + 1)
+
+/* /proc/ = 6
+ * +
+ * <pid-as-str> = INTTYPE_TO_STRLEN(pid_t)
+ * +
+ * /status = 7
+ * +
+ * \0 = 1
+ */
+#define LXC_PROC_STATUS_LEN (6 + INTTYPE_TO_STRLEN(pid_t) + 7 + 1)
+
+/* /proc/ = 6
+ * +
+ * <pid-as-str> = INTTYPE_TO_STRLEN(pid_t)
+ * +
+ * /attr/ = 6
+ * +
+ * /current = 8
+ * +
+ * \0 = 1
+ */
+#define LXC_LSMATTRLEN (6 + INTTYPE_TO_STRLEN(pid_t) + 6 + 8 + 1)
+
+#define LXC_CMD_DATA_MAX (PATH_MAX * 2)
+
+/* loop devices */
+#ifndef LO_FLAGS_AUTOCLEAR
+#define LO_FLAGS_AUTOCLEAR 4
+#endif
+
+#ifndef LOOP_CTL_GET_FREE
+#define LOOP_CTL_GET_FREE 0x4C82
+#endif
+
+/* memfd_create() */
+#ifndef MFD_CLOEXEC
+#define MFD_CLOEXEC 0x0001U
+#endif
+
+#ifndef MFD_ALLOW_SEALING
+#define MFD_ALLOW_SEALING 0x0002U
+#endif
+
+/**
+ * BUILD_BUG_ON - break compile if a condition is true.
+ * @condition: the condition which the compiler should know is false.
+ *
+ * If you have some code which relies on certain constants being equal, or
+ * other compile-time-evaluated condition, you should use BUILD_BUG_ON to
+ * detect if someone changes it.
+ *
+ * The implementation uses gcc's reluctance to create a negative array, but
+ * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments
+ * to inline functions). So as a fallback we use the optimizer; if it can't
+ * prove the condition is false, it will cause a link error on the undefined
+ * "__build_bug_on_failed". This error message can be harder to track down
+ * though, hence the two different methods.
+ */
+#ifndef __OPTIMIZE__
+#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2 * !!(condition)]))
+#else
+extern int __build_bug_on_failed;
+#define BUILD_BUG_ON(condition) \
+ do { \
+ ((void)sizeof(char[1 - 2 * !!(condition)])); \
+ if (condition) \
+ __build_bug_on_failed = 1; \
+ } while (0)
+#endif
+
+#define lxc_iterate_parts(__iterator, __splitme, __separators) \
+ for (char *__p = NULL, *__it = strtok_r(__splitme, __separators, &__p); \
+ (__iterator = __it); \
+ __iterator = __it = strtok_r(NULL, __separators, &__p))
+
+#define prctl_arg(x) ((unsigned long)x)
+
+/* networking */
+#ifndef NETLINK_DUMP_STRICT_CHK
+#define NETLINK_DUMP_STRICT_CHK 12
+#endif
+
+#ifndef SOL_NETLINK
+#define SOL_NETLINK 270
+#endif
+
+#ifndef IFLA_LINKMODE
+#define IFLA_LINKMODE 17
+#endif
+
+#ifndef IFLA_LINKINFO
+#define IFLA_LINKINFO 18
+#endif
+
+#ifndef IFLA_NET_NS_PID
+#define IFLA_NET_NS_PID 19
+#endif
+
+#ifndef IFLA_INFO_KIND
+#define IFLA_INFO_KIND 1
+#endif
+
+#ifndef IFLA_VLAN_ID
+#define IFLA_VLAN_ID 1
+#endif
+
+#ifndef IFLA_INFO_DATA
+#define IFLA_INFO_DATA 2
+#endif
+
+#ifndef VETH_INFO_PEER
+#define VETH_INFO_PEER 1
+#endif
+
+#ifndef IFLA_MACVLAN_MODE
+#define IFLA_MACVLAN_MODE 1
+#endif
+
+#ifndef IFLA_NEW_NETNSID
+#define IFLA_NEW_NETNSID 45
+#endif
+
+#ifdef IFLA_IF_NETNSID
+#ifndef IFLA_TARGET_NETNSID
+#define IFLA_TARGET_NETNSID = IFLA_IF_NETNSID
+#endif
+#else
+#define IFLA_IF_NETNSID 46
+#define IFLA_TARGET_NETNSID 46
+#endif
+
+#ifndef IFA_TARGET_NETNSID
+#define IFA_TARGET_NETNSID 10
+#endif
+
+#ifndef IFLA_STATS
+#define IFLA_STATS 7
+#endif
+
+#ifndef IFLA_STATS64
+#define IFLA_STATS64 23
+#endif
+
+#ifndef RTM_NEWNSID
+#define RTM_NEWNSID 88
+#endif
+
+#ifndef RTM_GETNSID
+#define RTM_GETNSID 90
+#endif
+
+#ifndef NLMSG_ERROR
+#define NLMSG_ERROR 0x2
+#endif
+
+#ifndef MACVLAN_MODE_PRIVATE
+#define MACVLAN_MODE_PRIVATE 1
+#endif
+
+#ifndef MACVLAN_MODE_VEPA
+#define MACVLAN_MODE_VEPA 2
+#endif
+
+#ifndef MACVLAN_MODE_BRIDGE
+#define MACVLAN_MODE_BRIDGE 4
+#endif
+
+#ifndef MACVLAN_MODE_PASSTHRU
+#define MACVLAN_MODE_PASSTHRU 8
+#endif
+
+/* Attributes of RTM_NEWNSID/RTM_GETNSID messages */
+enum {
+ __LXC_NETNSA_NONE,
+#define __LXC_NETNSA_NSID_NOT_ASSIGNED -1
+ __LXC_NETNSA_NSID,
+ __LXC_NETNSA_PID,
+ __LXC_NETNSA_FD,
+ __LXC_NETNSA_MAX,
+};
+
+/* Length of abstract unix domain socket socket address. */
+#define LXC_AUDS_ADDR_LEN sizeof(((struct sockaddr_un *)0)->sun_path)
+
+/* mount */
+#ifndef MS_PRIVATE
+#define MS_PRIVATE (1<<18)
+#endif
+
+#ifndef MS_SLAVE
+#define MS_SLAVE (1 << 19)
+#endif
+
+#ifndef MS_LAZYTIME
+#define MS_LAZYTIME (1<<25)
+#endif
+
+#ifndef MS_REC
+#define MS_REC 16384
+#endif
+
+/* open */
+#ifndef O_PATH
+#define O_PATH 010000000
+#endif
+
+#ifndef O_NOFOLLOW
+#define O_NOFOLLOW 00400000
+#endif
+
+/* sockets */
+#ifndef SOCK_CLOEXEC
+#define SOCK_CLOEXEC 02000000
+#endif
+
+/* pointer conversion macros */
+#define PTR_TO_INT(p) ((int)((intptr_t)(p)))
+#define INT_TO_PTR(u) ((void *)((intptr_t)(u)))
+
+#define PTR_TO_INTMAX(p) ((intmax_t)((intptr_t)(p)))
+#define INTMAX_TO_PTR(u) ((void *)((intptr_t)(u)))
+
+#define LXC_INVALID_UID ((uid_t)-1)
+#define LXC_INVALID_GID ((gid_t)-1)
+
+#define STRLITERALLEN(x) (sizeof(""x"") - 1)
+#define STRARRAYLEN(x) (sizeof(x) - 1)
+
+/* Maximum number of bytes sendfile() is able to send in one go. */
+#define LXC_SENDFILE_MAX 0x7ffff000
+
+#define move_ptr(ptr) \
+ ({ \
+ typeof(ptr) __internal_ptr__ = (ptr); \
+ (ptr) = NULL; \
+ __internal_ptr__; \
+ })
+
+#define move_fd(fd) \
+ ({ \
+ int __internal_fd__ = (fd); \
+ (fd) = -EBADF; \
+ __internal_fd__; \
+ })
+
+#endif /* __LXC_MACRO_H */
--- /dev/null
+/* liblxcapi
+ *
+ * Copyright © 2019 Christian Brauner <christian.brauner@ubuntu.com>.
+ * Copyright © 2019 Canonical Ltd.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __LXC_MEMORY_UTILS_H
+#define __LXC_MEMORY_UTILS_H
+
+#include <dirent.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "macro.h"
+
+static inline void __auto_free__(void *p)
+{
+ free(*(void **)p);
+}
+
+static inline void __auto_fclose__(FILE **f)
+{
+ if (*f)
+ fclose(*f);
+}
+
+static inline void __auto_closedir__(DIR **d)
+{
+ if (*d)
+ closedir(*d);
+}
+
+#define close_prot_errno_disarm(fd) \
+ if (fd >= 0) { \
+ int _e_ = errno; \
+ close(fd); \
+ errno = _e_; \
+ fd = -EBADF; \
+ }
+
+static inline void __auto_close__(int *fd)
+{
+ close_prot_errno_disarm(*fd);
+}
+
+#define __do_close_prot_errno __attribute__((__cleanup__(__auto_close__)))
+#define __do_free __attribute__((__cleanup__(__auto_free__)))
+#define __do_fclose __attribute__((__cleanup__(__auto_fclose__)))
+#define __do_closedir __attribute__((__cleanup__(__auto_closedir__)))
+
+#endif /* __LXC_MEMORY_UTILS_H */
* Copyright © 2019 Christian Brauner <christian.brauner@ubuntu.com>.
* Copyright © 2019 Canonical Ltd.
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2, as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+
+ * This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _GNU_SOURCE
#include <unistd.h>
#include "config.h"
+#include "macro.h"
+#include "memory_utils.h"
#include "utils.h"
#if IS_BIONIC
return NULL;
}
-static int parse_exec_params(char ***argv, char ***envp)
+static int parse_argv(char ***argv)
{
+ __do_free char *cmdline = NULL;
int ret;
- char *cmdline = NULL, *env = NULL;
- size_t cmdline_size, env_size;
+ size_t cmdline_size;
cmdline = file_to_buf("/proc/self/cmdline", &cmdline_size);
if (!cmdline)
- goto on_error;
-
- env = file_to_buf("/proc/self/environ", &env_size);
- if (!env)
- goto on_error;
+ return -1;
ret = push_vargs(cmdline, cmdline_size, argv);
if (ret <= 0)
- goto on_error;
-
- ret = push_vargs(env, env_size, envp);
- if (ret <= 0)
- goto on_error;
+ return -1;
+ move_ptr(cmdline);
return 0;
-
-on_error:
- free(env);
- free(cmdline);
-
- return -1;
}
static int is_memfd(void)
{
- int fd, saved_errno, seals;
+ __do_close_prot_errno int fd = -EBADF;
+ int seals;
fd = open("/proc/self/exe", O_RDONLY | O_CLOEXEC);
if (fd < 0)
return -ENOTRECOVERABLE;
seals = fcntl(fd, F_GET_SEALS);
- saved_errno = errno;
- close(fd);
- errno = saved_errno;
- if (seals < 0)
+ if (seals < 0) {
+ struct stat s = {0};
+
+ if (fstat(fd, &s) == 0)
+ return (s.st_nlink == 0);
+
return -EINVAL;
+ }
return seals == LXC_MEMFD_REXEC_SEALS;
}
return ret;
}
+static int fd_to_fd(int from, int to)
+{
+ for (;;) {
+ uint8_t buf[PATH_MAX];
+ uint8_t *p = buf;
+ ssize_t bytes_to_write;
+ ssize_t bytes_read;
+
+ bytes_read = lxc_read_nointr(from, buf, sizeof buf);
+ if (bytes_read < 0)
+ return -1;
+ if (bytes_read == 0)
+ break;
+
+ bytes_to_write = (size_t)bytes_read;
+ do {
+ ssize_t bytes_written;
+
+ bytes_written = lxc_write_nointr(to, p, bytes_to_write);
+ if (bytes_written < 0)
+ return -1;
+
+ bytes_to_write -= bytes_written;
+ p += bytes_written;
+ } while (bytes_to_write > 0);
+ }
+
+ return 0;
+}
+
static void lxc_rexec_as_memfd(char **argv, char **envp, const char *memfd_name)
{
- int saved_errno;
- ssize_t bytes_sent;
- int fd = -1, memfd = -1;
+ __do_close_prot_errno int execfd = -EBADF, fd = -EBADF, memfd = -EBADF,
+ tmpfd = -EBADF;
+ int ret;
+ ssize_t bytes_sent = 0;
+ struct stat st = {0};
memfd = memfd_create(memfd_name, MFD_ALLOW_SEALING | MFD_CLOEXEC);
- if (memfd < 0)
- return;
+ if (memfd < 0) {
+ char template[PATH_MAX];
+
+ ret = snprintf(template, sizeof(template),
+ P_tmpdir "/.%s_XXXXXX", memfd_name);
+ if (ret < 0 || (size_t)ret >= sizeof(template))
+ return;
+
+ tmpfd = lxc_make_tmpfile(template, true);
+ if (tmpfd < 0)
+ return;
+
+ ret = fchmod(tmpfd, 0700);
+ if (ret)
+ return;
+ }
fd = open("/proc/self/exe", O_RDONLY | O_CLOEXEC);
if (fd < 0)
- goto on_error;
+ return;
/* sendfile() handles up to 2GB. */
- bytes_sent = lxc_sendfile_nointr(memfd, fd, NULL, LXC_SENDFILE_MAX);
- saved_errno = errno;
- close(fd);
- errno = saved_errno;
- if (bytes_sent < 0)
- goto on_error;
+ ret = fstat(fd, &st);
+ if (ret)
+ return;
- if (fcntl(memfd, F_ADD_SEALS, LXC_MEMFD_REXEC_SEALS))
- goto on_error;
+ while (bytes_sent < st.st_size) {
+ ssize_t sent;
+
+ sent = lxc_sendfile_nointr(memfd >= 0 ? memfd : tmpfd, fd, NULL,
+ st.st_size - bytes_sent);
+ if (sent < 0) {
+ /* Fallback to shoveling data between kernel- and
+ * userspace.
+ */
+ lseek(fd, 0, SEEK_SET);
+ if (fd_to_fd(fd, memfd >= 0 ? memfd : tmpfd))
+ break;
+
+ return;
+ }
+ bytes_sent += sent;
+ }
+ close_prot_errno_disarm(fd);
- fexecve(memfd, argv, envp);
+ if (memfd >= 0) {
+ if (fcntl(memfd, F_ADD_SEALS, LXC_MEMFD_REXEC_SEALS))
+ return;
-on_error:
- saved_errno = errno;
- close(memfd);
- errno = saved_errno;
+ execfd = memfd;
+ } else {
+ char procfd[LXC_PROC_PID_FD_LEN];
+
+ ret = snprintf(procfd, sizeof(procfd), "/proc/self/fd/%d", tmpfd);
+ if (ret < 0 || (size_t)ret >= sizeof(procfd))
+ return;
+
+ execfd = open(procfd, O_PATH | O_CLOEXEC);
+ close_prot_errno_disarm(tmpfd);
+
+ }
+ if (execfd < 0)
+ return;
+
+ fexecve(execfd, argv, envp);
}
-static int lxc_rexec(const char *memfd_name)
+/*
+ * Get cheap access to the environment. This must be declared by the user as
+ * mandated by POSIX. The definition is located in unistd.h.
+ */
+extern char **environ;
+
+int lxc_rexec(const char *memfd_name)
{
int ret;
- char **argv = NULL, **envp = NULL;
+ char **argv = NULL;
ret = is_memfd();
if (ret < 0 && ret == -ENOTRECOVERABLE) {
return 0;
}
- ret = parse_exec_params(&argv, &envp);
+ ret = parse_argv(&argv);
if (ret < 0) {
fprintf(stderr,
"%s - Failed to parse command line parameters\n",
return -1;
}
- lxc_rexec_as_memfd(argv, envp, memfd_name);
+ lxc_rexec_as_memfd(argv, environ, memfd_name);
fprintf(stderr, "%s - Failed to rexec as memfd\n", strerror(errno));
return -1;
}
*/
__attribute__((constructor)) static void liblxc_rexec(void)
{
- if (lxc_rexec("liblxc")) {
+ if (getenv("LXC_MEMFD_REXEC") && lxc_rexec("liblxc")) {
fprintf(stderr, "Failed to re-execute liblxc via memory file descriptor\n");
_exit(EXIT_FAILURE);
}
--- /dev/null
+/* liblxcapi
+ *
+ * Copyright © 2019 Christian Brauner <christian.brauner@ubuntu.com>.
+ * Copyright © 2019 Canonical Ltd.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __LXC_REXEC_H
+#define __LXC_REXEC_H
+
+extern int lxc_rexec(const char *memfd_name);
+
+#endif /* __LXC_REXEC_H */
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-#include "config.h"
-
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE 1
+#endif
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <lxc/lxccontainer.h>
-#include "attach.h"
#include "arguments.h"
+#include "attach.h"
#include "caps.h"
#include "conf.h"
+#include "config.h"
#include "confile.h"
#include "console.h"
-#include "log.h"
#include "list.h"
+#include "log.h"
#include "mainloop.h"
+#include "rexec.h"
#include "utils.h"
#if HAVE_PTY_H
#include <../include/openpty.h>
#endif
+/**
+ * This function will copy any binary that calls liblxc into a memory file and
+ * will use the memfd to rexecute the binary. This is done to prevent attacks
+ * through the /proc/self/exe symlink to corrupt the host binary when host and
+ * container are in the same user namespace or have set up an identity id
+ * mapping: CVE-2019-5736.
+ */
+#ifdef ENFORCE_MEMFD_REXEC
+__attribute__((constructor)) static void lxc_attach_rexec(void)
+{
+ if (!getenv("LXC_MEMFD_REXEC") && lxc_rexec("lxc-attach")) {
+ fprintf(stderr, "Failed to re-execute lxc-attach via memory file descriptor\n");
+ _exit(EXIT_FAILURE);
+ }
+}
+#endif
+
static const struct option my_longopts[] = {
{"elevated-privileges", optional_argument, 0, 'e'},
{"arch", required_argument, 0, 'a'},
#include "log.h"
#include "lxclock.h"
+#include "memory_utils.h"
#include "namespace.h"
#include "parse.h"
#include "utils.h"
int lxc_make_tmpfile(char *template, bool rm)
{
- int fd, ret;
+ __do_close_prot_errno int fd = -EBADF;
+ int ret;
mode_t msk;
msk = umask(0022);
if (fd < 0)
return -1;
+ if (lxc_set_cloexec(fd))
+ return -1;
+
if (!rm)
- return fd;
+ return move_fd(fd);
ret = unlink(template);
- if (ret < 0) {
- close(fd);
+ if (ret < 0)
return -1;
- }
- return fd;
+ return move_fd(fd);
}
int parse_byte_size_string(const char *s, int64_t *converted)
#endif
#include "initutils.h"
-
-/* Define __S_ISTYPE if missing from the C library. */
-#ifndef __S_ISTYPE
-#define __S_ISTYPE(mode, mask) (((mode)&S_IFMT) == (mask))
-#endif
-
-#if HAVE_LIBCAP
-#ifndef CAP_SETFCAP
-#define CAP_SETFCAP 31
-#endif
-
-#ifndef CAP_MAC_OVERRIDE
-#define CAP_MAC_OVERRIDE 32
-#endif
-
-#ifndef CAP_MAC_ADMIN
-#define CAP_MAC_ADMIN 33
-#endif
-#endif
-
-#ifndef PR_CAPBSET_DROP
-#define PR_CAPBSET_DROP 24
-#endif
-
-#ifndef LO_FLAGS_AUTOCLEAR
-#define LO_FLAGS_AUTOCLEAR 4
-#endif
-
-#ifndef CAP_SETUID
-#define CAP_SETUID 7
-#endif
-
-#ifndef CAP_SETGID
-#define CAP_SETGID 6
-#endif
-
-/* needed for cgroup automount checks, regardless of whether we
- * have included linux/capability.h or not */
-#ifndef CAP_SYS_ADMIN
-#define CAP_SYS_ADMIN 21
-#endif
-
-#ifndef CGROUP_SUPER_MAGIC
-#define CGROUP_SUPER_MAGIC 0x27e0eb
-#endif
-
-#ifndef CGROUP2_SUPER_MAGIC
-#define CGROUP2_SUPER_MAGIC 0x63677270
-#endif
-
-#ifndef NSFS_MAGIC
-#define NSFS_MAGIC 0x6e736673
-#endif
-
-/* Useful macros */
-/* Maximum number for 64 bit integer is a string with 21 digits: 2^64 - 1 = 21 */
-#define LXC_NUMSTRLEN64 21
-#define LXC_LINELEN 4096
-#define LXC_IDMAPLEN 4096
-/* /proc/ = 6
- * +
- * <pid-as-str> = LXC_NUMSTRLEN64
- * +
- * /fd/ = 4
- * +
- * <fd-as-str> = LXC_NUMSTRLEN64
- * +
- * \0 = 1
- */
-#define LXC_PROC_PID_FD_LEN (6 + LXC_NUMSTRLEN64 + 4 + LXC_NUMSTRLEN64 + 1)
+#include "macro.h"
/* returns 1 on success, 0 if there were any failures */
extern int lxc_rmdir_onedev(char *path, const char *exclude);
*/
extern int lxc_pclose(struct lxc_popen_FILE *fp);
-/**
- * BUILD_BUG_ON - break compile if a condition is true.
- * @condition: the condition which the compiler should know is false.
- *
- * If you have some code which relies on certain constants being equal, or
- * other compile-time-evaluated condition, you should use BUILD_BUG_ON to
- * detect if someone changes it.
- *
- * The implementation uses gcc's reluctance to create a negative array, but
- * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments
- * to inline functions). So as a fallback we use the optimizer; if it can't
- * prove the condition is false, it will cause a link error on the undefined
- * "__build_bug_on_failed". This error message can be harder to track down
- * though, hence the two different methods.
- */
-#ifndef __OPTIMIZE__
-#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
-#else
-extern int __build_bug_on_failed;
-#define BUILD_BUG_ON(condition) \
- do { \
- ((void)sizeof(char[1 - 2*!!(condition)])); \
- if (condition) __build_bug_on_failed = 1; \
- } while(0)
-#endif
-
/*
* wait on a child we forked
*/
projects / thirdparty / lxc.git / commitdiff
