Adding upstream version 241.upstream/241upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 453 insertions, 0 deletions

diff --git a/src/shared/clean-ipc.c b/src/shared/clean-ipc.c
new file mode 100644
index 0000000..46fa680
--- /dev/null
+++ b/src/shared/clean-ipc.c
@@ -0,0 +1,453 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <mqueue.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/ipc.h>
+#include <sys/msg.h>
+#include <sys/sem.h>
+#include <sys/shm.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "clean-ipc.h"
+#include "dirent-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "format-util.h"
+#include "log.h"
+#include "macro.h"
+#include "string-util.h"
+#include "strv.h"
+#include "user-util.h"
+
+static bool match_uid_gid(uid_t subject_uid, gid_t subject_gid, uid_t delete_uid, gid_t delete_gid) {
+
+        if (uid_is_valid(delete_uid) && subject_uid == delete_uid)
+                return true;
+
+        if (gid_is_valid(delete_gid) && subject_gid == delete_gid)
+                return true;
+
+        return false;
+}
+
+static int clean_sysvipc_shm(uid_t delete_uid, gid_t delete_gid, bool rm) {
+        _cleanup_fclose_ FILE *f = NULL;
+        bool first = true;
+        int ret = 0, r;
+
+        f = fopen("/proc/sysvipc/shm", "re");
+        if (!f) {
+                if (errno == ENOENT)
+                        return 0;
+
+                return log_warning_errno(errno, "Failed to open /proc/sysvipc/shm: %m");
+        }
+
+        for (;;) {
+                _cleanup_free_ char *line = NULL;
+                unsigned n_attached;
+                pid_t cpid, lpid;
+                uid_t uid, cuid;
+                gid_t gid, cgid;
+                int shmid;
+
+                r = read_line(f, LONG_LINE_MAX, &line);
+                if (r < 0)
+                        return log_warning_errno(errno, "Failed to read /proc/sysvipc/shm: %m");
+                if (r == 0)
+                        break;
+
+                if (first) {
+                        first = false;
+                        continue;
+                }
+
+                if (sscanf(line, "%*i %i %*o %*u " PID_FMT " " PID_FMT " %u " UID_FMT " " GID_FMT " " UID_FMT " " GID_FMT,
+                           &shmid, &cpid, &lpid, &n_attached, &uid, &gid, &cuid, &cgid) != 8)
+                        continue;
+
+                if (n_attached > 0)
+                        continue;
+
+                if (!match_uid_gid(uid, gid, delete_uid, delete_gid))
+                        continue;
+
+                if (!rm)
+                        return 1;
+
+                if (shmctl(shmid, IPC_RMID, NULL) < 0) {
+
+                        /* Ignore entries that are already deleted */
+                        if (IN_SET(errno, EIDRM, EINVAL))
+                                continue;
+
+                        ret = log_warning_errno(errno,
+                                                "Failed to remove SysV shared memory segment %i: %m",
+                                                shmid);
+                } else {
+                        log_debug("Removed SysV shared memory segment %i.", shmid);
+                        if (ret == 0)
+                                ret = 1;
+                }
+        }
+
+        return ret;
+}
+
+static int clean_sysvipc_sem(uid_t delete_uid, gid_t delete_gid, bool rm) {
+        _cleanup_fclose_ FILE *f = NULL;
+        bool first = true;
+        int ret = 0, r;
+
+        f = fopen("/proc/sysvipc/sem", "re");
+        if (!f) {
+                if (errno == ENOENT)
+                        return 0;
+
+                return log_warning_errno(errno, "Failed to open /proc/sysvipc/sem: %m");
+        }
+
+        for (;;) {
+                _cleanup_free_ char *line = NULL;
+                uid_t uid, cuid;
+                gid_t gid, cgid;
+                int semid;
+
+                r = read_line(f, LONG_LINE_MAX, &line);
+                if (r < 0)
+                        return log_warning_errno(r, "Failed to read /proc/sysvipc/sem: %m");
+                if (r == 0)
+                        break;
+
+                if (first) {
+                        first = false;
+                        continue;
+                }
+
+                if (sscanf(line, "%*i %i %*o %*u " UID_FMT " " GID_FMT " " UID_FMT " " GID_FMT,
+                           &semid, &uid, &gid, &cuid, &cgid) != 5)
+                        continue;
+
+                if (!match_uid_gid(uid, gid, delete_uid, delete_gid))
+                        continue;
+
+                if (!rm)
+                        return 1;
+
+                if (semctl(semid, 0, IPC_RMID) < 0) {
+
+                        /* Ignore entries that are already deleted */
+                        if (IN_SET(errno, EIDRM, EINVAL))
+                                continue;
+
+                        ret = log_warning_errno(errno,
+                                                "Failed to remove SysV semaphores object %i: %m",
+                                                semid);
+                } else {
+                        log_debug("Removed SysV semaphore %i.", semid);
+                        if (ret == 0)
+                                ret = 1;
+                }
+        }
+
+        return ret;
+}
+
+static int clean_sysvipc_msg(uid_t delete_uid, gid_t delete_gid, bool rm) {
+        _cleanup_fclose_ FILE *f = NULL;
+        bool first = true;
+        int ret = 0, r;
+
+        f = fopen("/proc/sysvipc/msg", "re");
+        if (!f) {
+                if (errno == ENOENT)
+                        return 0;
+
+                return log_warning_errno(errno, "Failed to open /proc/sysvipc/msg: %m");
+        }
+
+        for (;;) {
+                _cleanup_free_ char *line = NULL;
+                uid_t uid, cuid;
+                gid_t gid, cgid;
+                pid_t cpid, lpid;
+                int msgid;
+
+                r = read_line(f, LONG_LINE_MAX, &line);
+                if (r < 0)
+                        return log_warning_errno(r, "Failed to read /proc/sysvipc/msg: %m");
+                if (r == 0)
+                        break;
+
+                if (first) {
+                        first = false;
+                        continue;
+                }
+
+                if (sscanf(line, "%*i %i %*o %*u %*u " PID_FMT " " PID_FMT " " UID_FMT " " GID_FMT " " UID_FMT " " GID_FMT,
+                           &msgid, &cpid, &lpid, &uid, &gid, &cuid, &cgid) != 7)
+                        continue;
+
+                if (!match_uid_gid(uid, gid, delete_uid, delete_gid))
+                        continue;
+
+                if (!rm)
+                        return 1;
+
+                if (msgctl(msgid, IPC_RMID, NULL) < 0) {
+
+                        /* Ignore entries that are already deleted */
+                        if (IN_SET(errno, EIDRM, EINVAL))
+                                continue;
+
+                        ret = log_warning_errno(errno,
+                                                "Failed to remove SysV message queue %i: %m",
+                                                msgid);
+                } else {
+                        log_debug("Removed SysV message queue %i.", msgid);
+                        if (ret == 0)
+                                ret = 1;
+                }
+        }
+
+        return ret;
+}
+
+static int clean_posix_shm_internal(DIR *dir, uid_t uid, gid_t gid, bool rm) {
+        struct dirent *de;
+        int ret = 0, r;
+
+        assert(dir);
+
+        FOREACH_DIRENT_ALL(de, dir, goto fail) {
+                struct stat st;
+
+                if (dot_or_dot_dot(de->d_name))
+                        continue;
+
+                if (fstatat(dirfd(dir), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {
+                        if (errno == ENOENT)
+                                continue;
+
+                        ret = log_warning_errno(errno, "Failed to stat() POSIX shared memory segment %s: %m", de->d_name);
+                        continue;
+                }
+
+                if (S_ISDIR(st.st_mode)) {
+                        _cleanup_closedir_ DIR *kid;
+
+                        kid = xopendirat(dirfd(dir), de->d_name, O_NOFOLLOW|O_NOATIME);
+                        if (!kid) {
+                                if (errno != ENOENT)
+                                        ret = log_warning_errno(errno, "Failed to enter shared memory directory %s: %m", de->d_name);
+                        } else {
+                                r = clean_posix_shm_internal(kid, uid, gid, rm);
+                                if (r < 0)
+                                        ret = r;
+                        }
+
+                        if (!match_uid_gid(st.st_uid, st.st_gid, uid, gid))
+                                continue;
+
+                        if (!rm)
+                                return 1;
+
+                        if (unlinkat(dirfd(dir), de->d_name, AT_REMOVEDIR) < 0) {
+
+                                if (errno == ENOENT)
+                                        continue;
+
+                                ret = log_warning_errno(errno, "Failed to remove POSIX shared memory directory %s: %m", de->d_name);
+                        } else {
+                                log_debug("Removed POSIX shared memory directory %s", de->d_name);
+                                if (ret == 0)
+                                        ret = 1;
+                        }
+                } else {
+
+                        if (!match_uid_gid(st.st_uid, st.st_gid, uid, gid))
+                                continue;
+
+                        if (!rm)
+                                return 1;
+
+                        if (unlinkat(dirfd(dir), de->d_name, 0) < 0) {
+
+                                if (errno == ENOENT)
+                                        continue;
+
+                                ret = log_warning_errno(errno, "Failed to remove POSIX shared memory segment %s: %m", de->d_name);
+                        } else {
+                                log_debug("Removed POSIX shared memory segment %s", de->d_name);
+                                if (ret == 0)
+                                        ret = 1;
+                        }
+                }
+        }
+
+        return ret;
+
+fail:
+        return log_warning_errno(errno, "Failed to read /dev/shm: %m");
+}
+
+static int clean_posix_shm(uid_t uid, gid_t gid, bool rm) {
+        _cleanup_closedir_ DIR *dir = NULL;
+
+        dir = opendir("/dev/shm");
+        if (!dir) {
+                if (errno == ENOENT)
+                        return 0;
+
+                return log_warning_errno(errno, "Failed to open /dev/shm: %m");
+        }
+
+        return clean_posix_shm_internal(dir, uid, gid, rm);
+}
+
+static int clean_posix_mq(uid_t uid, gid_t gid, bool rm) {
+        _cleanup_closedir_ DIR *dir = NULL;
+        struct dirent *de;
+        int ret = 0;
+
+        dir = opendir("/dev/mqueue");
+        if (!dir) {
+                if (errno == ENOENT)
+                        return 0;
+
+                return log_warning_errno(errno, "Failed to open /dev/mqueue: %m");
+        }
+
+        FOREACH_DIRENT_ALL(de, dir, goto fail) {
+                struct stat st;
+                char fn[1+strlen(de->d_name)+1];
+
+                if (dot_or_dot_dot(de->d_name))
+                        continue;
+
+                if (fstatat(dirfd(dir), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {
+                        if (errno == ENOENT)
+                                continue;
+
+                        ret = log_warning_errno(errno,
+                                                "Failed to stat() MQ segment %s: %m",
+                                                de->d_name);
+                        continue;
+                }
+
+                if (!match_uid_gid(st.st_uid, st.st_gid, uid, gid))
+                        continue;
+
+                if (!rm)
+                        return 1;
+
+                fn[0] = '/';
+                strcpy(fn+1, de->d_name);
+
+                if (mq_unlink(fn) < 0) {
+                        if (errno == ENOENT)
+                                continue;
+
+                        ret = log_warning_errno(errno,
+                                                "Failed to unlink POSIX message queue %s: %m",
+                                                fn);
+                } else {
+                        log_debug("Removed POSIX message queue %s", fn);
+                        if (ret == 0)
+                                ret = 1;
+                }
+        }
+
+        return ret;
+
+fail:
+        return log_warning_errno(errno, "Failed to read /dev/mqueue: %m");
+}
+
+int clean_ipc_internal(uid_t uid, gid_t gid, bool rm) {
+        int ret = 0, r;
+
+        /* If 'rm' is true, clean all IPC objects owned by either the specified UID or the specified GID. Return the
+         * last error encountered or == 0 if no matching IPC objects have been found or > 0 if matching IPC objects
+         * have been found and have been removed.
+         *
+         * If 'rm' is false, just search for IPC objects owned by either the specified UID or the specified GID. In
+         * this case we return < 0 on error, > 0 if we found a matching object, == 0 if we didn't.
+         *
+         * As special rule: if UID/GID is specified as root we'll silently not clean up things, and always claim that
+         * there are IPC objects for it. */
+
+        if (uid == 0) {
+                if (!rm)
+                        return 1;
+
+                uid = UID_INVALID;
+        }
+        if (gid == 0) {
+                if (!rm)
+                        return 1;
+
+                gid = GID_INVALID;
+        }
+
+        /* Anything to do? */
+        if (!uid_is_valid(uid) && !gid_is_valid(gid))
+                return 0;
+
+        r = clean_sysvipc_shm(uid, gid, rm);
+        if (r != 0) {
+                if (!rm)
+                        return r;
+                if (ret == 0)
+                        ret = r;
+        }
+
+        r = clean_sysvipc_sem(uid, gid, rm);
+        if (r != 0) {
+                if (!rm)
+                        return r;
+                if (ret == 0)
+                        ret = r;
+        }
+
+        r = clean_sysvipc_msg(uid, gid, rm);
+        if (r != 0) {
+                if (!rm)
+                        return r;
+                if (ret == 0)
+                        ret = r;
+        }
+
+        r = clean_posix_shm(uid, gid, rm);
+        if (r != 0) {
+                if (!rm)
+                        return r;
+                if (ret == 0)
+                        ret = r;
+        }
+
+        r = clean_posix_mq(uid, gid, rm);
+        if (r != 0) {
+                if (!rm)
+                        return r;
+                if (ret == 0)
+                        ret = r;
+        }
+
+        return ret;
+}
+
+int clean_ipc_by_uid(uid_t uid) {
+        return clean_ipc_internal(uid, GID_INVALID, true);
+}
+
+int clean_ipc_by_gid(gid_t gid) {
+        return clean_ipc_internal(UID_INVALID, gid, true);
+}