summaryrefslogtreecommitdiff
path: root/src/basic/mount-util.c
diff options
context:
space:
mode:
authorEvgeny Vereshchagin <evvers@ya.ru>2016-09-28 04:50:30 +0300
committerGitHub <noreply@github.com>2016-09-28 04:50:30 +0300
commitcc238590e472e8bbba6da262ac985ea59ad52c72 (patch)
treefc9754e546ccb3a6355bd4157bc590ab93478469 /src/basic/mount-util.c
parentb8fafaf4a1cffd02389d61ed92ca7acb1b8c739c (diff)
parentcdfbd1fb26eb75fe6beca47dce7e5e348b077d97 (diff)
Merge pull request #4185 from endocode/djalal-sandbox-first-protection-v1
core:sandbox: Add new ProtectKernelTunables=, ProtectControlGroups=, ProtectSystem=strict and fixes
Diffstat (limited to 'src/basic/mount-util.c')
-rw-r--r--src/basic/mount-util.c71
1 files changed, 48 insertions, 23 deletions
diff --git a/src/basic/mount-util.c b/src/basic/mount-util.c
index bfa04394fe..b9affb4e70 100644
--- a/src/basic/mount-util.c
+++ b/src/basic/mount-util.c
@@ -36,6 +36,7 @@
#include "set.h"
#include "stdio-util.h"
#include "string-util.h"
+#include "strv.h"
static int fd_fdinfo_mnt_id(int fd, const char *filename, int flags, int *mnt_id) {
char path[strlen("/proc/self/fdinfo/") + DECIMAL_STR_MAX(int)];
@@ -287,10 +288,12 @@ int umount_recursive(const char *prefix, int flags) {
continue;
if (umount2(p, flags) < 0) {
- r = -errno;
+ r = log_debug_errno(errno, "Failed to umount %s: %m", p);
continue;
}
+ log_debug("Successfully unmounted %s", p);
+
again = true;
n++;
@@ -311,24 +314,21 @@ static int get_mount_flags(const char *path, unsigned long *flags) {
return 0;
}
-int bind_remount_recursive(const char *prefix, bool ro) {
+int bind_remount_recursive(const char *prefix, bool ro, char **blacklist) {
_cleanup_set_free_free_ Set *done = NULL;
_cleanup_free_ char *cleaned = NULL;
int r;
- /* Recursively remount a directory (and all its submounts)
- * read-only or read-write. If the directory is already
- * mounted, we reuse the mount and simply mark it
- * MS_BIND|MS_RDONLY (or remove the MS_RDONLY for read-write
- * operation). If it isn't we first make it one. Afterwards we
- * apply MS_BIND|MS_RDONLY (or remove MS_RDONLY) to all
- * submounts we can access, too. When mounts are stacked on
- * the same mount point we only care for each individual
- * "top-level" mount on each point, as we cannot
- * influence/access the underlying mounts anyway. We do not
- * have any effect on future submounts that might get
- * propagated, they migt be writable. This includes future
- * submounts that have been triggered via autofs. */
+ /* Recursively remount a directory (and all its submounts) read-only or read-write. If the directory is already
+ * mounted, we reuse the mount and simply mark it MS_BIND|MS_RDONLY (or remove the MS_RDONLY for read-write
+ * operation). If it isn't we first make it one. Afterwards we apply MS_BIND|MS_RDONLY (or remove MS_RDONLY) to
+ * all submounts we can access, too. When mounts are stacked on the same mount point we only care for each
+ * individual "top-level" mount on each point, as we cannot influence/access the underlying mounts anyway. We
+ * do not have any effect on future submounts that might get propagated, they migt be writable. This includes
+ * future submounts that have been triggered via autofs.
+ *
+ * If the "blacklist" parameter is specified it may contain a list of subtrees to exclude from the
+ * remount operation. Note that we'll ignore the blacklist for the top-level path. */
cleaned = strdup(prefix);
if (!cleaned)
@@ -385,6 +385,33 @@ int bind_remount_recursive(const char *prefix, bool ro) {
if (r < 0)
return r;
+ if (!path_startswith(p, cleaned))
+ continue;
+
+ /* Ignore this mount if it is blacklisted, but only if it isn't the top-level mount we shall
+ * operate on. */
+ if (!path_equal(cleaned, p)) {
+ bool blacklisted = false;
+ char **i;
+
+ STRV_FOREACH(i, blacklist) {
+
+ if (path_equal(*i, cleaned))
+ continue;
+
+ if (!path_startswith(*i, cleaned))
+ continue;
+
+ if (path_startswith(p, *i)) {
+ blacklisted = true;
+ log_debug("Not remounting %s, because blacklisted by %s, called for %s", p, *i, cleaned);
+ break;
+ }
+ }
+ if (blacklisted)
+ continue;
+ }
+
/* Let's ignore autofs mounts. If they aren't
* triggered yet, we want to avoid triggering
* them, as we don't make any guarantees for
@@ -396,12 +423,9 @@ int bind_remount_recursive(const char *prefix, bool ro) {
continue;
}
- if (path_startswith(p, cleaned) &&
- !set_contains(done, p)) {
-
+ if (!set_contains(done, p)) {
r = set_consume(todo, p);
p = NULL;
-
if (r == -EEXIST)
continue;
if (r < 0)
@@ -418,8 +442,7 @@ int bind_remount_recursive(const char *prefix, bool ro) {
if (!set_contains(done, cleaned) &&
!set_contains(todo, cleaned)) {
- /* The prefix directory itself is not yet a
- * mount, make it one. */
+ /* The prefix directory itself is not yet a mount, make it one. */
if (mount(cleaned, cleaned, NULL, MS_BIND|MS_REC, NULL) < 0)
return -errno;
@@ -430,6 +453,8 @@ int bind_remount_recursive(const char *prefix, bool ro) {
if (mount(NULL, prefix, NULL, orig_flags|MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0)
return -errno;
+ log_debug("Made top-level directory %s a mount point.", prefix);
+
x = strdup(cleaned);
if (!x)
return -ENOMEM;
@@ -447,8 +472,7 @@ int bind_remount_recursive(const char *prefix, bool ro) {
if (r < 0)
return r;
- /* Deal with mount points that are obstructed by a
- * later mount */
+ /* Deal with mount points that are obstructed by a later mount */
r = path_is_mount_point(x, 0);
if (r == -ENOENT || r == 0)
continue;
@@ -463,6 +487,7 @@ int bind_remount_recursive(const char *prefix, bool ro) {
if (mount(NULL, x, NULL, orig_flags|MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0)
return -errno;
+ log_debug("Remounted %s read-only.", x);
}
}
}