bootctl,bootspec: make use of CHASE_PROHIBIT_SYMLINKS whenever we access the ESP/XBOOTLDR

Let's make use of the new flag whenever we access the ESP or XBOOTLDR.
The resources we make use of in these partitions can't possibly use
symlinks (because UEFI knows no symlink concept), and they are untrusted
territory, hence under no circumstances we should be tricked into
following symlinks that shouldn't be there in the first place.

Of course, you might argue thta ESP/XBOOTLDR are VFAT and thus don#t
know symlinks. But the thing is, they don#t have to be. Firmware can
support other file systems too, and people can use efifs to gain access
to arbitrary Linux file systems from EFI. Hence, let's better be safe
than sorry.

1 files changed, 9 insertions, 9 deletions

diff --git a/src/boot/bootctl.c b/src/boot/bootctl.c
index 79b2676537..0f142bff87 100644
--- a/src/boot/bootctl.c
+++ b/src/boot/bootctl.c
@@ -484,7 +484,7 @@ static int enumerate_binaries(
         assert(previous);
         assert(is_first);
 
-        r = chase_symlinks_and_opendir(path, esp_path, CHASE_PREFIX_ROOT, &p, &d);
+        r = chase_symlinks_and_opendir(path, esp_path, CHASE_PREFIX_ROOT|CHASE_PROHIBIT_SYMLINKS, &p, &d);
         if (r == -ENOENT)
                 return 0;
         if (r < 0)
@@ -913,10 +913,10 @@ static int copy_one_file(const char *esp_path, const char *name, bool force) {
         if (!p)
                 return log_oom();
 
-        r = chase_symlinks(p, root, CHASE_PREFIX_ROOT, &source_path, NULL);
+        r = chase_symlinks(p, root, CHASE_PREFIX_ROOT|CHASE_PROHIBIT_SYMLINKS, &source_path, NULL);
         /* If we had a root directory to try, we didn't find it and we are in auto mode, retry on the host */
         if (r == -ENOENT && root && arg_install_source == ARG_INSTALL_SOURCE_AUTO)
-                r = chase_symlinks(p, NULL, CHASE_PREFIX_ROOT, &source_path, NULL);
+                r = chase_symlinks(p, NULL, CHASE_PREFIX_ROOT|CHASE_PROHIBIT_SYMLINKS, &source_path, NULL);
         if (r < 0)
                 return log_error_errno(r,
                                        "Failed to resolve path %s%s%s: %m",
@@ -928,7 +928,7 @@ static int copy_one_file(const char *esp_path, const char *name, bool force) {
         if (!q)
                 return log_oom();
 
-        r = chase_symlinks(q, esp_path, CHASE_PREFIX_ROOT | CHASE_NONEXISTENT, &dest_path, NULL);
+        r = chase_symlinks(q, esp_path, CHASE_PREFIX_ROOT|CHASE_PROHIBIT_SYMLINKS|CHASE_NONEXISTENT, &dest_path, NULL);
         if (r < 0)
                 return log_error_errno(r, "Failed to resolve path %s under directory %s: %m", q, esp_path);
 
@@ -945,7 +945,7 @@ static int copy_one_file(const char *esp_path, const char *name, bool force) {
                 v = strjoina("/EFI/BOOT/BOOT", e);
                 ascii_strupper(strrchr(v, '/') + 1);
 
-                r = chase_symlinks(v, esp_path, CHASE_PREFIX_ROOT | CHASE_NONEXISTENT, &default_dest_path, NULL);
+                r = chase_symlinks(v, esp_path, CHASE_PREFIX_ROOT|CHASE_PROHIBIT_SYMLINKS|CHASE_NONEXISTENT, &default_dest_path, NULL);
                 if (r < 0)
                         return log_error_errno(r, "Failed to resolve path %s under directory %s: %m", v, esp_path);
 
@@ -963,10 +963,10 @@ static int install_binaries(const char *esp_path, const char *arch, bool force)
         _cleanup_free_ char *path = NULL;
         int r;
 
-        r = chase_symlinks_and_opendir(BOOTLIBDIR, root, CHASE_PREFIX_ROOT, &path, &d);
+        r = chase_symlinks_and_opendir(BOOTLIBDIR, root, CHASE_PREFIX_ROOT|CHASE_PROHIBIT_SYMLINKS, &path, &d);
         /* If we had a root directory to try, we didn't find it and we are in auto mode, retry on the host */
         if (r == -ENOENT && root && arg_install_source == ARG_INSTALL_SOURCE_AUTO)
-                r = chase_symlinks_and_opendir(BOOTLIBDIR, NULL, CHASE_PREFIX_ROOT, &path, &d);
+                r = chase_symlinks_and_opendir(BOOTLIBDIR, NULL, CHASE_PREFIX_ROOT|CHASE_PROHIBIT_SYMLINKS, &path, &d);
         if (r < 0)
                 return log_error_errno(r, "Failed to open boot loader directory %s%s: %m", strempty(root), BOOTLIBDIR);
 
@@ -1136,7 +1136,7 @@ static int install_variables(
                 return 0;
         }
 
-        r = chase_symlinks_and_access(path, esp_path, CHASE_PREFIX_ROOT, F_OK, NULL, NULL);
+        r = chase_symlinks_and_access(path, esp_path, CHASE_PREFIX_ROOT|CHASE_PROHIBIT_SYMLINKS, F_OK, NULL, NULL);
         if (r == -ENOENT)
                 return 0;
         if (r < 0)
@@ -1167,7 +1167,7 @@ static int remove_boot_efi(const char *esp_path) {
         _cleanup_free_ char *p = NULL;
         int r, c = 0;
 
-        r = chase_symlinks_and_opendir("/EFI/BOOT", esp_path, CHASE_PREFIX_ROOT, &p, &d);
+        r = chase_symlinks_and_opendir("/EFI/BOOT", esp_path, CHASE_PREFIX_ROOT|CHASE_PROHIBIT_SYMLINKS, &p, &d);
         if (r == -ENOENT)
                 return 0;
         if (r < 0)