From 2eedfd2d8b3441e8cf6dae4bdc9afaefbda19c39 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 23 Dec 2016 11:09:47 +0100
Subject: dissect: make sure to manually follow symlinks when mounting
 dissected image

If the dissected image contains symlinks for the mount points we need we
need to make sure to follow this with chase_symlinks() so that we don't
leave the image.
---
 src/shared/dissect-image.c | 39 ++++++++++++++++++++++++---------------
 1 file changed, 24 insertions(+), 15 deletions(-)

(limited to 'src/shared/dissect-image.c')

diff --git a/src/shared/dissect-image.c b/src/shared/dissect-image.c
index 878cb008aa..5fc2ce25f0 100644
--- a/src/shared/dissect-image.c
+++ b/src/shared/dissect-image.c
@@ -28,6 +28,7 @@
 #include "blkid-util.h"
 #include "dissect-image.h"
 #include "fd-util.h"
+#include "fs-util.h"
 #include "gpt.h"
 #include "mount-util.h"
 #include "path-util.h"
@@ -35,6 +36,7 @@
 #include "stdio-util.h"
 #include "string-table.h"
 #include "string-util.h"
+#include "strv.h"
 #include "udev-util.h"
 
 static int probe_filesystem(const char *node, char **ret_fstype) {
@@ -624,7 +626,9 @@ static int mount_partition(
                 DissectImageFlags flags) {
 
         const char *p, *options = NULL, *node, *fstype;
+        _cleanup_free_ char *chased = NULL;
         bool rw;
+        int r;
 
         assert(m);
         assert(where);
@@ -641,9 +645,13 @@ static int mount_partition(
 
         rw = m->rw && !(flags & DISSECT_IMAGE_READ_ONLY);
 
-        if (directory)
-                p = strjoina(where, directory);
-        else
+        if (directory) {
+                r = chase_symlinks(directory, where, CHASE_PREFIX_ROOT, &chased);
+                if (r < 0)
+                        return r;
+
+                p = chased;
+        } else
                 p = where;
 
         /* If requested, turn on discard support. */
@@ -677,22 +685,23 @@ int dissected_image_mount(DissectedImage *m, const char *where, DissectImageFlag
                 return r;
 
         if (m->partitions[PARTITION_ESP].found) {
-                const char *mp, *x;
+                const char *mp;
 
                 /* Mount the ESP to /efi if it exists and is empty. If it doesn't exist, use /boot instead. */
 
-                mp = "/efi";
-                x = strjoina(where, mp);
-                r = dir_is_empty(x);
-                if (r == -ENOENT) {
-                        mp = "/boot";
-                        x = strjoina(where, mp);
-                        r = dir_is_empty(x);
-                }
-                if (r > 0) {
-                        r = mount_partition(m->partitions + PARTITION_ESP, where, mp, flags);
+                FOREACH_STRING(mp, "/efi", "/boot") {
+                        _cleanup_free_ char *p = NULL;
+
+                        r = chase_symlinks(mp, where, CHASE_PREFIX_ROOT, &p);
                         if (r < 0)
-                                return r;
+                                continue;
+
+                        r = dir_is_empty(p);
+                        if (r > 0) {
+                                r = mount_partition(m->partitions + PARTITION_ESP, where, mp, flags);
+                                if (r < 0)
+                                        return r;
+                        }
                 }
         }
 
-- 
cgit v1.2.3-54-g00ecf