dpkg: prevent important directories from being removed
busybox will remove directory symlinks, which is at
odds with common layouts that have some of
bin/lib/lib32/lib64 symlinked.
this adds a exludelist for critcal and often symlinked
directories.
Fixes: Bug 12551
function old new delta
remove_file_array 139 231 +92
Signed-off-by: Norbert Lange <nolange79@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/archival/dpkg.c b/archival/dpkg.c
index da77fba..68a40bf 100644
--- a/archival/dpkg.c
+++ b/archival/dpkg.c
@@ -1204,6 +1204,27 @@
return file_list;
}
+/** This tests if the filename is an "important" directory, which might be symlinked.
+ * Debians dpkg test if directories are used by other packages, this
+ * implementation doesn't and would remove for ex. an lib -> usr/lib symlink.
+ */
+static int is_builtin_exclude(const char *name)
+{
+ if (*name++ != '/')
+ return 0;
+ if (index_in_strings(".\0" "etc\0" "opt\0" "srv\0" "var\0" "var/lib\0",
+ name) >= 0)
+ return 1;
+ if (is_prefixed_with(name, "usr/")) {
+ name += sizeof("usr/") - 1;
+ if (is_prefixed_with(name, "local/"))
+ name += sizeof("local/") - 1;
+ }
+
+ return index_in_strings("bin\0" "lib\0" "lib32\0" "lib64\0" "sbin\0",
+ name) >= 0;
+}
+
/* maybe i should try and hook this into remove_file.c somehow */
static int remove_file_array(char **remove_names, char **exclude_names)
{
@@ -1215,6 +1236,8 @@
return 0;
}
for (i = 0; remove_names[i] != NULL; i++) {
+ if (is_builtin_exclude(remove_names[i]))
+ continue;
if (exclude_names != NULL) {
for (j = 0; exclude_names[j] != NULL; j++) {
if (strcmp(remove_names[i], exclude_names[j]) == 0) {