From 22b912628e0175f55f3aae17dc73b154cb368976 Mon Sep 17 00:00:00 2001 From: Jeff Sharkey Date: Mon, 14 Dec 2015 11:02:01 -0700 Subject: [PATCH] Re-derive permissions after package changes. When packages change, existing package-specific directories may have gained/lost a UID mapping, so we need to update the permissions for any in-memory nodes. This allows an app to deliver data for another package before that package is installed, which is the typical pattern of how OBB files are delivered. Also fix bug by re-deriving permissions when files are moved. Bug: 25399427 Change-Id: I06f38a24ad7dee5f5099ba81429aef03208e5683 --- sdcard/sdcard.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/sdcard/sdcard.c b/sdcard/sdcard.c index b6bbe7efd..45efe369e 100644 --- a/sdcard/sdcard.c +++ b/sdcard/sdcard.c @@ -507,6 +507,16 @@ static void derive_permissions_locked(struct fuse* fuse, struct node *parent, } } +static void derive_permissions_recursive_locked(struct fuse* fuse, struct node *parent) { + struct node *node; + for (node = parent->child; node; node = node->next) { + derive_permissions_locked(fuse, parent, node); + if (node->child) { + derive_permissions_recursive_locked(fuse, node); + } + } +} + /* Kernel has already enforced everything we returned through * derive_permissions_locked(), so this is used to lock down access * even further, such as enforcing that apps hold sdcard_rw. */ @@ -1145,6 +1155,8 @@ static int handle_rename(struct fuse* fuse, struct fuse_handler* handler, res = rename_node_locked(child_node, new_name, new_actual_name); if (!res) { remove_node_from_parent_locked(child_node); + derive_permissions_locked(fuse, new_parent_node, child_node); + derive_permissions_recursive_locked(fuse, child_node); add_node_to_parent_locked(child_node, new_parent_node); } goto done; @@ -1654,6 +1666,9 @@ static bool read_package_list(struct fuse_global* global) { TRACE("read_package_list: found %zu packages\n", hashmapSize(global->package_to_appid)); + /* Regenerate ownership details using newly loaded mapping */ + derive_permissions_recursive_locked(global->fuse_default, &global->root); + pthread_mutex_unlock(&global->lock); return rc;