kernel: throne_tracker: avoid cross-fs traversal using s_magic check (#2633)

Skip directories that does NOT have the same magic as /data/app.
This is to avoid scanning incfs and any other stacked filesystems.

While this is way dumber, it's way cheaper.
no kern_path(), no missable path_put(), no ref handling.

This supercedes
`throne_tracker: avoid cross fs access
(https://github.com/tiann/KernelSU/pull/2626)`
- upstream
0b6998b474

Signed-off-by: backslashxx
<118538522+backslashxx@users.noreply.github.com>
This commit is contained in:
backslashxx
2025-06-12 14:30:52 +08:00
committed by ShirkNeko
parent 99726a2c4e
commit 9f407a94e3

View File

@@ -214,7 +214,8 @@ void search_manager(const char *path, int depth, struct list_head *uid_data)
int i, stop = 0;
struct list_head data_path_list;
INIT_LIST_HEAD(&data_path_list);
unsigned long data_app_magic = 0;
// Initialize APK cache list
struct apk_path_hash *pos, *n;
list_for_each_entry(pos, &apk_path_hash_list, list) {
@@ -245,6 +246,24 @@ void search_manager(const char *path, int depth, struct list_head *uid_data)
pr_err("Failed to open directory: %s, err: %ld\n", pos->dirpath, PTR_ERR(file));
goto skip_iterate;
}
// grab magic on first folder, which is /data/app
if (!data_app_magic) {
if (file->f_inode->i_sb->s_magic) {
data_app_magic = file->f_inode->i_sb->s_magic;
pr_info("%s: dir: %s got magic! 0x%lx\n", __func__, pos->dirpath, data_app_magic);
} else {
filp_close(file, NULL);
goto skip_iterate;
}
}
if (file->f_inode->i_sb->s_magic != data_app_magic) {
pr_info("%s: skip: %s magic: 0x%lx expected: 0x%lx\n", __func__, pos->dirpath,
file->f_inode->i_sb->s_magic, data_app_magic);
filp_close(file, NULL);
goto skip_iterate;
}
iterate_dir(file, &ctx.ctx);
filp_close(file, NULL);