[Android] FileProvider: check canonical path for access

[Geoffrey Métais]

vlc-android | branch: master | Geoffrey Métais <geoffrey.metais at gmail.com> | Tue Feb  5 15:00:36 2019 +0100| [86051dd9753a126e454726d9141566d4b1999262] | committer: Geoffrey Métais

FileProvider: check canonical path for access

Thank Shivasurya S <s.shivasurya at gmail.com> for this security report.

> https://code.videolan.org/videolan/vlc-android/commit/86051dd9753a126e454726d9141566d4b1999262
---

 vlc-android/src/org/videolan/vlc/FileProvider.kt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/vlc-android/src/org/videolan/vlc/FileProvider.kt b/vlc-android/src/org/videolan/vlc/FileProvider.kt
index 6d59fcf2d..7b353e732 100644
--- a/vlc-android/src/org/videolan/vlc/FileProvider.kt
+++ b/vlc-android/src/org/videolan/vlc/FileProvider.kt
@@ -27,8 +27,8 @@ class FileProvider : ContentProvider() {
     override fun getType(uri: Uri) = "image/${uri.path?.substringAfterLast('.')}"
 
     override fun openFile(uri: Uri, mode: String?): ParcelFileDescriptor {
-        if (uri.path.startsWith("/data")) throw SecurityException("Illegal access")
         val file = File(uri.path)
+        if (file.canonicalPath.startsWith("/data")) throw SecurityException("Illegal access")
         if (file.exists()) {
             return ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY)
         }