Relax ELF header checks - warn for apps targeting pre-O
Bug: http://b/32581440
Test: bionic-unit-tests --gtest_filter=dl*:Dl*
Change-Id: I2fe356c67eb9665c671758117679a29b207219e4
diff --git a/android-changes-for-ndk-developers.md b/android-changes-for-ndk-developers.md
index 069b004..8925926 100644
--- a/android-changes-for-ndk-developers.md
+++ b/android-changes-for-ndk-developers.md
@@ -221,3 +221,16 @@
*Resolution*: we're aware of one middleware product that introduces these
into your app. The middleware vendor is aware of the problem and has a fix
available.
+
+## Invalid ELF header/section headers (AOSP master)
+
+Android loader now checks for invalid values in ELF header and section headers and fails
+if they are invalid.
+
+*Example error*
+dlopen failed: "/data/data/com.example.bad/lib.so" has unsupported e_shentsize: 0x0 (expected 0x28)
+
+*Resolution*
+Do not use tools that produce invalid/malformed elf-files. Note that using them puts application
+under high risk of being incompatible with future versions of Android.
+
diff --git a/linker/linker_phdr.cpp b/linker/linker_phdr.cpp
index 1b18450..973fcf5 100644
--- a/linker/linker_phdr.cpp
+++ b/linker/linker_phdr.cpp
@@ -248,14 +248,26 @@
}
if (header_.e_shentsize != sizeof(ElfW(Shdr))) {
- DL_ERR("\"%s\" has unsupported e_shentsize: 0x%x (expected 0x%zx)",
- name_.c_str(), header_.e_shentsize, sizeof(ElfW(Shdr)));
- return false;
+ // Fail if app is targeting Android O or above
+ if (get_application_target_sdk_version() >= __ANDROID_API_O__) {
+ DL_ERR_AND_LOG("\"%s\" has unsupported e_shentsize: 0x%x (expected 0x%zx)",
+ name_.c_str(), header_.e_shentsize, sizeof(ElfW(Shdr)));
+ return false;
+ }
+ DL_WARN("\"%s\" has unsupported e_shentsize: 0x%x (expected 0x%zx)",
+ name_.c_str(), header_.e_shentsize, sizeof(ElfW(Shdr)));
+ add_dlwarning(name_.c_str(), "has invalid ELF header");
}
if (header_.e_shstrndx == 0) {
- DL_ERR("\"%s\" has invalid e_shstrndx", name_.c_str());
- return false;
+ // Fail if app is targeting Android O or above
+ if (get_application_target_sdk_version() >= __ANDROID_API_O__) {
+ DL_ERR_AND_LOG("\"%s\" has invalid e_shstrndx", name_.c_str());
+ return false;
+ }
+
+ DL_WARN("\"%s\" has invalid e_shstrndx", name_.c_str());
+ add_dlwarning(name_.c_str(), "has invalid ELF header");
}
return true;