Android/frameworks_base
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Merge "Whitelist file descriptors created through memfd_create."

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This commit is contained in:
Nicolas Geoffray
2019-10-29 15:45:03 +00:00
committed by Gerrit Code Review
parent 00639037d7 813b9e8cb4
commit d10a84cdfe
1 changed files with 14 additions and 0 deletions
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14
core/jni/fd_utils.cpp
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@@ -59,6 +59,10 @@ FileDescriptorWhitelist* FileDescriptorWhitelist::Get() {
return instance_; return instance_;
} }
static bool IsMemfd(const std::string& path) {
return android::base::StartsWith(path, "/memfd:");
}
bool FileDescriptorWhitelist::IsAllowed(const std::string& path) const { bool FileDescriptorWhitelist::IsAllowed(const std::string& path) const {
// Check the static whitelist path. // Check the static whitelist path.
for (const auto& whitelist_path : kPathWhitelist) { for (const auto& whitelist_path : kPathWhitelist) {
@@ -87,6 +91,11 @@ bool FileDescriptorWhitelist::IsAllowed(const std::string& path) const {
return true; return true;
} }
// In-memory files created through memfd_create are allowed.
if (IsMemfd(path)) {
return true;
}
// Whitelist files needed for Runtime Resource Overlay, like these: // Whitelist files needed for Runtime Resource Overlay, like these:
// /system/vendor/overlay/framework-res.apk // /system/vendor/overlay/framework-res.apk
// /system/vendor/overlay-subdir/pg/framework-res.apk // /system/vendor/overlay-subdir/pg/framework-res.apk
@@ -312,6 +321,11 @@ void FileDescriptorInfo::ReopenOrDetach(fail_fn_t fail_fn) const {
return DetachSocket(fail_fn); return DetachSocket(fail_fn);
} }
// Children can directly use in-memory files created through memfd_create.
if (IsMemfd(file_path)) {
return;
}
// NOTE: This might happen if the file was unlinked after being opened. // NOTE: This might happen if the file was unlinked after being opened.
// It's a common pattern in the case of temporary files and the like but // It's a common pattern in the case of temporary files and the like but
// we should not allow such usage from the zygote. // we should not allow such usage from the zygote.