fs_mgr: overlayfs: requires override_creds patch for 4.4+ kernels (taimen)
The original adb-remount-test.sh when certifying kernels allowed a
pass on 4.4 kernels because it added new content, and missed a test
for overriding existing content. When the test was added to confirm
APEX control of libc.so, it serendipitously added a check for
overriding existing content, which the 4.4 kernel did not allow to
pass. Update the tests and documentation to reflect this new state
of affairs.
Summary: 4.4 kernel overlayfs driver worked partially without the
patch for override_creds.
Test: adb-remount-test.sh
Bug: 126256072
Change-Id: I979ea59a12bc0b9926826b9b09a7893ab3b9ee7f
diff --git a/fs_mgr/README.overlayfs.md b/fs_mgr/README.overlayfs.md
index 2aac260..f89e598 100644
--- a/fs_mgr/README.overlayfs.md
+++ b/fs_mgr/README.overlayfs.md
@@ -94,7 +94,7 @@
and thus free dynamic partition space.
- Kernel must have CONFIG_OVERLAY_FS=y and will need to be patched
with "*overlayfs: override_creds=off option bypass creator_cred*"
- if kernel is higher than 4.6.
+ if kernel is 4.4 or higher.
The patch is available on the upstream mailing list and the latest as of
Feb 8 2019 is https://lore.kernel.org/patchwork/patch/1009299/.
This patch adds an override_creds _mount_ option to overlayfs that
diff --git a/fs_mgr/fs_mgr_overlayfs.cpp b/fs_mgr/fs_mgr_overlayfs.cpp
index 3d5062c..40da36d 100644
--- a/fs_mgr/fs_mgr_overlayfs.cpp
+++ b/fs_mgr/fs_mgr_overlayfs.cpp
@@ -1031,7 +1031,7 @@
if (major > 4) {
return OverlayfsValidResult::kNotSupported;
}
- if (minor > 6) {
+ if (minor > 3) {
return OverlayfsValidResult::kNotSupported;
}
return OverlayfsValidResult::kOk;
diff --git a/fs_mgr/tests/adb-remount-test.sh b/fs_mgr/tests/adb-remount-test.sh
index 8a1b6d6..fd53ed4 100755
--- a/fs_mgr/tests/adb-remount-test.sh
+++ b/fs_mgr/tests/adb-remount-test.sh
@@ -577,20 +577,17 @@
) ||
overlayfs_supported=false
if ${overlayfs_supported}; then
- case `adb_sh uname -r </dev/null` in
- 4.[6789].* | 4.[1-9][0-9]* | [56789].*)
- adb_su ls /sys/module/overlay/parameters/override_creds </dev/null >/dev/null &&
- echo "${GREEN}[ OK ]${NORMAL} overlay module supports override_creds" >&2 ||
- (
- echo "${ORANGE}[ WARNING ]${NORMAL} overlay module does not support override_creds" >&2 &&
- false
- ) ||
+ adb_su ls /sys/module/overlay/parameters/override_creds </dev/null >/dev/null &&
+ echo "${GREEN}[ OK ]${NORMAL} overlay module supports override_creds" >&2 ||
+ case `adb_sh uname -r </dev/null` in
+ 4.[456789].* | 4.[1-9][0-9]* | [56789].*)
+ echo "${ORANGE}[ WARNING ]${NORMAL} overlay module does not support override_creds" >&2 &&
overlayfs_supported=false
- ;;
- *)
- echo "${GREEN}[ OK ]${NORMAL} overlay module uses callers creds" >&2
- ;;
- esac
+ ;;
+ *)
+ echo "${GREEN}[ OK ]${NORMAL} overlay module uses caller's creds" >&2
+ ;;
+ esac
fi
adb_root ||