From 6745cbed6edc06fae7fbc4b360e39c3963d57b13 Mon Sep 17 00:00:00 2001 From: Mattijs Korpershoek Date: Wed, 8 Jan 2025 15:38:42 +0100 Subject: [PATCH] bootstd: android: Allow boot with AVB failures when unlocked When the bootloader is UNLOCKED, it should be possible to boot Android even if AVB reports verification errors [1]. This allows developers to flash modified partitions on userdebug/engineering builds. Developers can do so on unlocked devices with: $ fastboot flash --disable-verity --disable-verification vbmeta vbmeta.img In such case, bootmeth_android refuses to boot. Allow the boot to continue when the device is UNLOCKED and AVB reports verification errors. [1] https://source.android.com/docs/security/features/verifiedboot/boot-flow#unlocked-devices Fixes: 125d9f3306ea ("bootstd: Add a bootmeth for Android") Reviewed-by: Julien Masson Link: https://lore.kernel.org/r/20250108-avb-disable-verif-v2-2-ba7d3b0d5b6a@baylibre.com Signed-off-by: Mattijs Korpershoek --- boot/bootmeth_android.c | 37 ++++++++++++++++++++++++------------- 1 file changed, 24 insertions(+), 13 deletions(-) diff --git a/boot/bootmeth_android.c b/boot/bootmeth_android.c index 4ce89d5bcef..a5a86b29d7f 100644 --- a/boot/bootmeth_android.c +++ b/boot/bootmeth_android.c @@ -450,17 +450,26 @@ static int run_avb_verification(struct bootflow *bflow) AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE, &out_data); - if (result != AVB_SLOT_VERIFY_RESULT_OK) { - printf("Verification failed, reason: %s\n", - str_avb_slot_error(result)); - avb_slot_verify_data_free(out_data); - return log_msg_ret("avb verify", -EIO); - } - - if (unlocked) - boot_state = AVB_ORANGE; - else + if (!unlocked) { + /* When device is locked, we only accept AVB_SLOT_VERIFY_RESULT_OK */ + if (result != AVB_SLOT_VERIFY_RESULT_OK) { + printf("Verification failed, reason: %s\n", + str_avb_slot_error(result)); + avb_slot_verify_data_free(out_data); + return log_msg_ret("avb verify", -EIO); + } boot_state = AVB_GREEN; + } else { + /* When device is unlocked, we also accept verification errors */ + if (result != AVB_SLOT_VERIFY_RESULT_OK && + result != AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION) { + printf("Unlocked verification failed, reason: %s\n", + str_avb_slot_error(result)); + avb_slot_verify_data_free(out_data); + return log_msg_ret("avb verify unlocked", -EIO); + } + boot_state = AVB_ORANGE; + } extra_args = avb_set_state(avb_ops, boot_state); if (extra_args) { @@ -470,9 +479,11 @@ static int run_avb_verification(struct bootflow *bflow) goto free_out_data; } - ret = avb_append_commandline(bflow, out_data->cmdline); - if (ret < 0) - goto free_out_data; + if (result == AVB_SLOT_VERIFY_RESULT_OK) { + ret = avb_append_commandline(bflow, out_data->cmdline); + if (ret < 0) + goto free_out_data; + } return 0; -- 2.39.5