On Thu 23 Jan 2025 at 14:40, Mattijs Korpershoek <[email protected]> wrote:
> 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") > Signed-off-by: Mattijs Korpershoek <[email protected]> > --- > 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 > 2cd167f80280801618a317a65e93a10e70a0d9ee..dc9aad1633bb7a6d577013bfa0f939343f2e066b > 100644 > --- a/boot/bootmeth_android.c > +++ b/boot/bootmeth_android.c > @@ -407,17 +407,26 @@ 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) { > @@ -427,9 +436,11 @@ 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; > > > -- > 2.47.1 > Reviewed-by: Julien Masson <[email protected]>
