From: Kevin Wolf Date: Mon, 5 Mar 2018 14:59:35 +0000 (+0100) Subject: block: Fix NULL dereference on empty drive error X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=bfe1a14c180ec44c033be12b9151252ffda69292;p=qemu.git block: Fix NULL dereference on empty drive error blk_error_action() sends a BLOCK_IO_ERROR QMP event which includes the node name of its root node. If the BlockBackend represents an empty drive, there is no root node, so we should not try to access its node name. Make the field optional in the event and include it only when the BlockBackend isn't empty. Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake --- diff --git a/block/block-backend.c b/block/block-backend.c index a775a3dd2f..a4421252f8 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -1615,10 +1615,11 @@ static void send_qmp_error_event(BlockBackend *blk, bool is_read, int error) { IoOperationType optype; + BlockDriverState *bs = blk_bs(blk); optype = is_read ? IO_OPERATION_TYPE_READ : IO_OPERATION_TYPE_WRITE; - qapi_event_send_block_io_error(blk_name(blk), - bdrv_get_node_name(blk_bs(blk)), optype, + qapi_event_send_block_io_error(blk_name(blk), !!bs, + bs ? bdrv_get_node_name(bs) : NULL, optype, action, blk_iostatus_is_enabled(blk), error == ENOSPC, strerror(error), &error_abort); diff --git a/qapi/block-core.json b/qapi/block-core.json index 5c5921bfb7..00475f08d4 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -3676,7 +3676,8 @@ # # @node-name: node name. Note that errors may be reported for the root node # that is directly attached to a guest device rather than for the -# node where the error occurred. (Since: 2.8) +# node where the error occurred. The node name is not present if +# the drive is empty. (Since: 2.8) # # @operation: I/O operation # @@ -3707,7 +3708,8 @@ # ## { 'event': 'BLOCK_IO_ERROR', - 'data': { 'device': 'str', 'node-name': 'str', 'operation': 'IoOperationType', + 'data': { 'device': 'str', '*node-name': 'str', + 'operation': 'IoOperationType', 'action': 'BlockErrorAction', '*nospace': 'bool', 'reason': 'str' } }