diff --git a/nbd/server.c b/nbd/server.c index df771fd42f..7d6801b427 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1366,15 +1366,6 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, return -EIO; } - /* Check for sanity in the parameters, part 1. Defer as many - * checks as possible until after reading any NBD_CMD_WRITE - * payload, so we can try and keep the connection alive. */ - if ((request->from + request->len) < request->from) { - error_setg(errp, - "integer overflow detected, you're probably being attacked"); - return -EINVAL; - } - if (request->type == NBD_CMD_READ || request->type == NBD_CMD_WRITE) { if (request->len > NBD_MAX_BUFFER_SIZE) { error_setg(errp, "len (%" PRIu32" ) is larger than max len (%u)", @@ -1399,12 +1390,21 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, request->len); } - /* Sanity checks, part 2. */ - if (request->from + request->len > client->exp->size) { + /* Sanity checks. */ + if (client->exp->nbdflags & NBD_FLAG_READ_ONLY && + (request->type == NBD_CMD_WRITE || + request->type == NBD_CMD_WRITE_ZEROES || + request->type == NBD_CMD_TRIM)) { + error_setg(errp, "Export is read-only"); + return -EROFS; + } + if (request->from > client->exp->size || + request->from + request->len > client->exp->size) { error_setg(errp, "operation past EOF; From: %" PRIu64 ", Len: %" PRIu32 ", Size: %" PRIu64, request->from, request->len, (uint64_t)client->exp->size); - return request->type == NBD_CMD_WRITE ? -ENOSPC : -EINVAL; + return (request->type == NBD_CMD_WRITE || + request->type == NBD_CMD_WRITE_ZEROES) ? -ENOSPC : -EINVAL; } valid_flags = NBD_CMD_FLAG_FUA; if (request->type == NBD_CMD_READ && client->structured_reply) { @@ -1482,12 +1482,6 @@ static coroutine_fn void nbd_trip(void *opaque) break; case NBD_CMD_WRITE: - if (exp->nbdflags & NBD_FLAG_READ_ONLY) { - error_setg(&local_err, "Export is read-only"); - ret = -EROFS; - break; - } - flags = 0; if (request.flags & NBD_CMD_FLAG_FUA) { flags |= BDRV_REQ_FUA; @@ -1500,12 +1494,6 @@ static coroutine_fn void nbd_trip(void *opaque) break; case NBD_CMD_WRITE_ZEROES: - if (exp->nbdflags & NBD_FLAG_READ_ONLY) { - error_setg(&local_err, "Export is read-only"); - ret = -EROFS; - break; - } - flags = 0; if (request.flags & NBD_CMD_FLAG_FUA) { flags |= BDRV_REQ_FUA;