From 11477fb633ddaf299f9be01f43aac322056d98dc Mon Sep 17 00:00:00 2001 From: Maxim Dounin Date: Tue, 23 Mar 2021 16:52:23 +0300 Subject: [PATCH] gRPC: fixed handling of padding on DATA frames. The response size check introduced in 39501ce97e29 did not take into account possible padding on DATA frames, resulting in incorrect "upstream sent response body larger than indicated content length" errors if upstream server used padding in responses with known length. Fix is to check the actual size of response buffers produced by the code, similarly to how it is done in other protocols, instead of checking the size of DATA frames. Reported at: http://mailman.nginx.org/pipermail/nginx-devel/2021-March/013907.html --- src/http/modules/ngx_http_grpc_module.c | 35 +++++++++++++++++-------- 1 file changed, 24 insertions(+), 11 deletions(-) diff --git a/src/http/modules/ngx_http_grpc_module.c b/src/http/modules/ngx_http_grpc_module.c index f5bf575c2..53bc54710 100644 --- a/src/http/modules/ngx_http_grpc_module.c +++ b/src/http/modules/ngx_http_grpc_module.c @@ -2074,17 +2074,6 @@ ngx_http_grpc_filter(void *data, ssize_t bytes) return NGX_ERROR; } - if (ctx->length != -1) { - if ((off_t) ctx->rest > ctx->length) { - ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, - "upstream sent response body larger " - "than indicated content length"); - return NGX_ERROR; - } - - ctx->length -= ctx->rest; - } - if (ctx->rest > ctx->recv_window) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "upstream violated stream flow control, " @@ -2450,6 +2439,18 @@ ngx_http_grpc_filter(void *data, ssize_t bytes) b->pos = b->last; buf->last = b->pos; + if (ctx->length != -1) { + + if (buf->last - buf->pos > ctx->length) { + ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, + "upstream sent response body larger " + "than indicated content length"); + return NGX_ERROR; + } + + ctx->length -= buf->last - buf->pos; + } + return NGX_AGAIN; } @@ -2457,6 +2458,18 @@ ngx_http_grpc_filter(void *data, ssize_t bytes) buf->last = b->pos; ctx->rest = ctx->padding; + if (ctx->length != -1) { + + if (buf->last - buf->pos > ctx->length) { + ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, + "upstream sent response body larger " + "than indicated content length"); + return NGX_ERROR; + } + + ctx->length -= buf->last - buf->pos; + } + done: if (ctx->padding) {