changeset 7710:097f578a4a8f

HTTP/2: fixed segfault on DATA frames after 400 errors. If 400 errors were redirected to an upstream server using the error_page directive, DATA frames from the client might cause segmentation fault due to null pointer dereference. The bug had appeared in 6989:2c4dbcd6f2e4 (1.13.0). Fix is to skip such frames in ngx_http_v2_state_read_data() (similarly to 7561:9f1f9d6e056a). With the fix, behaviour of 400 errors in HTTP/2 is now similar to one in HTTP/1.x, that is, nginx doesn't try to read the request body. Note that proxying 400 errors, as well as other early stage errors, to upstream servers might not be a good idea anyway. These errors imply that reading and processing of the request (and the request headers) wasn't complete, and proxying of such incomplete request might lead to various errors. Reported by Chenglong Zhang.
author Maxim Dounin <>
date Wed, 23 Sep 2020 19:50:49 +0300
parents 052ecc68d350
children 526dddf637bb
files src/http/v2/ngx_http_v2.c
diffstat 1 files changed, 7 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/src/http/v2/ngx_http_v2.c
+++ b/src/http/v2/ngx_http_v2.c
@@ -1084,6 +1084,13 @@ ngx_http_v2_state_read_data(ngx_http_v2_
         return ngx_http_v2_state_skip_padded(h2c, pos, end);
+    if (r->headers_in.content_length_n < 0 && !r->headers_in.chunked) {
+        ngx_log_debug0(NGX_LOG_DEBUG_HTTP, h2c->connection->log, 0,
+                       "skipping http2 DATA frame");
+        return ngx_http_v2_state_skip_padded(h2c, pos, end);
+    }
     size = end - pos;
     if (size >= h2c->state.length) {