Bug #2822: Segmentation fault on HTTP chunked input - Lighttpd - lighty labs

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Bug #2822

closed

Segmentation fault on HTTP chunked input

Added by AlxT over 6 years ago. Updated over 6 years ago.

Status:

Fixed

Priority:

Normal

Category:

core

Target version:

1.4.46

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Description

Apss like WhatsApp are sending requests with \r\n after header:

POST /chat HTTP/1.1
Host: c.whatsapp.net
User-Agent: Mozilla/5.0 (compatible; WAChat/1.2; +http://www.whatsapp.com/contact)
Transfer-Encoding: chunked

if mod_fastcgi is enabled then we are getting Segmentation fault.
Bug affected versions >= 1.4.44

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Updated by gstrauss over 6 years ago

Target version changed from 1.4.x to 1.4.46

Thanks for the report. Are there any more details you can provide? Do you mean that the header looks like the following?

POST /chat HTTP/1.1\r\n
Host: c.whatsapp.net\r\n
User-Agent: Mozilla/5.0 (compatible; WAChat/1.2; +http://www.whatsapp.com/contact)\r\n
Transfer-Encoding: chunked\r\n
\r\n
\r\n

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Updated by gstrauss over 6 years ago

Ok. I can get this. An assert() is firing and I'll have to look why later tonight.

Program received signal SIGSEGV, Segmentation fault.
connection_handle_read_post_chunked (dst_cq=0x658600, cq=0x6585b0, 
    con=0x657f90, srv=0x646010) at connections-glue.c:128
128                force_assert(c->type == MEM_CHUNK);

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Updated by gstrauss over 6 years ago

This appears to fix it. I'll review some other scenarios later and then will commit a fix.

--- a/src/connections-glue.c
+++ b/src/connections-glue.c
@@ -125,6 +125,7 @@ static handler_t connection_handle_read_post_chunked(server *srv, connection *co
         while (0 == te_chunked) {
             char *p;
             chunk *c = cq->first;
+            if (NULL == c) break;
             force_assert(c->type == MEM_CHUNK);
             p = strchr(c->mem->ptr+c->offset, '\n');
             if (NULL != p) { /* found HTTP chunked header line */

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Updated by gstrauss over 6 years ago

Subject changed from Segmentation fault. fast_cgi to Segmentation fault on HTTP chunked input
Category changed from mod_fastcgi to core
Status changed from New to Patch Pending