From: Artem Boldariev <artem@boldariev.com>
Date: Thu, 6 May 2021 12:14:04 +0000 (+0300)
Subject: Fix crash in client side DoH code
X-Git-Tag: v9.17.13~9^2~1
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a9e97f28b77340d4fb14e22cd5ad3088ecec8022;p=thirdparty%2Fbind9.git

Fix crash in client side DoH code

This commit fixes a situation when a cstream object could get unlinked
from the list as a result of a cstream->read_cb call. Thus, unlinking
it after the call could crash the program.
---

diff --git a/lib/isc/netmgr/http.c b/lib/isc/netmgr/http.c
index c2e403a5d02..9dc5e4d5c3c 100644
--- a/lib/isc/netmgr/http.c
+++ b/lib/isc/netmgr/http.c
@@ -528,10 +528,10 @@ call_unlink_cstream_readcb(http_cstream_t *cstream,
 			   isc_result_t result) {
 	REQUIRE(VALID_HTTP2_SESSION(session));
 	REQUIRE(cstream != NULL);
+	ISC_LIST_UNLINK(session->cstreams, cstream, link);
 	cstream->read_cb(session->handle, result,
 			 &(isc_region_t){ cstream->rbuf, cstream->rbufsize },
 			 cstream->read_cbarg);
-	ISC_LIST_UNLINK(session->cstreams, cstream, link);
 	put_http_cstream(session->mctx, cstream);
 }