From: michi <michi+ngircd@dataswamp.org>
Date: Tue, 14 Apr 2020 15:41:52 +0000 (+0200)
Subject: Fix recursion bug on write error
X-Git-Tag: rel-26-rc1~33
X-Git-Url: https://arthur.barton.de/cgi-bin/gitweb.cgi?a=commitdiff_plain;ds=sidebyside;h=04de1423eb26da60c192d343a7e7a6bcda2aca37;p=ngircd-alex.git

Fix recursion bug on write error

Depending on the stack size, too many clients on the same channel
quitting at the same time would trigger a crash due to too many
recursive calls to Conn_Close().
---

diff --git a/src/ngircd/conn.c b/src/ngircd/conn.c
index e14e6c08..92d9939a 100644
--- a/src/ngircd/conn.c
+++ b/src/ngircd/conn.c
@@ -1272,6 +1272,9 @@ Handle_Write( CONN_ID Idx )
 		if (errno == EAGAIN || errno == EINTR)
 			return true;
 
+		/* Log write errors but do not close the connection yet.
+		 * Calling Conn_Close() now could result in too many recursive calls.
+		 */
 		if (!Conn_OPTION_ISSET(&My_Connections[Idx], CONN_ISCLOSING))
 			Log(LOG_ERR,
 			    "Write error on connection %d (socket %d): %s!",
@@ -1279,7 +1282,7 @@ Handle_Write( CONN_ID Idx )
 		else
 			LogDebug("Recursive write error on connection %d (socket %d): %s!",
 				 Idx, My_Connections[Idx].sock, strerror(errno));
-		Conn_Close(Idx, "Write error", NULL, false);
+
 		return false;
 	}