From: Willy Tarreau <w@1wt.eu>
Date: Thu, 18 Aug 2022 16:04:37 +0000 (+0200)
Subject: BUG/MEDIUM: cli: always reset the service context between commands
X-Git-Tag: v2.7-dev4~16
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1addf8b777c69b905591634e492893a2a9233d50;p=thirdparty%2Fhaproxy.git

BUG/MEDIUM: cli: always reset the service context between commands

Erwan Le Goas reported that chaining certain commands on the CLI would
systematically crash the process; for example, "show version; show sess".
This happened since the conversion of cli context to appctx->svcctx,
because if applet_reserve_svcctx() is called a first time for a tiny
context, it's allocated in-situ, and later a keyword that wants a
larger one will see that it's not null and will reuse it and will
overwrite the end of the first one's context.

What is missing is a reset of the svcctx when looping back to
CLI_ST_GETREQ.

This needs to be backported to 2.6, and relies on previous commit
"MINOR: applet: add a function to reset the svcctx of an applet".
---

diff --git a/src/cli.c b/src/cli.c
index c2ca84de13..320bab4c7d 100644
--- a/src/cli.c
+++ b/src/cli.c
@@ -896,6 +896,7 @@ static void cli_io_handler(struct appctx *appctx)
 		if (appctx->st0 == CLI_ST_INIT) {
 			/* reset severity to default at init */
 			appctx->cli_severity_output = bind_conf->severity_output;
+			applet_reset_svcctx(appctx);
 			appctx->st0 = CLI_ST_GETREQ;
 			appctx->cli_level = bind_conf->level;
 		}
@@ -1106,8 +1107,10 @@ static void cli_io_handler(struct appctx *appctx)
 						prompt = "\n";
 				}
 
-				if (applet_putstr(appctx, prompt) != -1)
+				if (applet_putstr(appctx, prompt) != -1) {
+					applet_reset_svcctx(appctx);
 					appctx->st0 = CLI_ST_GETREQ;
+				}
 			}
 
 			/* If the output functions are still there, it means they require more room. */
@@ -1128,6 +1131,7 @@ static void cli_io_handler(struct appctx *appctx)
 			}
 
 			/* switch state back to GETREQ to read next requests */
+			applet_reset_svcctx(appctx);
 			appctx->st0 = CLI_ST_GETREQ;
 			applet_will_consume(appctx);