From 2edaace575fa1bdfa760ee41d7d7a87efb3586ae Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Tue, 3 May 2022 15:19:49 +0200 Subject: [PATCH] BUG/MINOR: map/cli: protect the backref list during "show map" errors In case of write error in "show map", the backref is detached but the list wasn't locked when this is done. The risk is very low but it may happen that two concurrent "show map" one of which would fail or one "show map" failing while the same entry is being updated could cause a crash. This should be backported to all stable versions. --- src/map.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/src/map.c b/src/map.c index 2a313f481..4c0b45b73 100644 --- a/src/map.c +++ b/src/map.c @@ -332,10 +332,12 @@ static int cli_io_handler_pat_list(struct appctx *appctx) * reference to the last ref_elt being dumped. */ if (appctx->st2 == STAT_ST_LIST) { + HA_SPIN_LOCK(PATREF_LOCK, &appctx->ctx.map.ref->lock); if (!LIST_ISEMPTY(&appctx->ctx.map.bref.users)) { LIST_DELETE(&appctx->ctx.map.bref.users); LIST_INIT(&appctx->ctx.map.bref.users); } + HA_SPIN_UNLOCK(PATREF_LOCK, &appctx->ctx.map.ref->lock); } return 1; }