From 3739707c4568f05842c8bf770285328067bd6679 Mon Sep 17 00:00:00 2001
From: Karsten Graul <kgraul@linux.ibm.com>
Date: Mon, 17 Feb 2020 16:24:52 +0100
Subject: [PATCH] net/smc: do not delete lgr from list twice
When 2 callers call smc_lgr_terminate() at the same time
for the same lgr, one gets the lgr_lock and deletes the lgr from the
list and releases the lock. Then the second caller gets the lock and
tries to delete it again.
In smc_lgr_terminate() add a check if the link group lgr is already
deleted from the link group list and prevent to try to delete it a
second time.
And add a check if the lgr is marked as freeing, which means that a
termination is already pending.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/smc/smc_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 8f3c1fced3347..9b92b52952dd4 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -629,7 +629,7 @@ void smc_lgr_terminate(struct smc_link_group *lgr, bool soft)
smc_lgr_list_head(lgr, &lgr_lock);
spin_lock_bh(lgr_lock);
- if (lgr->terminating) {
+ if (list_empty(&lgr->list) || lgr->terminating || lgr->freeing) {
spin_unlock_bh(lgr_lock);
return; /* lgr already terminating */
}
--
2.30.2