From: Vladimir Oltean Date: Sun, 24 Oct 2021 17:17:48 +0000 (+0300) Subject: net: dsa: avoid refcount warnings when ->port_{fdb,mdb}_del returns error X-Git-Tag: v6.1-rc5~2768^2~102^2~9 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=232deb3f9567ce37d99b8616a6c07c1fc0436abf;p=platform%2Fkernel%2Flinux-starfive.git net: dsa: avoid refcount warnings when ->port_{fdb,mdb}_del returns error At present, when either of ds->ops->port_fdb_del() or ds->ops->port_mdb_del() return a non-zero error code, we attempt to save the day and keep the data structure associated with that switchdev object, as the deletion procedure did not complete. However, the way in which we do this is suspicious to the checker in lib/refcount.c, who thinks it is buggy to increment a refcount that became zero, and that this is indicative of a use-after-free. Fixes: 161ca59d39e9 ("net: dsa: reference count the MDB entries at the cross-chip notifier level") Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller --- diff --git a/net/dsa/switch.c b/net/dsa/switch.c index 2b1b21b..8f8ed82 100644 --- a/net/dsa/switch.c +++ b/net/dsa/switch.c @@ -266,7 +266,7 @@ static int dsa_port_do_mdb_del(struct dsa_port *dp, err = ds->ops->port_mdb_del(ds, port, mdb); if (err) { - refcount_inc(&a->refcount); + refcount_set(&a->refcount, 1); return err; } @@ -333,7 +333,7 @@ static int dsa_port_do_fdb_del(struct dsa_port *dp, const unsigned char *addr, err = ds->ops->port_fdb_del(ds, port, addr, vid); if (err) { - refcount_inc(&a->refcount); + refcount_set(&a->refcount, 1); return err; }