Message ID | 20211024171757.3753288-2-vladimir.oltean@nxp.com (mailing list archive) |
---|---|
State | Accepted |
Commit | 232deb3f9567ce37d99b8616a6c07c1fc0436abf |
Delegated to: | Netdev Maintainers |
Headers | show |
Series | Drop rtnl_lock from DSA .port_fdb_{add,del} | expand |
diff --git a/net/dsa/switch.c b/net/dsa/switch.c index 2b1b21bde830..8f8ed8248c2c 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; }
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 <vladimir.oltean@nxp.com> --- v4->v5: patch is new. This is a minor fix and slightly unrelated to the series, but my other patches touch this area and there isn't enough time until the merge window to wait for another net -> net-next merge. I've annotated it with a Fixes: tag and sent it to net-next (also made it the first patch), in the idea that if it could be picked up by AUTOSEL it would be nice, and if not, the problem it fixes isn't so critical anyway. net/dsa/switch.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)