[PATCH AUTOSEL 5.4 052/130] net: dsa: avoid potential use-after-free error
From: Sasha Levin <sashal@kernel.org>
Date: 2020-12-23 02:59:25
Also in:
lkml, stable
Subsystem:
networking [dsa], networking [general], the rest · Maintainers:
Andrew Lunn, Vladimir Oltean, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Christian Eggers <ceggers@arri.de> [ Upstream commit 30abc9cd9c6bdd44d23fc49a9c2526a86fba4305 ] If dsa_switch_ops::port_txtstamp() returns false, clone will be freed immediately. Shouldn't store a pointer to freed memory. Signed-off-by: Christian Eggers <ceggers@arri.de> Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Tested-by: Vladimir Oltean <olteanv@gmail.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/20201119110906.25558-1-ceggers@arri.de (local) Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- net/dsa/slave.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index f734ce0bcb56e..2b657e88d8017 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c@@ -476,10 +476,10 @@ static void dsa_skb_tx_timestamp(struct dsa_slave_priv *p, if (!clone) return; - DSA_SKB_CB(skb)->clone = clone; - - if (ds->ops->port_txtstamp(ds, p->dp->index, clone, type)) + if (ds->ops->port_txtstamp(ds, p->dp->index, clone, type)) { + DSA_SKB_CB(skb)->clone = clone; return; + } kfree_skb(clone); }
--
2.27.0