[PATCH net] octeontx2-pf: Fix potential use after free in otx2_tc_add_flow()
From: Dan Carpenter <hidden>
Date: 2025-09-23 11:19:17
Also in:
kernel-janitors, lkml
Subsystem:
marvell octeontx2 physical function driver, networking drivers, the rest · Maintainers:
Sunil Goutham, Geetha sowjanya, Ratheesh Kannoth, Subbaraya Sundeep, Bharat Bhushan, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
This code calls kfree_rcu(new_node, rcu) and then dereferences "new_node"
and then dereferences it on the next line. Two lines later, we take
a mutex so I don't think this is an RCU safe region. Re-order it to do
the dereferences before queuing up the free.
Fixes: 68fbff68dbea ("octeontx2-pf: Add police action for TC flower")
Signed-off-by: Dan Carpenter <redacted>
---
drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
index 5f80b23c5335..26a08d2cfbb1 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_tc.c
@@ -1326,7 +1326,6 @@ static int otx2_tc_add_flow(struct otx2_nic *nic,
free_leaf:
otx2_tc_del_from_flow_list(flow_cfg, new_node);
- kfree_rcu(new_node, rcu);
if (new_node->is_act_police) {
mutex_lock(&nic->mbox.lock);
@@ -1346,6 +1345,7 @@ static int otx2_tc_add_flow(struct otx2_nic *nic,
mutex_unlock(&nic->mbox.lock);
}
+ kfree_rcu(new_node, rcu);
return rc;
}
--
2.51.0