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* [PATCH net] octeontx2-pf: Fix potential use after free in otx2_tc_add_flow()
@ 2025-09-23 11:19 Dan Carpenter
  2025-09-23 11:54 ` Vadim Fedorenko
  2025-09-25  9:10 ` patchwork-bot+netdevbpf
  0 siblings, 2 replies; 3+ messages in thread
From: Dan Carpenter @ 2025-09-23 11:19 UTC (permalink / raw)
  To: Subbaraya Sundeep
  Cc: Sunil Goutham, Geetha sowjanya, hariprasad, Bharat Bhushan,
	Andrew Lunn, David S. Miller, Eric Dumazet, Jakub Kicinski,
	Paolo Abeni, netdev, linux-kernel, kernel-janitors

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 <dan.carpenter@linaro.org>
---
 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


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH net] octeontx2-pf: Fix potential use after free in otx2_tc_add_flow()
  2025-09-23 11:19 [PATCH net] octeontx2-pf: Fix potential use after free in otx2_tc_add_flow() Dan Carpenter
@ 2025-09-23 11:54 ` Vadim Fedorenko
  2025-09-25  9:10 ` patchwork-bot+netdevbpf
  1 sibling, 0 replies; 3+ messages in thread
From: Vadim Fedorenko @ 2025-09-23 11:54 UTC (permalink / raw)
  To: Dan Carpenter, Subbaraya Sundeep
  Cc: Sunil Goutham, Geetha sowjanya, hariprasad, Bharat Bhushan,
	Andrew Lunn, David S. Miller, Eric Dumazet, Jakub Kicinski,
	Paolo Abeni, netdev, linux-kernel, kernel-janitors

On 23/09/2025 12:19, Dan Carpenter wrote:
> 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 <dan.carpenter@linaro.org>

Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH net] octeontx2-pf: Fix potential use after free in otx2_tc_add_flow()
  2025-09-23 11:19 [PATCH net] octeontx2-pf: Fix potential use after free in otx2_tc_add_flow() Dan Carpenter
  2025-09-23 11:54 ` Vadim Fedorenko
@ 2025-09-25  9:10 ` patchwork-bot+netdevbpf
  1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2025-09-25  9:10 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: sbhatta, sgoutham, gakula, hkelam, bbhushan2, andrew+netdev,
	davem, edumazet, kuba, pabeni, netdev, linux-kernel,
	kernel-janitors

Hello:

This patch was applied to netdev/net.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Tue, 23 Sep 2025 14:19:11 +0300 you wrote:
> 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 <dan.carpenter@linaro.org>
> 
> [...]

Here is the summary with links:
  - [net] octeontx2-pf: Fix potential use after free in otx2_tc_add_flow()
    https://git.kernel.org/netdev/net/c/d9c70e93ec59

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html



^ permalink raw reply	[flat|nested] 3+ messages in thread

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2025-09-23 11:19 [PATCH net] octeontx2-pf: Fix potential use after free in otx2_tc_add_flow() Dan Carpenter
2025-09-23 11:54 ` Vadim Fedorenko
2025-09-25  9:10 ` patchwork-bot+netdevbpf

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