[PATCH] net: stmmac: free RX resources when TX allocation fails

[PATCH] net: stmmac: free RX resources when TX allocation fails

[Wentao Liang]

alloc_dma_rx_desc_resources() unwinds the RX queues when the RX
allocation itself fails, and alloc_dma_tx_desc_resources() unwinds the
TX queues when the TX allocation fails.  But when the RX allocation
succeeds and the TX allocation then fails, the RX queues that were
already set up are left behind.  stmmac_setup_dma_desc() only frees the
dma_conf on this path, so the RX DMA rings, page pools and socket
buffers are leaked.

Release the RX queues from alloc_dma_desc_resources() when the TX
allocation fails, before the caller drops the partially populated
dma_conf.

Fixes: ba39b344e924 ("net: ethernet: stmicro: stmmac: generate stmmac dma conf before open")
Cc: stable@vger.kernel.org
Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 9ded31150fbe..049d85b3e25f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2446,6 +2446,8 @@ static int alloc_dma_desc_resources(struct stmmac_priv *priv,
 		return ret;
 
 	ret = alloc_dma_tx_desc_resources(priv, dma_conf);
+	if (ret)
+		free_dma_rx_desc_resources(priv, dma_conf);
 
 	return ret;
 }
-- 
2.34.1

Re: [PATCH] net: stmmac: free RX resources when TX allocation fails

[netdev-bot+sinfo]

Hi!

This is an automated message. This series looks like a fix, but its
commit messages seem to be missing some information:

 - How the issue was discovered, e.g. hit in production, hit during
   development, syzbot report, manual code inspection, LLM or static
   analysis tool scan.

 - Whether the issue was actually triggered, or is only theoretical
   (e.g. found by code inspection). If it was triggered please include
   the symptoms, like the stack trace or error messages.

 - What hardware the change was tested on. For driver fixes please
   mention the device (and if relevant firmware version) used for
   testing, or say that the change was not tested on real hardware.

Please do not repost the series just to address the above. Instead,
reply to this email with the missing information, so that reviewers
can take it into account. If the series needs another revision for
other reasons, please include the information in the commit messages
then.

The evaluation is done by an LLM so it may be wrong, if you think
that is the case please reply and explain.