diff mbox series

[net,v2] net: ethernet: ti: am65-cpsw: fix freeing IRQ in am65_cpsw_nuss_remove_tx_chns()

Message ID 20250116-am65-cpsw-fix-tx-irq-free-v2-1-ada49409a45f@kernel.org (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series [net,v2] net: ethernet: ti: am65-cpsw: fix freeing IRQ in am65_cpsw_nuss_remove_tx_chns() | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: jpanis@baylibre.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2025-01-16--15-01 (tests: 886)

Commit Message

Roger Quadros Jan. 16, 2025, 1:54 p.m. UTC
When getting the IRQ we use k3_udma_glue_tx_get_irq() which returns
negative error value on error. So not NULL check is not sufficient
to deteremine if IRQ is valid. Check that IRQ is greater then zero
to ensure it is valid.

There is no issue at probe time but at runtime user can invoke
.set_channels which results in the following call chain.
am65_cpsw_set_channels()
 am65_cpsw_nuss_update_tx_rx_chns()
  am65_cpsw_nuss_remove_tx_chns()
  am65_cpsw_nuss_init_tx_chns()

At this point if am65_cpsw_nuss_init_tx_chns() fails due to
k3_udma_glue_tx_get_irq() then tx_chn->irq will be set to a
negative value.

Then, at subsequent .set_channels with higher channel count we
will attempt to free an invalid IRQ in am65_cpsw_nuss_remove_tx_chns()
leading to a kernel warning.

The issue is present in the original commit that introduced this driver,
although there, am65_cpsw_nuss_update_tx_rx_chns() existed as
am65_cpsw_nuss_update_tx_chns().

Fixes: 93a76530316a ("net: ethernet: ti: introduce am65x/j721e gigabit eth subsystem driver")
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Siddharth Vadapalli <s-vadapalli@ti.com>
---
Changes in v2:
- Fixed typo in commit log k3_udma_glue_rx_get_irq->k3_udma_glue_tx_get_irq
- Added more details to commit log
- Added Reviewed-by tags
- Link to v1: https://lore.kernel.org/r/20250114-am65-cpsw-fix-tx-irq-free-v1-1-b2069e6ed185@kernel.org
---
 drivers/net/ethernet/ti/am65-cpsw-nuss.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)


---
base-commit: 5bc55a333a2f7316b58edc7573e8e893f7acb532
change-id: 20250114-am65-cpsw-fix-tx-irq-free-846ac55ee6e1

Best regards,
diff mbox series

Patch

diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
index 5465bf872734..e1de45fb18ae 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
@@ -2248,7 +2248,7 @@  static void am65_cpsw_nuss_remove_tx_chns(struct am65_cpsw_common *common)
 	for (i = 0; i < common->tx_ch_num; i++) {
 		struct am65_cpsw_tx_chn *tx_chn = &common->tx_chns[i];
 
-		if (tx_chn->irq)
+		if (tx_chn->irq > 0)
 			devm_free_irq(dev, tx_chn->irq, tx_chn);
 
 		netif_napi_del(&tx_chn->napi_tx);