[PATCH] net: netcp: Fix crash in error path when DMA channel open fails

[Nishanth Menon <nm@ti.com>]

When knav_dma_open_channel() fails in netcp_setup_navigator_resources(),
the rx_channel field is set to an ERR_PTR value. Later, when
netcp_free_navigator_resources() is called in the error path, it attempts
to close this invalid channel pointer, causing a crash.

Add a check for ERR values to handle the failure scenario.

Fixes: 84640e27f230 ("net: netcp: Add Keystone NetCP core driver")
Signed-off-by: Nishanth Menon <nm@ti.com>
---

Seen on kci log for k2hk: https://dashboard.kernelci.org/log-viewer?itemId=ti%3A2eb55ed935eb42c292e02f59&org=ti&type=test&url=http%3A%2F%2Ffiles.kernelci.org%2F%2Fti%2Fmainline%2Fmaster%2Fv6.17-rc7-59-gbf40f4b87761%2Farm%2Fmulti_v7_defconfig%2BCONFIG_EFI%3Dy%2BCONFIG_ARM_LPAE%3Dy%2Bdebug%2Bkselftest%2Btinyconfig%2Fgcc-12%2Fbaseline-nfs-boot.nfs-k2hk-evm.txt.gz

 drivers/net/ethernet/ti/netcp_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ti/netcp_core.c b/drivers/net/ethernet/ti/netcp_core.c
index 857820657bac..4ff17fd6caae 100644
--- a/drivers/net/ethernet/ti/netcp_core.c
+++ b/drivers/net/ethernet/ti/netcp_core.c
@@ -1549,7 +1549,7 @@ static void netcp_free_navigator_resources(struct netcp_intf *netcp)
 {
 	int i;
 
-	if (netcp->rx_channel) {
+	if (!IS_ERR(netcp->rx_channel)) {
 		knav_dma_close_channel(netcp->rx_channel);
 		netcp->rx_channel = NULL;
 	}
-- 
2.47.0