[PATCH net v3] net: wwan: t7xx: Fix off-by-one error in t7xx_dpmaif_rx_buf_alloc()

[Jinjie Ruan]

The error path in t7xx_dpmaif_rx_buf_alloc(), free and unmap the already
allocated and mapped skb in a loop, but the loop condition terminates when
the index reaches zero, which fails to free the first allocated skb at
index zero.

Check with i-- so that skb at index 0 is freed as well.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: d642b012df70 ("net: wwan: t7xx: Add data path interface")
Acked-by: Sergey Ryazanov <ryazanov.s.a@xxxxxxxxx>
Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
---
v3:
- Remove suggested-by.
- Use i-- to simplify the fix.
- Add Acked-by.
- Add cc stable.
- Update the commit message.
v2:
- Update the commit title.
- Declare i as signed to avoid the endless loop.
---
 drivers/net/wwan/t7xx/t7xx_hif_dpmaif_rx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wwan/t7xx/t7xx_hif_dpmaif_rx.c b/drivers/net/wwan/t7xx/t7xx_hif_dpmaif_rx.c
index 210d84c67ef9..7a9c09cd4fdc 100644
--- a/drivers/net/wwan/t7xx/t7xx_hif_dpmaif_rx.c
+++ b/drivers/net/wwan/t7xx/t7xx_hif_dpmaif_rx.c
@@ -226,7 +226,7 @@ int t7xx_dpmaif_rx_buf_alloc(struct dpmaif_ctrl *dpmaif_ctrl,
 	return 0;
 
 err_unmap_skbs:
-	while (--i > 0)
+	while (i--)
 		t7xx_unmap_bat_skb(dpmaif_ctrl->dev, bat_req->bat_skb, i);
 
 	return ret;
-- 
2.34.1