[PATCH] staging: r8188eu: Fix potential memory leak or NULL dereference

[Larry Finger]

In routine c2h_wk_callback(() following a kmalloc() call, the
error recovery is flawed. If the kmalloc() returns a pointer
that is not NULL, and the following c2h_evt_read() fails, the
code will leak that buffer. If the kmalloc() fails, a NULL
dereference will occur in the following code.

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx>
---
 drivers/staging/r8188eu/core/rtw_cmd.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/r8188eu/core/rtw_cmd.c b/drivers/staging/r8188eu/core/rtw_cmd.c
index c3a9051ca10c..238ae79f4141 100644
--- a/drivers/staging/r8188eu/core/rtw_cmd.c
+++ b/drivers/staging/r8188eu/core/rtw_cmd.c
@@ -1908,8 +1908,12 @@ static void c2h_wk_callback(struct work_struct *work)
 			c2h_evt = kmalloc(16, GFP_KERNEL);
 			if (c2h_evt) {
 				/* This C2H event is not read, read & clear now */
-				if (c2h_evt_read(adapter, (u8 *)c2h_evt) != _SUCCESS)
+				if (c2h_evt_read(adapter, (u8 *)c2h_evt) != _SUCCESS) {
+					kfree(c2h_evt);
 					continue;
+				}
+			} else {
+				return;
 			}
 		}
 
-- 
2.32.0