[PATCH v3 4.14 1/1] test_firmware: fix the memory leaks with the reqs buffer

[Mirsad Todorovac]

[ commit be37bed754ed90b2655382f93f9724b3c1aae847 upstream ]

Dan Carpenter spotted that test_fw_config->reqs will be leaked if
trigger_batched_requests_store() is called two or more times.
The same appears with trigger_batched_requests_async_store().

This bug wasn't triggered by the tests, but observed by Dan's visual
inspection of the code.

The recommended workaround was to return -EBUSY if test_fw_config->reqs
is already allocated.

Fixes: c92316bf8e94 ("test_firmware: add batched firmware tests")
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Russ Weight <russell.h.weight@xxxxxxxxx>
Cc: Tianfei Zhang <tianfei.zhang@xxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Colin Ian King <colin.i.king@xxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: linux-kselftest@xxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx # v4.14
Suggested-by: Dan Carpenter <error27@xxxxxxxxx>
Suggested-by: Takashi Iwai <tiwai@xxxxxxx>
Link: https://lore.kernel.org/r/20230509084746.48259-2-mirsad.todorovac@xxxxxxxxxxxx
Signed-off-by: Mirsad Todorovac <mirsad.todorovac@xxxxxxxxxxxx>

[ This fix is applied against the 4.14 stable branch. There are no changes to the ]
[ fix in code when compared to the upstread, only the reformatting for backport.  ]

---
v2 -> v3:
 minor clarifications in the versioning for the patchwork. not change to commit.

v1 -> v2:
 removed the Reviewed-by: and Acked-by tags, as this is a slightly different patch and
 those need to be reacquired

 lib/test_firmware.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/lib/test_firmware.c b/lib/test_firmware.c
index 1c5e5246bf10..5318c5e18acf 100644
--- a/lib/test_firmware.c
+++ b/lib/test_firmware.c
@@ -621,6 +621,11 @@ static ssize_t trigger_batched_requests_store(struct device *dev,
 
 	mutex_lock(&test_fw_mutex);
 
+        if (test_fw_config->reqs) {
+                rc = -EBUSY;
+                goto out_bail;
+        }
+
 	test_fw_config->reqs = vzalloc(sizeof(struct test_batched_req) *
 				       test_fw_config->num_requests * 2);
 	if (!test_fw_config->reqs) {
@@ -723,6 +728,11 @@ ssize_t trigger_batched_requests_async_store(struct device *dev,
 
 	mutex_lock(&test_fw_mutex);
 
+        if (test_fw_config->reqs) {
+                rc = -EBUSY;
+                goto out_bail;
+        }
+
 	test_fw_config->reqs = vzalloc(sizeof(struct test_batched_req) *
 				       test_fw_config->num_requests * 2);
 	if (!test_fw_config->reqs) {
-- 
2.34.1