mfd: pcf50633-adc: Fix potential memleak in pcf50633_adc_async_read()

`req` is allocated in pcf50633_adc_async_read(), but
adc_enqueue_request() could fail to insert the `req` into queue.
We need to check the return value and free it in the case of failure.

Fixes: 08c3e06a5eb2 ("mfd: PCF50633 adc driver")
Signed-off-by: Qiheng Lin <linqiheng@huawei.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20221208061555.8776-1-linqiheng@huawei.com

diff --git a/drivers/mfd/pcf50633-adc.c b/drivers/mfd/pcf50633-adc.c
index 5cd653e615125a2631e9370686389a6c603265f6..191b1bc6141c2fa4f2526a6b847d836f0b664664 100644 (file)
--- a/drivers/mfd/pcf50633-adc.c
+++ b/drivers/mfd/pcf50633-adc.c
@@ -136,6 +136,7 @@ int pcf50633_adc_async_read(struct pcf50633 *pcf, int mux, int avg,
                             void *callback_param)
 {
        struct pcf50633_adc_request *req;
+       int ret;
 
        /* req is freed when the result is ready, in interrupt handler */
        req = kmalloc(sizeof(*req), GFP_KERNEL);
@@ -147,7 +148,11 @@ int pcf50633_adc_async_read(struct pcf50633 *pcf, int mux, int avg,
        req->callback = callback;
        req->callback_param = callback_param;
 
-       return adc_enqueue_request(pcf, req);
+       ret = adc_enqueue_request(pcf, req);
+       if (ret)
+               kfree(req);
+
+       return ret;
 }
 EXPORT_SYMBOL_GPL(pcf50633_adc_async_read);