staging: echo.c: fix memory leakage

we should check the return value of calling function fir16_create(): a NULL
value means the memory allocation fails.

this patch also cleans up the error handling in function function oslec_create()

Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/echo/echo.c b/drivers/staging/echo/echo.c
index 14dfd91..5882139 100644 (file)
--- a/drivers/staging/echo/echo.c
+++ b/drivers/staging/echo/echo.c
@@ -229,6 +229,7 @@ struct oslec_state *oslec_create(int len, int adaption_mode)
 {
        struct oslec_state *ec;
        int i;
+       const int16_t *history;
 
        ec = kzalloc(sizeof(*ec), GFP_KERNEL);
        if (!ec)
@@ -238,15 +239,22 @@ struct oslec_state *oslec_create(int len, int adaption_mode)
        ec->log2taps = top_bit(len);
        ec->curr_pos = ec->taps - 1;
 
-       for (i = 0; i < 2; i++) {
-               ec->fir_taps16[i] =
-                   kcalloc(ec->taps, sizeof(int16_t), GFP_KERNEL);
-               if (!ec->fir_taps16[i])
-                       goto error_oom;
-       }
+       ec->fir_taps16[0] =
+           kcalloc(ec->taps, sizeof(int16_t), GFP_KERNEL);
+       if (!ec->fir_taps16[0])
+               goto error_oom_0;
+
+       ec->fir_taps16[1] =
+           kcalloc(ec->taps, sizeof(int16_t), GFP_KERNEL);
+       if (!ec->fir_taps16[1])
+               goto error_oom_1;
 
-       fir16_create(&ec->fir_state, ec->fir_taps16[0], ec->taps);
-       fir16_create(&ec->fir_state_bg, ec->fir_taps16[1], ec->taps);
+       history = fir16_create(&ec->fir_state, ec->fir_taps16[0], ec->taps);
+       if (!history)
+               goto error_state;
+       history = fir16_create(&ec->fir_state_bg, ec->fir_taps16[1], ec->taps);
+       if (!history)
+               goto error_state_bg;
 
        for (i = 0; i < 5; i++)
                ec->xvtx[i] = ec->yvtx[i] = ec->xvrx[i] = ec->yvrx[i] = 0;
@@ -256,7 +264,7 @@ struct oslec_state *oslec_create(int len, int adaption_mode)
 
        ec->snapshot = kcalloc(ec->taps, sizeof(int16_t), GFP_KERNEL);
        if (!ec->snapshot)
-               goto error_oom;
+               goto error_snap;
 
        ec->cond_met = 0;
        ec->Pstates = 0;
@@ -269,10 +277,15 @@ struct oslec_state *oslec_create(int len, int adaption_mode)
 
        return ec;
 
-error_oom:
-       for (i = 0; i < 2; i++)
-               kfree(ec->fir_taps16[i]);
-
+error_snap:
+       fir16_free(&ec->fir_state_bg);
+error_state_bg:
+       fir16_free(&ec->fir_state);
+error_state:
+       kfree(ec->fir_taps16[1]);
+error_oom_1:
+       kfree(ec->fir_taps16[0]);
+error_oom_0:
        kfree(ec);
        return NULL;
 }