USB: whci-hcd: Fix potential memory leak in qset_add_urb_sg()

Do not leak memory by updating pointer with potentially
NULL realloc return value.

By the way remove unused local variable:
	struct whc_page_list_entry *entry;
More precisely, it was used to increment uninitialized value within one of cycles.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 7 insertions, 4 deletions

diff --git a/drivers/usb/host/whci/qset.c b/drivers/usb/host/whci/qset.c
index 76083ae92138..dc31c425ce01 100644
--- a/drivers/usb/host/whci/qset.c
+++ b/drivers/usb/host/whci/qset.c
@@ -436,7 +436,7 @@ static int qset_add_urb_sg(struct whc *whc, struct whc_qset *qset, struct urb *u
         int i;
         int ntds = 0;
         struct whc_std *std = NULL;
-        struct whc_page_list_entry *entry;
+        struct whc_page_list_entry *new_pl_virt;
         dma_addr_t prev_end = 0;
         size_t pl_len;
         int p = 0;
@@ -508,12 +508,15 @@ static int qset_add_urb_sg(struct whc *whc, struct whc_qset *qset, struct urb *u
 
                         pl_len = std->num_pointers * sizeof(struct whc_page_list_entry);
 
-                        std->pl_virt = krealloc(std->pl_virt, pl_len, mem_flags);
-                        if (std->pl_virt == NULL) {
+                        new_pl_virt = krealloc(std->pl_virt, pl_len, mem_flags);
+                        if (new_pl_virt == NULL) {
+                                kfree(std->pl_virt);
+                                std->pl_virt = NULL;
                                 return -ENOMEM;
                         }
+                        std->pl_virt = new_pl_virt;
 
-                        for (;p < std->num_pointers; p++, entry++) {
+                        for (;p < std->num_pointers; p++) {
                                 std->pl_virt[p].buf_ptr = cpu_to_le64(dma_addr);
                                 dma_addr = (dma_addr + WHCI_PAGE_SIZE) & ~(WHCI_PAGE_SIZE-1);
                         }