qede: avoid uninitialized entries in coal_entry array

commit fc83465afdea830a540ad8b57d0f96f0389fd5d0 upstream.

Even after commit 6619a08d4a6f ("qede: fix interrupt coalescing
configuration"), some entries of the coal_entry array may theoretically
be used uninitialized:

 1. qede_alloc_fp_array() allocates QEDE_MAX_RSS_CNT entries for
    coal_entry. The initial allocation uses kcalloc, so everything is
    initialized.
 2. The user sets a small number of queues (ethtool -L).
    coal_entry is reallocated for the actual small number of queues.
 3. The user sets a bigger number of queues.
    coal_entry is reallocated bigger. The added entries are not
    necessarily initialized.

In practice, the reallocations will actually keep using the originally
allocated region of memory, but we should not rely on it.

The reallocation is unnecessary. coal_entry can always have
QEDE_MAX_RSS_CNT entries.

Fixes: 6619a08d4a6f ("qede: fix interrupt coalescing configuration")
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Nacked-by: Manish Chopra <manishc@marvell.com>
Acked-by: Manish Chopra <manishc@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/qlogic/qede/qede_main.c b/drivers/net/ethernet/qlogic/qede/qede_main.c
index af39513db1ba30ad715c60ce12f62b4c32df4926..89d64a5a4951a58d209d922a1af6d545859848df 100644 (file)
--- a/drivers/net/ethernet/qlogic/qede/qede_main.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_main.c
@@ -960,7 +960,6 @@ static int qede_alloc_fp_array(struct qede_dev *edev)
 {
        u8 fp_combined, fp_rx = edev->fp_num_rx;
        struct qede_fastpath *fp;
-       void *mem;
        int i;
 
        edev->fp_array = kcalloc(QEDE_QUEUE_CNT(edev),
@@ -971,20 +970,14 @@ static int qede_alloc_fp_array(struct qede_dev *edev)
        }
 
        if (!edev->coal_entry) {
-               mem = kcalloc(QEDE_MAX_RSS_CNT(edev),
-                             sizeof(*edev->coal_entry), GFP_KERNEL);
-       } else {
-               mem = krealloc(edev->coal_entry,
-                              QEDE_QUEUE_CNT(edev) * sizeof(*edev->coal_entry),
-                              GFP_KERNEL);
-       }
-
-       if (!mem) {
-               DP_ERR(edev, "coalesce entry allocation failed\n");
-               kfree(edev->coal_entry);
-               goto err;
+               edev->coal_entry = kcalloc(QEDE_MAX_RSS_CNT(edev),
+                                          sizeof(*edev->coal_entry),
+                                          GFP_KERNEL);
+               if (!edev->coal_entry) {
+                       DP_ERR(edev, "coalesce entry allocation failed\n");
+                       goto err;
+               }
        }
-       edev->coal_entry = mem;
 
        fp_combined = QEDE_QUEUE_CNT(edev) - fp_rx - edev->fp_num_tx;