mlx5: use after free in mlx5_cmd_comp_handler()

We can't dereference "ent" after passing it to free_cmd().

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
index 205753a04cfcb22e8904dbe2e3e203d82df32552..40374063c01ecadd862fa40e75729158e1022a42 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
@@ -1113,7 +1113,13 @@ void mlx5_cmd_comp_handler(struct mlx5_core_dev *dev, unsigned long vector)
 
        for (i = 0; i < (1 << cmd->log_sz); i++) {
                if (test_bit(i, &vector)) {
+                       struct semaphore *sem;
+
                        ent = cmd->ent_arr[i];
+                       if (ent->page_queue)
+                               sem = &cmd->pages_sem;
+                       else
+                               sem = &cmd->sem;
                        ktime_get_ts(&ent->ts2);
                        memcpy(ent->out->first.data, ent->lay->out, sizeof(ent->lay->out));
                        dump_command(dev, ent, 0);
@@ -1136,10 +1142,7 @@ void mlx5_cmd_comp_handler(struct mlx5_core_dev *dev, unsigned long vector)
                        } else {
                                complete(&ent->done);
                        }
-                       if (ent->page_queue)
-                               up(&cmd->pages_sem);
-                       else
-                               up(&cmd->sem);
+                       up(sem);
                }
        }
 }