target/user: Don't free expired command when time out

Which would result in NPE after when userspace connected again.

Expired command would be freed either when handling command(by userspace),
or when device was tearing down

Reviewed-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Sheng Yang <sheng@yasker.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Orabug: 25395066
(cherry picked from commit b25c786399367b9a8bd955d8496669d019409bec)
Signed-off-by: Kyle Fortin <kyle.fortin@oracle.com>
Reviewed-by: Shan Hai <shan.hai@oracle.com>

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 51ba5c370816958a1a07c96d91b11707dca8b070..e0e98c66323c63cb088fec0b743c4c958886edb5 100644 (file)
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -558,9 +558,13 @@ static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *
        struct tcmu_dev *udev = cmd->tcmu_dev;
 
        if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
-               /* cmd has been completed already from timeout, just reclaim data
-                  ring space */
+               /*
+                * cmd has been completed already from timeout, just reclaim
+                * data ring space and free cmd
+                */
                free_data_area(udev, cmd);
+
+               kmem_cache_free(tcmu_cmd_cache, cmd);
                return;
        }
 
@@ -974,18 +978,20 @@ err_vzalloc:
        return ret;
 }
 
-static int tcmu_check_pending_cmd(int id, void *p, void *data)
+static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
 {
-       struct tcmu_cmd *cmd = p;
-
-       if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags))
+       if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
+               kmem_cache_free(tcmu_cmd_cache, cmd);
                return 0;
+       }
        return -EINVAL;
 }
 
 static void tcmu_free_device(struct se_device *dev)
 {
        struct tcmu_dev *udev = TCMU_DEV(dev);
+       struct tcmu_cmd *cmd;
+       bool all_expired = true;
        int i;
 
        del_timer_sync(&udev->timeout);
@@ -994,10 +1000,13 @@ static void tcmu_free_device(struct se_device *dev)
 
        /* Upper layer should drain all requests before calling this */
        spin_lock_irq(&udev->commands_lock);
-       i = idr_for_each(&udev->commands, tcmu_check_pending_cmd, NULL);
+       idr_for_each_entry(&udev->commands, cmd, i) {
+               if (tcmu_check_and_free_pending_cmd(cmd) != 0)
+                       all_expired = false;
+       }
        idr_destroy(&udev->commands);
        spin_unlock_irq(&udev->commands_lock);
-       WARN_ON(i);
+       WARN_ON(!all_expired);
 
        /* Device was configured */
        if (udev->uio_info.uio_dev) {