Re: [PATCH v2] thunderbolt: Fix to check for kmemdup failure

[Mukesh Ojha]

On 3/20/2019 9:27 PM, Aditya Pakki wrote:

Memory allocated via kmemdup might fail and return a NULL pointer.
This patch adds a check on the return value of kmemdup and passes the
error upstream.

Signed-off-by: Aditya Pakki <pakki...@umn.edu>

---
v1: Missed check on tb_sw_read, suggested by Mukesh
---
  drivers/thunderbolt/switch.c | 22 ++++++++++++++++------
  1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index cd96994dc094..504365d46827 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -1294,13 +1294,14 @@ int tb_switch_configure(struct tb_switch *sw)
        return tb_plug_events_active(sw, true);
  }

-static void tb_switch_set_uuid(struct tb_switch *sw)

+static int tb_switch_set_uuid(struct tb_switch *sw)
  {
        u32 uuid[4];
-       int cap;
+       int cap, ret;

+ ret = 0;

        if (sw->uuid)
-               return;
+               return ret;
  y
        /*
         * The newer controllers include fused UUID as part of link
@@ -1308,7 +1309,9 @@ static void tb_switch_set_uuid(struct tb_switch *sw)
         */
        cap = tb_switch_find_vse_cap(sw, TB_VSE_CAP_LINK_CONTROLLER);
        if (cap > 0) {
-               tb_sw_read(sw, uuid, TB_CFG_SWITCH, cap + 3, 4);
+               ret = tb_sw_read(sw, uuid, TB_CFG_SWITCH, cap + 3, 4);
+               if (ret)
+                       return ret;
        } else {
                /*
                 * ICM generates UUID based on UID and fills the upper
@@ -1323,6 +1326,9 @@ static void tb_switch_set_uuid(struct tb_switch *sw)
        }

sw->uuid = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);

+       if (!sw->uuid)
+               ret = -ENOMEM;
+       return ret;
  }

Thanks for doing the change.

Reviewed-by: Mukesh Ojha <mo...@codeaurora.org>


-Mukesh

static int tb_switch_add_dma_port(struct tb_switch *sw)

@@ -1372,7 +1378,9 @@ static int tb_switch_add_dma_port(struct tb_switch *sw)

if (status) {

                tb_sw_info(sw, "switch flash authentication failed\n");
-               tb_switch_set_uuid(sw);
+               ret = tb_switch_set_uuid(sw);
+               if (ret)
+                       return ret;
                nvm_set_auth_status(sw, status);
        }

@@ -1422,7 +1430,9 @@ int tb_switch_add(struct tb_switch *sw)

                }
                tb_sw_dbg(sw, "uid: %#llx\n", sw->uid);

- tb_switch_set_uuid(sw);

+               ret = tb_switch_set_uuid(sw);
+               if (ret)
+                       return ret;

for (i = 0; i <= sw->config.max_port_number; i++) {

                        if (sw->ports[i].disabled) {