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

From: Mukesh Ojha
Date: Wed Mar 20 2019 - 08:09:54 EST



On 3/19/2019 4:14 AM, 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 <pakki001@xxxxxxx>
---
drivers/thunderbolt/switch.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index cd96994dc094..c05d77073ee7 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -1294,13 +1294,13 @@ 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;
if (sw->uuid)
- return;
+ return 0;
/*
* The newer controllers include fused UUID as part of link
@@ -1323,6 +1323,9 @@ static void tb_switch_set_uuid(struct tb_switch *sw)
}
sw->uuid = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);
+ if (!sw->uuid)
+ return -ENOMEM;
+ return 0;
}

Change looks good to me.

Reviewed-by: Mukesh Ojha <mojha@xxxxxxxxxxxxxx>

but, we should add check for `tb_sw_read ` this as well.


Cheers,
Mukesh


static int tb_switch_add_dma_port(struct tb_switch *sw)
@@ -1372,7 +1375,9 @@ 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);

@@ -1Reviewed-by: Andy Shevchenko<andriy.shevchenko@xxxxxxxxxxxxxxx>422,7 +1427,9 @@ 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) {