On Tue, Apr 07, 2020 at 10:54:22AM +0000, Narasimman, Sathish wrote:
> Hi
>
> I think this is False Positive.
>
> In the function btusb_probe the memory allocation is happened and verified for NULL.
> I don't this so checking for NULL evey time is required.
>
> Sample code snip
>
> In function "btusb_probe"
> {
> data = devm_kzalloc(&intf->dev, sizeof(*data), GFP_KERNEL);
> if (!data)
> return -ENOMEM;
> ....
> INIT_WORK(&data->work, btusb_work);
>
> }
This warning is talking about data->isoc, which is checked for NULL in
other places before the call to btusb_find_altsetting(), which doesn't
check for NULL.
-Kees
>
>
> Regards
> Sathish N
>
> -----Original Message-----
> From: coverity-bot <keescook@xxxxxxxxxxxx>
> Sent: Monday, April 6, 2020 9:20 PM
> To: Narasimman, Sathish <sathish.narasimman@xxxxxxxxx>
> Cc: Marcel Holtmann <marcel@xxxxxxxxxxxx>; Tumkur Narayan, Chethan <chethan.tumkur.narayan@xxxxxxxxx>; lkp <lkp@xxxxxxxxx>; Bag, Amit K <amit.k.bag@xxxxxxxxx>; Hsin-Yu Chao <hychao@xxxxxxxxxxxx>; Hedberg, Johan <johan.hedberg@xxxxxxxxx>; Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>; linux-next@xxxxxxxxxxxxxxx
> Subject: Coverity: btusb_work(): Null pointer dereferences
>
> Hello!
>
> This is an experimental automated report about issues detected by Coverity from a scan of next-20200406 as part of the linux-next weekly scan project:
> https://scan.coverity.com/projects/linux-next-weekly-scan
>
> You're getting this email because you were associated with the identified lines of code (noted below) that were touched by recent commits:
>
> baac6276c0a9 ("Bluetooth: btusb: handle mSBC audio over USB Endpoints")
>
> Coverity reported the following:
>
> *** CID 1492498: Null pointer dereferences (FORWARD_NULL)
> /drivers/bluetooth/btusb.c: 1665 in btusb_work()
> 1659 }
> 1660 } else if (data->air_mode == HCI_NOTIFY_ENABLE_SCO_TRANSP) {
> 1661
> 1662 data->usb_alt6_packet_flow = true;
> 1663
> 1664 /* Check if Alt 6 is supported for Transparent audio */
> vvv CID 1492498: Null pointer dereferences (FORWARD_NULL)
> vvv Passing "data" to "btusb_find_altsetting", which dereferences null "data->isoc".
> 1665 if (btusb_find_altsetting(data, 6))
> 1666 new_alts = 6;
> 1667 else
> 1668 bt_dev_err(hdev, "Device does not support ALT setting 6");
> 1669 }
> 1670
>
> If this is a false positive, please let us know so we can mark it as such, or teach the Coverity rules to be smarter. If not, please make sure fixes get into linux-next. :) For patches fixing this, please include these lines (but double-check the "Fixes" first):
>
> Reported-by: coverity-bot <keescook+coverity-bot@xxxxxxxxxxxx>
> Addresses-Coverity-ID: 1492498 ("Null pointer dereferences")
> Fixes: baac6276c0a9 ("Bluetooth: btusb: handle mSBC audio over USB Endpoints")
>
>
> Thanks for your attention!
>
> --
> Coverity-bot
--
Kees Cook
