Re: [PATCH] usbip: usbip_host: fix stub_dev lock context imbalance regression

[Greg KH]

On Wed, May 29, 2019 at 01:46:15PM -0600, Shuah Khan wrote:
> Fix the following sparse context imbalance regression introduced in
> a patch that fixed sleeping function called from invalid context bug.
> 
> kbuild test robot reported on:
> 
> tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git  usb-linus
> 
> Regressions in current branch:
> 
> drivers/usb/usbip/stub_dev.c:399:9: sparse: sparse: context imbalance in 'stub_probe' - different lock contexts for basic block
> drivers/usb/usbip/stub_dev.c:418:13: sparse: sparse: context imbalance in 'stub_disconnect' - different lock contexts for basic block
> drivers/usb/usbip/stub_dev.c:464:1-10: second lock on line 476
> 
> Error ids grouped by kconfigs:
> 
> recent_errors
> âââ i386-allmodconfig
> â   âââ drivers-usb-usbip-stub_dev.c:second-lock-on-line
> âââ x86_64-allmodconfig
> â   âââ drivers-usb-usbip-stub_dev.c:sparse:sparse:context-imbalance-in-stub_disconnect-different-lock-contexts-for-basic-block
> â   âââ drivers-usb-usbip-stub_dev.c:sparse:sparse:context-imbalance-in-stub_probe-different-lock-contexts-for-basic-block
> âââ x86_64-allyesconfig
>     âââ drivers-usb-usbip-stub_dev.c:second-lock-on-line
> 
> This is a real problem in an error leg where spin_lock() is called on an
> already held lock.
> 
> Fix the imbalance in stub_probe() and stub_disconnect().
> 
> Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>

I'll go add:

Fixes: 0c9e8b3cad65 ("usbip: usbip_host: fix BUG: sleeping function called from invalid context")
Cc: stable <stable@xxxxxxxxxxxxxxx>

as the patch this fixes was tagged for stable.

thanks,

greg k-h