linux-kernel - Re: [PATCH v3 1/4] staging: greybus: loopback: Hold per-connection mutex across operations

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 6 Nov 2017 10:17:46 +0100
From:   Johan Hovold <johan@...nel.org>
To:     Bryan O'Donoghue <pure.logic@...us-software.ie>
Cc:     johan@...nel.org, elder@...nel.org, gregkh@...uxfoundation.org,
        devel@...verdev.osuosl.org, keescook@...omium.org,
        linux-kernel@...r.kernel.org, Mitch Tasman <tasman@...flabs.com>,
        greybus-dev@...ts.linaro.org
Subject: Re: [PATCH v3 1/4] staging: greybus: loopback: Hold per-connection
 mutex across operations

On Mon, Nov 06, 2017 at 01:32:19AM +0000, Bryan O'Donoghue wrote:
> Commit d9fb3754ecf8 ("greybus: loopback: Relax locking during loopback
> operations") changes the holding of the per-connection mutex to be less
> restrictive because at the time of that commit per-connection mutexes were
> encapsulated by a per-driver level gb_dev.mutex.
> 
> Commit 8e1d6c336d74 ("greybus: loopback: drop bus aggregate calculation")
> on the other hand subtracts the driver level gb_dev.mutex but neglects to
> move the mutex back to the place it was prior to commit d9fb3754ecf8
> ("greybus: loopback: Relax locking during loopback operations"), as a
> result several members of the per connection struct gb_loopback are racy.
> 
> The solution is restoring the old location of mutex_unlock(&gb->mutex) as
> it was in commit d9fb3754ecf8 ("greybus: loopback: Relax locking during
> loopback operations").
> 
> Fixes: 8e1d6c336d74 ("greybus: loopback: drop bus aggregate calculation")
> 
> Signed-off-by: Bryan O'Donoghue <pure.logic@...us-software.ie>
> Cc: Johan Hovold <johan@...nel.org>
> Cc: Alex Elder <elder@...nel.org>
> Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
> Cc: Mitch Tasman <tasman@...flabs.com>
> Cc: greybus-dev@...ts.linaro.org
> Cc: devel@...verdev.osuosl.org
> Cc: linux-kernel@...r.kernel.org
> ---

This looks like it addresses both my comments on v1 (mutex and error
stats). Thanks for tracking it down.

Reviewed-by: Johan Hovold <johan@...nel.org>

Johan