From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Dan Carpenter <dan.carpenter@oracle.com>,
Colin King <colin.king@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>, Phil Elwell <phil@raspberrypi.org>,
Jan Kiszka <jan.kiszka@siemens.com>,
Eric Anholt <eric@anholt.net>,
Thor Thayer <tthayer@opensource.altera.com>,
Rafael Gago <rafael.gago@gmail.com>,
David Lechner <david@lechnology.com>,
linux-serial@vger.kernel.org, kernel-janitors@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH][serial-next] serial: 8250: don't dereference em485 until it has been null checked
Date: Tue, 29 Aug 2017 23:22:04 +0300 [thread overview]
Message-ID: <1504038124.25945.155.camel@linux.intel.com> (raw)
In-Reply-To: <20170829200411.wbqdsihcnhpg2gmr@mwanda>
On Tue, 2017-08-29 at 23:04 +0300, Dan Carpenter wrote:
> On Tue, Aug 29, 2017 at 05:58:15PM +0100, Colin King wrote:
> > From: Colin Ian King <colin.king@canonical.com>
> >
> > Currently, the pointer em485 is dereferenced to get p and then later
> > em485 is checked to see if it is null before calling __start_tx. In
> > the case where em485 is null, we get a null pointer dereference. Fix
> > this by moving the deference and the associated spinlock/unlocks on
> > p to the code block where em485 is known to be not null.
> >
> > Detected by CoverityScan, CID#14555001 ("Dereference before null
> > check")
> >
> > Fixes 6e0a5de2136b ("serial: 8250: Use hrtimers for rs485 delays")
>
> I don't understand which tree this commit is from. I have it fetched
> but when I do a git log on drivers/tty/serial/8250/8250_port.c then I
> don't see it. I have today's linux-next.
I see it, though I have tty-next as well.
> I'm pretty sure "t" isn't ever NULL.
(I'm pretty sure there is a false positive, though code would be cleaned
to avoid such reports)
--
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy
prev parent reply other threads:[~2017-08-29 20:22 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-29 16:58 [PATCH][serial-next] serial: 8250: don't dereference em485 until it has been null checked Colin King
2017-08-29 19:57 ` Andy Shevchenko
2017-08-29 20:04 ` Dan Carpenter
2017-08-29 20:22 ` Andy Shevchenko [this message]
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