From: Meelis Roos <mroos@linux.ee>
To: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Linux Kernel list <linux-kernel@vger.kernel.org>,
linux-ide@vger.kernel.org, linux-block@vger.kernel.org,
Tejun Heo <tj@kernel.org>, Jens Axboe <axboe@kernel.dk>
Subject: Re: UBSAN: Undefined behaviour in block/blk-mq.c:1459:27 with pata_amd
Date: Wed, 18 May 2016 09:59:11 +0300 (EEST) [thread overview]
Message-ID: <alpine.LRH.2.20.1605180958070.21113@math.ut.ee> (raw)
In-Reply-To: <22191628.vH7YQZ1hRO@amdc1976>
> Does the patch below help?
>
> From: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> Subject: [PATCH] blk-mq: fix undefined behaviour in order_to_size()
>
> When this_order variable in blk_mq_init_rq_map() becomes zero
> the code incorrectly decrements the variable and passes the result
> to order_to_size() helper causing undefined behaviour:
>
> UBSAN: Undefined behaviour in block/blk-mq.c:1459:27
> shift exponent 4294967295 is too large for 32-bit type 'unsigned int'
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.6.0-rc6-00072-g33656a1 #22
>
> Fix the code by checking this_order variable for not having the zero
> value first.
>
> Reported-by: Meelis Roos <mroos@linux.ee>
> Fixes: 320ae51feed5 ("blk-mq: new multi-queue block IO queueing mechanism")
> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
It fixes the warning independently of the pata driver - ata_piix
pata_via pata_serverworks pata_macio 3ware were fixed too.
--
Meelis Roos (mroos@linux.ee)
prev parent reply other threads:[~2016-05-18 5:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-12 16:05 UBSAN: Undefined behaviour in block/blk-mq.c:1459:27 with pata_amd Meelis Roos
2016-05-13 15:31 ` Bartlomiej Zolnierkiewicz
2016-05-14 9:05 ` Meelis Roos
2016-05-16 15:55 ` Jens Axboe
2016-05-18 6:59 ` Meelis Roos [this message]
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