* [PATCH] ieee802154: mcr20a: read out of bounds in mcr20a_set_channel()
@ 2018-08-29 14:49 Dan Carpenter
[not found] ` <CAJuUDwtjRi0HnR95uaFp4zviSC7Yrs68o8jsK1nY6jWu6909bg@mail.gmail.com>
0 siblings, 1 reply; 2+ messages in thread
From: Dan Carpenter @ 2018-08-29 14:49 UTC (permalink / raw)
To: Xue Liu
Cc: Alexander Aring, Stefan Schmidt, David S. Miller, linux-wpan,
netdev, kernel-janitors
The "channel" variable can be any u8 value. We need to make sure we
don't read outside of the PLL_INT[] or PLL_FRAC[] arrays.
Fixes: 8c6ad9cc5157 ("ieee802154: Add NXP MCR20A IEEE 802.15.4 transceiver driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
This patch is obviously harmless, but it's from static analysis. I'm
pretty sure this is required, but I can't swear.
diff --git a/drivers/net/ieee802154/mcr20a.c b/drivers/net/ieee802154/mcr20a.c
index e428277781ac..4f41d1d3588e 100644
--- a/drivers/net/ieee802154/mcr20a.c
+++ b/drivers/net/ieee802154/mcr20a.c
@@ -512,6 +512,9 @@ mcr20a_set_channel(struct ieee802154_hw *hw, u8 page, u8 channel)
dev_dbg(printdev(lp), "%s\n", __func__);
+ if (channel < 11 || channel - 11 >= ARRAY_SIZE(PLL_INT))
+ return -EINVAL;
+
/* freqency = ((PLL_INT+64) + (PLL_FRAC/65536)) * 32 MHz */
ret = regmap_write(lp->regmap_dar, DAR_PLL_INT0, PLL_INT[channel - 11]);
if (ret)
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] ieee802154: mcr20a: read out of bounds in mcr20a_set_channel()
[not found] ` <CAJuUDwtjRi0HnR95uaFp4zviSC7Yrs68o8jsK1nY6jWu6909bg@mail.gmail.com>
@ 2018-08-30 7:54 ` Dan Carpenter
0 siblings, 0 replies; 2+ messages in thread
From: Dan Carpenter @ 2018-08-30 7:54 UTC (permalink / raw)
To: Xue Liu
Cc: alex. aring, Stefan Schmidt, David S. Miller, linux-wpan - ML,
netdev, kernel-janitors
On Wed, Aug 29, 2018 at 07:50:51PM +0200, Xue Liu wrote:
> Hello Dan,
>
>
> On Wed, 29 Aug 2018 at 16:49, Dan Carpenter <dan.carpenter@oracle.com>
> wrote:
>
> > The "channel" variable can be any u8 value. We need to make sure we
> > don't read outside of the PLL_INT[] or PLL_FRAC[] arrays.
> >
> I think the “channel” variable can not be any u8 value. This values is
> already checked before set_channel function is called.
> https://github.com/torvalds/linux/blob/master/net/ieee802154/nl802154.c#L978
Oh... Hm... I should have reviewed more carefully. This patch isn't
correct. But there may still be a bug. What Smatch is worried about is
the other call tree:
ieee802154_start_req() calls (struct ieee802154_mlme_ops)->start_req
-> mac802154_mlme_start_req()
-> mac802154_dev_set_page_channel()
-> drv_set_channel() calls local->ops->set_channel(&local->hw, page, channel);
-> mcr20a_set_channel()
So maybe we could move the check from nl802154_set_channel() to
drv_set_channel() so channel is checked on both call trees.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 2+ messages in thread
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2018-08-29 14:49 [PATCH] ieee802154: mcr20a: read out of bounds in mcr20a_set_channel() Dan Carpenter
[not found] ` <CAJuUDwtjRi0HnR95uaFp4zviSC7Yrs68o8jsK1nY6jWu6909bg@mail.gmail.com>
2018-08-30 7:54 ` Dan Carpenter
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