From: Nathan Chancellor <natechancellor@gmail.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Karsten Keil <isdn@linux-pingi.de>,
"David S. Miller" <davem@davemloft.net>,
Nick Desaulniers <ndesaulniers@google.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] isdn: isdnloop: fix pointer dereference bug
Date: Thu, 7 Mar 2019 08:17:42 -0700 [thread overview]
Message-ID: <20190307151742.GC20201@archlinux-ryzen> (raw)
In-Reply-To: <20190307093241.3380715-1-arnd@arndb.de>
On Thu, Mar 07, 2019 at 10:32:07AM +0100, Arnd Bergmann wrote:
> clang has spotted an ancient code bug and warns about it with:
>
> drivers/isdn/isdnloop/isdnloop.c:573:12: error: address of array 'card->rcard' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
>
> This is an array of pointers, so we should check if a specific
> pointer exists in the array before using it, not whether the
> array itself exists.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
> drivers/isdn/isdnloop/isdnloop.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/isdn/isdnloop/isdnloop.c b/drivers/isdn/isdnloop/isdnloop.c
> index f4253d468ae1..755c6bbc9553 100644
> --- a/drivers/isdn/isdnloop/isdnloop.c
> +++ b/drivers/isdn/isdnloop/isdnloop.c
> @@ -570,7 +570,7 @@ isdnloop_atimeout(isdnloop_card *card, int ch)
> char buf[60];
>
> spin_lock_irqsave(&card->isdnloop_lock, flags);
> - if (card->rcard) {
> + if (card->rcard[ch]) {
> isdnloop_fake(card->rcard[ch], "DDIS_I", card->rch[ch] + 1);
> card->rcard[ch]->rcard[card->rch[ch]] = NULL;
> card->rcard[ch] = NULL;
> --
> 2.20.0
>
next prev parent reply other threads:[~2019-03-07 15:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-07 9:32 [PATCH] isdn: isdnloop: fix pointer dereference bug Arnd Bergmann
2019-03-07 15:17 ` Nathan Chancellor [this message]
2019-03-07 17:29 ` David Miller
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