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From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Kees Cook <keescook@chromium.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>,
	Alexey Romanov <avromanov@sberdevices.ru>,
	linux-kernel@vger.kernel.org, Nick Terrell <terrelln@fb.com>,
	Minchan Kim <minchan@kernel.org>,
	Suleiman Souhlal <suleiman@google.com>,
	Nitin Gupta <ngupta@vflare.org>, Jens Axboe <axboe@kernel.dk>,
	Nhat Pham <nphamcs@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-block@vger.kernel.org,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
	linux-next@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: Coverity: zram_recompress(): OVERRUN
Date: Fri, 11 Nov 2022 19:39:31 +0900	[thread overview]
Message-ID: <Y24mY4QFq+3Obnkd@google.com> (raw)
In-Reply-To: <202211101904.7A0B0C3@keescook>

On (22/11/10 19:15), Kees Cook wrote:
> On Fri, Nov 11, 2022 at 09:26:31AM +0900, Sergey Senozhatsky wrote:
> > On (22/11/10 08:47), coverity-bot wrote:
> > > *** CID 1527270:    (OVERRUN)
> > > drivers/block/zram/zram_drv.c:1727 in zram_recompress()
> > > 1721     		zstrm = zcomp_stream_get(zram->comps[prio]);
> > > 1722     		src = kmap_atomic(page);
> > > 1723     		ret = zcomp_compress(zstrm, src, &comp_len_new);
> > > 1724     		kunmap_atomic(src);
> > > 1725
> > > 1726     		if (ret) {
> > > vvv     CID 1527270:    (OVERRUN)
> > > vvv     Overrunning array "zram->comps" of 4 8-byte elements at element index 4 (byte offset 39) using index "prio" (which evaluates to 4).
> > 
> > Hmm... I don't really see how prio can evaluate to 4.
> 
> Yeah, I agree. This looks like a false positive. I'm not sure why
> Coverity triggered for it. Looking at the extended report, it seems to
> not have any idea that prio_max is correctly bounded.
> 
> Sorry for the noise!

No worries!

  reply	other threads:[~2022-11-11 10:39 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-10 16:47 Coverity: zram_recompress(): OVERRUN coverity-bot
2022-11-11  0:26 ` Sergey Senozhatsky
2022-11-11  3:15   ` Kees Cook
2022-11-11 10:39     ` Sergey Senozhatsky [this message]
2022-11-11  0:37 ` Sergey Senozhatsky
2022-11-11  0:42   ` Sergey Senozhatsky
2022-11-11  3:16     ` Kees Cook

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