From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Dan Carpenter <dan.carpenter@linaro.org>
Cc: "Michał Kępień" <kernel@kempniu.pl>,
"Richard Weinberger" <richard@nod.at>,
"Vignesh Raghavendra" <vigneshr@ti.com>,
linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH v2 resend] mtdchar: fix integer overflow in read/write ioctls
Date: Tue, 30 Sep 2025 14:57:19 +0200 [thread overview]
Message-ID: <87qzvogksw.fsf@bootlin.com> (raw)
In-Reply-To: <aNvN4kfJ2ROB353Q@stanley.mountain> (Dan Carpenter's message of "Tue, 30 Sep 2025 15:32:34 +0300")
Hi Dan,
On 30/09/2025 at 15:32:34 +03, Dan Carpenter <dan.carpenter@linaro.org> wrote:
> The "req.start" and "req.len" variables are u64 values that come from the
> user at the start of the function. We mask away the high 32 bits of
> "req.len" so that's capped at U32_MAX but the "req.start" variable can go
> up to U64_MAX which means that the addition can still integer overflow.
>
> Use check_add_overflow() to fix this bug.
>
> Fixes: 095bb6e44eb1 ("mtdchar: add MEMREAD ioctl")
> Fixes: 6420ac0af95d ("mtdchar: prevent unbounded allocation in MEMWRITE ioctl")
> Cc: stable@vger.kernel.org
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
> v2: fix the tags.
> RESEND: I sent this last year but it wasn't applied.
> https://lore.kernel.org/all/Z1ax3K3-zSJExPNV@stanley.mountain/
I don't know why, perhaps it got filtered as SPAM, I don't know, but I'm
sorry about that.
I've just "closed" next, so I'll queue this in a fixes PR on top of
v5.18-rc1.
Thanks,
Miquèl
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next prev parent reply other threads:[~2025-09-30 12:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-30 12:32 [PATCH v2 resend] mtdchar: fix integer overflow in read/write ioctls Dan Carpenter
2025-09-30 12:57 ` Miquel Raynal [this message]
2025-10-22 9:56 ` Miquel Raynal
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