From: Dan Carpenter <dan.carpenter@oracle.com>
To: Denis Efremov <efremov@linux.com>
Cc: Jens Axboe <axboe@kernel.dk>, Arnd Bergmann <arnd@arndb.de>,
linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
linux-kernel-mentees@lists.linuxfoundation.org,
Peilin Ye <yepeilin.cs@gmail.com>
Subject: Re: [Linux-kernel-mentees] [PATCH v2] block/floppy: Prevent kernel-infoleak in raw_cmd_copyout()
Date: Wed, 29 Jul 2020 16:42:14 +0300 [thread overview]
Message-ID: <20200729134214.GA5493@kadam> (raw)
In-Reply-To: <f2cf6137-987a-ab41-d88a-6828d46c255f@linux.com>
On Wed, Jul 29, 2020 at 04:22:41PM +0300, Denis Efremov wrote:
>
> On 7/29/20 3:58 PM, Dan Carpenter wrote:
> > Argh... This isn't right still. The "ptr" comes from raw_cmd_copyin()
> >
> > ptr = kmalloc(sizeof(struct floppy_raw_cmd), GFP_KERNEL);
> >
>
> copy_from_user overwrites the padding bytes:
> ptr = kmalloc(sizeof(struct floppy_raw_cmd), GFP_KERNEL);
> if (!ptr)
> return -ENOMEM;
> *rcmd = ptr;
> ret = copy_from_user(ptr, param, sizeof(*ptr));
>
> I think memcpy should be safe in this patch.
Oh yeah. You're right. My bad. I just saw the:
ptr->next = NULL;
ptr->buffer_length = 0;
ptr->kernel_data = NULL;
Assignments and I missed the copy_from_user.
regards,
dan carpenter
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next prev parent reply other threads:[~2020-07-29 13:42 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-28 14:19 [Linux-kernel-mentees] [PATCH] block/floppy: Prevent kernel-infoleak in raw_cmd_copyout() Peilin Ye
2020-07-29 9:07 ` Denis Efremov
2020-07-29 9:18 ` Denis Efremov
2020-07-29 9:46 ` Peilin Ye
2020-07-29 11:51 ` [Linux-kernel-mentees] [PATCH v2] " Peilin Ye
2020-07-29 12:58 ` Dan Carpenter
2020-07-29 13:22 ` Denis Efremov
2020-07-29 13:42 ` Dan Carpenter [this message]
2020-07-30 8:11 ` Arnd Bergmann
2020-07-30 18:10 ` Kees Cook
2020-07-30 20:45 ` Arnd Bergmann
2021-07-23 22:22 ` Kees Cook
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