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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Denis Efremov <efremov@linux.com>
Cc: Peilin Ye <yepeilin.cs@gmail.com>, 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
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


WARNING: multiple messages have this Message-ID (diff)
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

_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees

  reply	other threads:[~2020-07-29 13:42 UTC|newest]

Thread overview: 24+ 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
2020-07-28 14:19 ` Peilin Ye
2020-07-29  9:07 ` Denis Efremov
2020-07-29  9:07   ` Denis Efremov
2020-07-29  9:18 ` Denis Efremov
2020-07-29  9:18   ` Denis Efremov
2020-07-29  9:46   ` Peilin Ye
2020-07-29  9:46     ` Peilin Ye
2020-07-29 11:51 ` [Linux-kernel-mentees] [PATCH v2] " Peilin Ye
2020-07-29 11:51   ` Peilin Ye
2020-07-29 12:58   ` Dan Carpenter
2020-07-29 12:58     ` Dan Carpenter
2020-07-29 13:22     ` Denis Efremov
2020-07-29 13:22       ` Denis Efremov
2020-07-29 13:42       ` Dan Carpenter [this message]
2020-07-29 13:42         ` Dan Carpenter
2020-07-30  8:11       ` Arnd Bergmann
2020-07-30  8:11         ` Arnd Bergmann
2020-07-30 18:10         ` Kees Cook
2020-07-30 18:10           ` Kees Cook
2020-07-30 20:45           ` Arnd Bergmann
2020-07-30 20:45             ` Arnd Bergmann
2021-07-23 22:22             ` Kees Cook
2021-07-23 22:22               ` Kees Cook

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