linux-kernel - Re: [PATCH] fix vulnerability of the release method of file operations in Block layer SCSI generic driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 11 Nov 2010 21:43:36 +0800
From:	Hillf Danton <dhillf@...il.com>
To:	Matthew Wilcox <matthew@....cx>
Cc:	linux-kernel@...r.kernel.org, linux-scsi@...r.kernel.org,
	"Zou, Yi" <yi.zou@...el.com>, Joe Eykholt <jeykholt@...co.com>
Subject: Re: [PATCH] fix vulnerability of the release method of file
 operations in Block layer SCSI generic driver

On Wed, Nov 10, 2010 at 11:18 PM, Matthew Wilcox <matthew@....cx> wrote:
> On Wed, Nov 10, 2010 at 10:08:37PM +0800, Hillf Danton wrote:
>> The computation context setup by previous opening the bsg file could
>> not survive following open/release operations upon the same file
>> object.
>
> Umm .. release is called on final close of a file, not on every close
> of a file.
>
right, thanks//Hillf

>> The vulnerability is fixed by deferring the cleanup operation until necessary.
>>
>> Signed-off-by: Hillf Danton <dhillf@...il.com>
>> ---
>>
>> --- a/block/bsg.c     2010-09-13 07:07:38.000000000 +0800
>> +++ b/block/bsg.c     2010-11-10 21:43:58.000000000 +0800
>> @@ -858,7 +858,8 @@ static int bsg_release(struct inode *ino
>>  {
>>       struct bsg_device *bd = file->private_data;
>>
>> -     file->private_data = NULL;
>> +     if (1 == atomic_read(&bd->ref_count))
>> +             file->private_data = NULL;
>>       return bsg_put_device(bd);
>>  }
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
>> the body of a message to majordomo@...r.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
> --
> Matthew Wilcox                          Intel Open Source Technology Centre
> "Bill, look, we understand that you're interested in selling us this
> operating system, but compare it to ours.  We can't possibly take such
> a retrograde step."
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/