linux-kernel - Re: [PATCH] megaraid: Fix a sleep-in-atomic bug

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] [day] [month] [year] [list]

Date:   Thu, 01 Jun 2017 11:38:51 +0800
From:   Jia-Ju Bai <baijiaju1990@....com>
To:     Sumit Saxena <sumit.saxena@...adcom.com>
CC:     Kashyap Desai <kashyap.desai@...adcom.com>,
        Shivasharan Srikanteshwara 
        <shivasharan.srikanteshwara@...adcom.com>, jejb@...ux.vnet.ibm.com,
        martin.petersen@...cle.com,
        "PDL,MEGARAIDLINUX" <megaraidlinux.pdl@...adcom.com>,
        linux-scsi@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] megaraid: Fix a sleep-in-atomic bug

On 05/31/2017 06:18 PM, Sumit Saxena wrote:
>> -----Original Message-----
>> From: Jia-Ju Bai [mailto:baijiaju1990@....com]
>> Sent: Wednesday, May 31, 2017 8:27 AM
>> To: kashyap.desai@...adcom.com; sumit.saxena@...adcom.com;
>> shivasharan.srikanteshwara@...adcom.com; jejb@...ux.vnet.ibm.com;
>> martin.petersen@...cle.com
>> Cc: megaraidlinux.pdl@...adcom.com; linux-scsi@...r.kernel.org; linux-
>> kernel@...r.kernel.org; Jia-Ju Bai
>> Subject: [PATCH] megaraid: Fix a sleep-in-atomic bug
>>
>> The driver may sleep under a spin lock, and the function call path is:
>> mraid_mm_attach_buf (acquire the lock by spin_lock_irqsave)
>>   pci_pool_alloc(GFP_KERNEL) -->  may sleep
>>
>> To fix it, the "GFP_KERNEL" is replaced with "GFP_ATOMIC".
>>
>> Signed-off-by: Jia-Ju Bai<baijiaju1990@....com>
>> ---
>> drivers/scsi/megaraid/megaraid_mm.c |    2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/scsi/megaraid/megaraid_mm.c
>> b/drivers/scsi/megaraid/megaraid_mm.c
>> index 4cf9ed9..c43afb8 100644
>> --- a/drivers/scsi/megaraid/megaraid_mm.c
>> +++ b/drivers/scsi/megaraid/megaraid_mm.c
>> @@ -574,7 +574,7 @@
>>
>> 	kioc->pool_index	= right_pool;
>> 	kioc->free_buf		= 1;
>> -	kioc->buf_vaddr 	= pci_pool_alloc(pool->handle, GFP_KERNEL,
>> +	kioc->buf_vaddr 	= pci_pool_alloc(pool->handle, GFP_ATOMIC,
>> 							&kioc->buf_paddr);
>> 	spin_unlock_irqrestore(&pool->lock, flags);
> This is very old driver and reached EOL. Did you face any issue because of
> this bug or discover this through code review?
> Anyways patch looks good to me.
>
> Acked-by: Sumit Saxena<sumit.saxena@...adcom.com>
>
>> --
>> 1.7.9.5
>>
Hi,

This bug is found by a static analysis tool and my code review.

Jia-Ju Bai