Re: BUG: NULL pointer dereference at 00000000 -- IP: [] :b43:b43_dma_mapping_error+0x16/0x155

Larry Finger
2008-06-11T12:23:25Z

Michael Buesch wrote:
> On Wednesday 11 June 2008 02:58:44 FUJITA Tomonori wrote:
>> On Tue, 10 Jun 2008 16:50:26 +0200
>> Michael Buesch <mb@bu3sch.de> wrote:
>>
>>> On Tuesday 10 June 2008 16:42:41 Vegard Nossum wrote:
>>>> This change comes from
>>>>
>>>> commit 353c409463ecba63c3a41a992d3f5fba935eada9
>>>> Author: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
>>>> Date: Fri May 23 19:02:30 2008 +0000
>>>
>>> Ok, FUJITA Tomonori, please make sure a patch like the following goes
>>> into the same trees that you submitted commit 353c409 to.
>>> Also make sure to check b43legacy. I _guess_ you might have added
>>> the same bug there.
>> Ah, sorry about the bug.
>>
>> From a quick look, mainline needs the same fix too?
>>
>> b43_dma_mapping_error calls unmap_descbuffer() on the failure, which
>> assumes that ring->dev is set up properly.
>
> Yeah ok. That's an unlikely error path.
> The new bug is in the main path which will always trigger.
>
> Next time please send _any_ patch for review to me and to the wireless list.
> Please tell me which trees this bug has been merged to. Is it already in
> Linus' tree?

The equivalent line in Linus's tree is "if
(unlikely(dma_mapping_error(addr)))", thus the error has not reached
mainline (yet?).

Larry