[PATCH v2 1/2] Fix corner case in bad block table handling.

[Frieder Schrempf]

Hi Greg, Sasha,

just a gentle ping for the backport request below.

Thanks!

Am 11.01.22 um 16:33 schrieb Frieder Schrempf:
> Hi stable maintainers,
> 
> On 06.04.21 03:47, Yoshio Furuyama wrote:
>> From: "Doyle, Patrick" <pdoyle at irobot.com>
>>
>> In the unlikely event that both blocks 10 and 11 are marked as bad (on a
>> 32 bit machine), then the process of marking block 10 as bad stomps on
>> cached entry for block 11.  There are (of course) other examples.
>>
>> Signed-off-by: Patrick Doyle <pdoyle at irobot.com>
>> Reviewed-by: Richard Weinberger <richard at nod.at>
> 
> We have systems on which this patch fixes real failures. Could you
> please add the upstream patch fd0d8d85f723 ("mtd: nand: bbt: Fix corner
> case in bad block table handling") to the stable queues for 4.19, 5.4, 5.10?
> 
> Thanks!
> 
> Cc: stable at vger.kernel.org
> Fixes: 9c3736a3de21 ("mtd: nand: Add core infrastructure to deal with
> NAND devices")
> 
>> ---
>>  drivers/mtd/nand/bbt.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/mtd/nand/bbt.c b/drivers/mtd/nand/bbt.c
>> index 044adf913854..64af6898131d 100644
>> --- a/drivers/mtd/nand/bbt.c
>> +++ b/drivers/mtd/nand/bbt.c
>> @@ -123,7 +123,7 @@ int nanddev_bbt_set_block_status(struct nand_device *nand, unsigned int entry,
>>  		unsigned int rbits = bits_per_block + offs - BITS_PER_LONG;
>>  
>>  		pos[1] &= ~GENMASK(rbits - 1, 0);
>> -		pos[1] |= val >> rbits;
>> +		pos[1] |= val >> (bits_per_block - rbits);
>>  	}
>>  
>>  	return 0;