Re: [PATCH v2 2/4] mtd: cfi_cmdset_0002: fix SEGV unlocking multiple chips

[Boris Brezillon <boris.brezillon@bootlin.com>]

On Wed,  6 Jun 2018 12:13:28 +0200
Joakim Tjernlund <joakim.tjernlund@infinera.com> wrote:

> cfi_ppb_unlock() tries to relock all sectors that was locked before

						    ^ were

> unlocking the whole chip.
> This locking used the chip start address + the FULL offset from the
> first flash chip, thereby forming an illegal address. Correct by using

							Fix/Correct that by... ?

> the chip offset(adr).
> 
> Fixes: 1648eaaa1575 ("mtd: cfi_cmdset_0002: Support Persistent Protection Bits (PPB) locking")
> Cc: stable@vger.kernel.org
> Signed-off-by: Joakim Tjernlund <joakim.tjernlund@infinera.com>
> ---
> 
>  v2 - Spilt into several patches
>  
>  drivers/mtd/chips/cfi_cmdset_0002.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
> index 8648b1adccd5..cb85cccc48c1 100644
> --- a/drivers/mtd/chips/cfi_cmdset_0002.c
> +++ b/drivers/mtd/chips/cfi_cmdset_0002.c
> @@ -2536,7 +2536,7 @@ static int cfi_atmel_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
>  
>  struct ppb_lock {
>  	struct flchip *chip;
> -	loff_t offset;
> +	unsigned long adr;
>  	int locked;
>  };
>  
> @@ -2672,7 +2672,7 @@ static int __maybe_unused cfi_ppb_unlock(struct mtd_info *mtd, loff_t ofs,
>  		 */
>  		if ((adr < ofs) || (adr >= (ofs + len))) {
>  			sect[sectors].chip = &cfi->chips[chipnum];
> -			sect[sectors].offset = offset;
> +			sect[sectors].adr = adr;
>  			sect[sectors].locked = do_ppb_xxlock(
>  				map, &cfi->chips[chipnum], adr, 0,
>  				DO_XXLOCK_ONEBLOCK_GETLOCK);
> @@ -2716,7 +2716,7 @@ static int __maybe_unused cfi_ppb_unlock(struct mtd_info *mtd, loff_t ofs,
>  	 */
>  	for (i = 0; i < sectors; i++) {
>  		if (sect[i].locked)
> -			do_ppb_xxlock(map, sect[i].chip, sect[i].offset, 0,
> +			do_ppb_xxlock(map, sect[i].chip, sect[i].adr, 0,
>  				      DO_XXLOCK_ONEBLOCK_LOCK);
>  	}
>