Re: CVS commit: src/sys/dev

[Michael van Elst <mlelstv%serpens.de@localhost>]

On Sat, Apr 12, 2025 at 08:14:28PM +0900, Rin Okuyama wrote:
> Hi Michael, thanks for kind review!

Hi rin,


> PS
> For ld_sdmmc.c, IIUC, check for ld_sdmmc_dump() yields
> 
> ```
> if (blkno + blkcnt - 1 > sc->sc_sf->csd.capacity)
> 	return EIO;


capacity is the block count, not the last block number. So there
you need to check

if (blkno + blkcnt > sc->sc_sf->csd.capacity)
	return EIO;

or

if (blkno + blkcnt - 1 >= sc->sc_sf->csd.capacity)
	return EIO;



> If so, shouldn't we take into account b_bcount for ld_sdmmc_dobio()?
> https://nxr.netbsd.org/xref/src/sys/dev/sdmmc/ld_sdmmc.c#458

Yes. It needs to take into account b_bcount.

However, all I/O is already validated before it reaches the driver,
the condition in ld_sdmmc.c will never be met.

Almost all disk drivers use helper routines in sys/dev/dksubr.c.

dk_translate does the validation for regular I/O by calling
bounds_check_with_mediasize() or bounds_check_with_label().

dk_dump does the validation for a dump operation directly
against the disk_geom data.


Greetings,
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."