Colin,
Am Mittwoch, 8. November 2017, 16:57:57 CET schrieb Colin Ian King:
> On 08/11/17 15:46, Colin King wrote:
> > From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> >
> > Multiplying block_num and mtd->erasesize may potentially overflow
> > as they are both unsigned ints and so the multiplication is evaluated
> > in unsigned int arithmetic . Cast block_adr to off_t to ensure
> > multiplication is off_t sized to avoid any potential overflow.
> >
> > Detected by CoverityScan, CID#1461264 ("Unintentional integer overflow")
> >
> > Fixes: fff1e32a50c0 ("mtd: sharpslpart: Add sharpslpart partition parser")
> > Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> > ---
> >
> > drivers/mtd/parsers/sharpslpart.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/mtd/parsers/sharpslpart.c
> > b/drivers/mtd/parsers/sharpslpart.c index 5fe0079ea5ed..b1d97aa3bac4
> > 100644
> > --- a/drivers/mtd/parsers/sharpslpart.c
> > +++ b/drivers/mtd/parsers/sharpslpart.c
> > @@ -244,7 +244,7 @@ static int sharpsl_nand_read_laddr(struct mtd_info
> > *mtd,>
> > return -EINVAL;
> >
> > block_num = ftl->log2phy[log_num];
> >
> > - block_adr = block_num * mtd->erasesize;
> > + block_adr = (loff_t)block_num * mtd->erasesize;
> >
> > block_ofs = mtd_mod_by_eb((u32)from, mtd);
> >
> > err = mtd_read(mtd, block_adr + block_ofs, len, &retlen, buf);
>
> Sorry, ignore this, there is another place that does this that needs
> some attention. I'll sent V2 shortly.
No need to hurry. :)
I agree that such overflows should be addressed, although they are purely
theoretical. MTD is being used on small devices only.
Thanks,
//richard
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