On 01/06/12 16:20, Torne (Richard Coles) wrote: > From: "Torne (Richard Coles)" <torne@xxxxxxxxxx> > > MMC CSD info can specify very large, ridiculous timeouts, big enough to > overflow timeout_ns. This can result in the card timing out on every > operation because the wrapped timeout value is far too small. > > Fix the overflow by capping the result at UINT_MAX. Cards specifying > longer timeouts are almost certainly insane, and host controllers > generally cannot support timeouts that long in any case. > > Signed-off-by: Torne (Richard Coles) <torne@xxxxxxxxxx> > --- > drivers/mmc/core/core.c | 11 ++++++++++- > 1 files changed, 10 insertions(+), 1 deletions(-) > > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > index 0b6141d..74ec3d4 100644 > --- a/drivers/mmc/core/core.c > +++ b/drivers/mmc/core/core.c > @@ -512,7 +512,16 @@ void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card) > if (data->flags & MMC_DATA_WRITE) > mult <<= card->csd.r2w_factor; > > - data->timeout_ns = card->csd.tacc_ns * mult; > + /* > + * The timeout in nanoseconds may overflow with some cards. Cap it at > + * UINT_MAX to avoid the overflow; host controllers cannot generally > + * generate timeouts that long anyway. > + */ > + if (card->csd.tacc_ns <= UINT_MAX / mult) > + data->timeout_ns = card->csd.tacc_ns * mult; > + else > + data->timeout_ns = UINT_MAX; > + > data->timeout_clks = card->csd.tacc_clks * mult; > > /* Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
