Hi, Yes it should be backported to stables. This bug existed for a while.
On Mon, Sep 23, 2013 at 5:29 AM, Jonghwan Choi <[email protected]> wrote: > From: Anatol Pomozov <[email protected]> > > This patch looks like it should be in the 3.11-stable tree, should we apply > it? > > ------------------ > > From: "Anatol Pomozov <[email protected]>" > > commit f3cff25f05f2ac29b2ee355e611b0657482f6f1d upstream > > 'samples' is 64bit operant, but do_div() second parameter is 32. > do_div silently truncates high 32 bits and calculated result > is invalid. > > In case if low 32bit of 'samples' are zeros then do_div() produces > kernel crash. > > Signed-off-by: Anatol Pomozov <[email protected]> > Acked-by: Tejun Heo <[email protected]> > Signed-off-by: Jens Axboe <[email protected]> > Signed-off-by: Jonghwan Choi <[email protected]> > --- > block/cfq-iosched.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c > index d5bbdcf..c410752 100644 > --- a/block/cfq-iosched.c > +++ b/block/cfq-iosched.c > @@ -1803,7 +1803,7 @@ static u64 cfqg_prfill_avg_queue_size(struct seq_file > *sf, > > if (samples) { > v = blkg_stat_read(&cfqg->stats.avg_queue_size_sum); > - do_div(v, samples); > + v = div64_u64(v, samples); > } > __blkg_prfill_u64(sf, pd, v); > return 0; > -- > 1.8.1.2 > -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
