On Thu, Jun 23, 2022 at 9:10 PM Eric Biggers <ebiggers@xxxxxxxxxx> wrote:
>
> On Thu, Jun 23, 2022 at 09:00:14PM +0200, Jason A. Donenfeld wrote:
> > The rng's random_init() function contributes the real time to the rng at
> > boot time, so that events can at least start in relation to something
> > particular in the real world. But this clock might not yet be set that
> > point in boot, so nothing is contributed. In addition, the relation
> > between minor clock changes from, say, NTP, and the cycle counter is
> > potentially useful entropic data.
> >
> > This commit addresses this by mixing in a time stamp on calls to
> > settimeofday and adjtimex. No entropy is credited in doing so, so it
> > doesn't make initialization faster, but it is still useful input to
> > have.
> >
> > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
> > ---
> > kernel/time/timekeeping.c | 7 ++++++-
> > 1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
> > index 8e4b3c32fcf9..49ee8ef16544 100644
> > --- a/kernel/time/timekeeping.c
> > +++ b/kernel/time/timekeeping.c
> > @@ -23,6 +23,7 @@
> > #include <linux/pvclock_gtod.h>
> > #include <linux/compiler.h>
> > #include <linux/audit.h>
> > +#include <linux/random.h>
> >
> > #include "tick-internal.h"
> > #include "ntp_internal.h"
> > @@ -1343,8 +1344,10 @@ int do_settimeofday64(const struct timespec64 *ts)
> > /* Signal hrtimers about time change */
> > clock_was_set(CLOCK_SET_WALL);
> >
> > - if (!ret)
> > + if (!ret) {
> > audit_tk_injoffset(ts_delta);
> > + add_device_randomness(&ts, sizeof(ts));
> > + }
>
> It should be:
>
> add_device_randomness(ts, sizeof(*ts));
This simple patch... I swear I know C, I promise...
Thanks again, and sorry.
Jason
