Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH v1] timerqueue: use rb_entry_safe() in timerqueue_getnext() | Date | Mon, 14 Nov 2022 20:16:24 +0100 |
| |
On Mon, Nov 14 2022 at 15:54, Barnabás Pőcze wrote: > 2022. november 14., hétfő 1:17 keltezéssel, Thomas Gleixner írta: >> On Thu, Oct 27 2022 at 21:37, Barnabás Pőcze wrote: > > When `timerqueue_getnext()` is called on an empty timer queue, it will > use `rb_entry()` on a NULL pointer, which is invalid. Fix that by using > `rb_entry_safe()` which handles NULL pointers. > > This has not caused any issues so far because the offset of the `rb_node` > member in `timerqueue_node` is 0, so `rb_entry()` is essentially a > no-op.
Yes. Very precise and informative.
>> Back then when that code got introduced rb_entry_safe() did not exist at >> all so it's even more obvious that this is simply a missing NULL pointer >> check, right? > > As far as I can tell it did exist and it was actually used > when the offending change was committed (511885d7061e).
Hmm. I must have messed up when searching in the history.
Thanks,
tglx
| |