On Fri, Jul 12, 2024 at 12:28:57PM GMT, Youling Tang wrote: > Hi, Kent > > On 12/07/2024 12:07, Kent Overstreet wrote: > > On Fri, Jul 12, 2024 at 11:25:54AM GMT, Youling Tang wrote: > > > From: Youling Tang <tangyouling@xxxxxxxxxx> > > > > > > Note that list_lru_from_memcg_idx() may return NULL, so it is necessary > > > to error handle the return value to avoid triggering NULL pointer > > > dereference BUG. > > > > > > The issue was triggered for discussion [1], > > > Link [1]: https://lore.kernel.org/linux-bcachefs/84de6cb1-57bd-42f7-8029-4203820ef0b4@xxxxxxxxx/T/#m901bb26cdb1d9d4bacebf0d034f0a5a712cc93a6 > > I see no explanation for why this is the correct fix, and I doubt it is. > > What's the real reason for the NULL lru_list_one, and why doesn't this > > come up on other filesystems? > We can break it down into two questions (independent of each other): > 1) Error handling is necessary when l (lru_list_one) is NULL here. No, you're just hiding the actual bug - since I wasn't clear, I'm naking this patch.
