On Oct 22, 2024, at 10:26, Hongbo Li <[email protected]> wrote: > > > > On 2024/10/21 23:43, Jeongjun Park wrote: >> The size of a.data_type is set abnormally large, causing shift-out-of-bounds. >> To fix this, we need to add validation on a.data_type in >> alloc_lru_idx_fragmentation(). >> Reported-by: [email protected] >> Fixes: 260af1562ec1 ("bcachefs: Kill alloc_v4.fragmentation_lru") >> Signed-off-by: Jeongjun Park <[email protected]> >> --- >> fs/bcachefs/alloc_background.h | 3 +++ >> 1 file changed, 3 insertions(+) >> diff --git a/fs/bcachefs/alloc_background.h b/fs/bcachefs/alloc_background.h >> index f8e87c6721b1..163a67b97a40 100644 >> --- a/fs/bcachefs/alloc_background.h >> +++ b/fs/bcachefs/alloc_background.h >> @@ -168,6 +168,9 @@ static inline bool data_type_movable(enum bch_data_type >> type) >> static inline u64 alloc_lru_idx_fragmentation(struct bch_alloc_v4 a, >> struct bch_dev *ca) >> { >> + if (a.data_type >= BCH_DATA_NR) >> + return 0; >> + > > oh, I found I have done the same thing in [1]("Re: [syzbot] [bcachefs?] > UBSAN: shift-out-of-bounds in bch2_alloc_to_text"). But
Your patch there is still triggering the issue. > in my humble opinion, the validation changes also should be added. And in > addition, move the condition about a.data_type into There is already the validation: bkey_fsck_err_on(alloc_data_type(a, a.data_type) != a.data_type And the unknown data type is already printed in bch2_prt_data_type, additional validation doesn’t help much. > data_type_movable will be better. Just my personal opinion.:) In my personal opinion, I don’t think so :) > > [1] https://www.spinics.net/lists/kernel/msg5412619.html > > Thanks, > Hongbo > >> if (!data_type_movable(a.data_type) || >> !bch2_bucket_sectors_fragmented(ca, a)) >> return 0; >> --
