Re: [RFC PATCH 3/5] mm, slub: remove runtime allocation order changes

2020-06-05 Thread Roman Gushchin
On Tue, Jun 02, 2020 at 04:15:17PM +0200, Vlastimil Babka wrote: > SLUB allows runtime changing of page allocation order by writing into the > /sys/kernel/slab//order file. Jann has reported [1] that this interface > allows the order to be set too small, leading to crashes. > > While it's

Re: [RFC PATCH 3/5] mm, slub: remove runtime allocation order changes

2020-06-05 Thread Kees Cook
On Tue, Jun 02, 2020 at 04:15:17PM +0200, Vlastimil Babka wrote: > SLUB allows runtime changing of page allocation order by writing into the > /sys/kernel/slab//order file. Jann has reported [1] that this interface > allows the order to be set too small, leading to crashes. > > While it's

[RFC PATCH 3/5] mm, slub: remove runtime allocation order changes

2020-06-02 Thread Vlastimil Babka
SLUB allows runtime changing of page allocation order by writing into the /sys/kernel/slab//order file. Jann has reported [1] that this interface allows the order to be set too small, leading to crashes. While it's possible to fix the immediate issue, closer inspection reveals potential races.