Messages in this thread | | | Date | Wed, 27 Jan 2021 12:09:37 +0700 | From | Bui Quang Minh <> | Subject | Re: [PATCH] bpf: Fix integer overflow in argument calculation for bpf_map_area_alloc |
| |
On Wed, Jan 27, 2021 at 11:23:41AM +0700, Bui Quang Minh wrote: > > * Seems like there are quite a few similar calls scattered around > > (cpumap, etc.). Did you audit these as well? > > I spotted another bug after re-auditting. In hashtab, there ares 2 places using > the same calls > > static struct bpf_map *htab_map_alloc(union bpf_attr *attr) > { > /* ... snip ... */ > if (htab->n_buckets == 0 || > htab->n_buckets > U32_MAX / sizeof(struct bucket)) > goto free_htab; > > htab->buckets = bpf_map_area_alloc(htab->n_buckets * > sizeof(struct bucket), > htab->map.numa_node); > } > > This is safe because of the above check. > > static int prealloc_init(struct bpf_htab *htab) > { > u32 num_entries = htab->map.max_entries; > htab->elems = bpf_map_area_alloc(htab->elem_size * num_entries, > htab->map.numa_node); > } > > This is not safe since there is no limit check in elem_size.
So sorry but I rechecked and saw this bug in hashtab has been fixed with commit e1868b9e36d0ca
Thank you, Quang Minh.
| |