BPF_MAP_TYPE_ARENA accepts BPF_PSEUDO_MAP_VALUE offsets at exactly
the end of the arena mapping (off == arena_size). The boundary check
in arena_map_direct_value_addr() uses `>` instead of `>=`, which
incorrectly allows a one-past-end pointer to be accepted.
Change the condition to `>=` to correctly reject offsets that fall
outside the valid arena user_vm range.
Signed-off-by: Junyoung Jang <graypanda.inzag@gmail.com>
---
kernel/bpf/arena.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c
index 802656c6fd3c..49a8f7b1beef 100644
--- a/kernel/bpf/arena.c
+++ b/kernel/bpf/arena.c
@@ -511,7 +511,7 @@ static int arena_map_direct_value_addr(const struct bpf_map *map, u64 *imm, u32
{
struct bpf_arena *arena = container_of(map, struct bpf_arena, map);
- if ((u64)off > arena->user_vm_end - arena->user_vm_start)
+ if ((u64)off >= arena->user_vm_end - arena->user_vm_start)
return -ERANGE;
*imm = (unsigned long)arena->user_vm_start;
return 0;
--
2.43.0