Commit 3ac1a467e376 for kernel

commit 3ac1a467e37683f602221e243fa3c59b0de81165
Author: Junyoung Jang <graypanda.inzag@gmail.com>
Date:   Mon Apr 27 02:25:05 2026 +0900

    bpf: Fix off-by-one boundary validation in arena direct-value access

    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.

    Fixes: 317460317a02 ("bpf: Introduce bpf_arena.")
    Signed-off-by: Junyoung Jang <graypanda.inzag@gmail.com>
    Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
    Link: https://lore.kernel.org/r/20260426172505.1947915-1-graypanda.inzag@gmail.com
    Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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;