diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 1eeb31c5b..241f11d4d 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c
[ ... ]
@@ -398,18 +405,18 @@ int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, struct bpf_array *array = container_of(map, struct bpf_array, map); u32 index = *(u32 *)key; void __percpu *pptr;
- int cpu, off = 0;
- void *ptr, *val; u32 size;
- int cpu;
- if (unlikely(map_flags > BPF_EXIST))
/* unknown flags */
if (unlikely(map_flags & BPF_F_LOCK)) return -EINVAL;
if (unlikely(index >= array->map.max_entries)) /* all elements were pre-allocated, cannot insert a new one */ return -E2BIG;
- if (unlikely(map_flags == BPF_NOEXIST))
- if (unlikely(map_flags & BPF_NOEXIST)) /* all elements already exist */ return -EEXIST;
This isn't a bug, but the change from equality check to bit test might allow confusing flag combinations. The old code rejected map_flags > 2, which prevented BPF_NOEXIST | BPF_EXIST (flags=3) entirely. With the new bit test, userspace can pass both flags and BPF_NOEXIST takes precedence.
Should bpf_map_check_op_flags() validate mutual exclusivity of BPF_NOEXIST and BPF_EXIST, similar to how it validates BPF_F_CPU and BPF_F_ALL_CPUS at include/linux/bpf.h:3858?
--- AI reviewed your patch. Please fix the bug or email reply why it's not a bug. See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
CI run summary: https://github.com/kernel-patches/bpf/actions/runs/19674301388