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| author | Junyoung Jang <graypanda.inzag@gmail.com> | 2026-04-26 20:25:05 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-05-10 02:18:39 +0300 |
| commit | 3ac1a467e37683f602221e243fa3c59b0de81165 (patch) | |
| tree | 6d94789f54da9f5664370898c5c5e4d56d49b4a0 | |
| parent | bf6d507f7e3c65751d52fd8caf1ea4e003922624 (diff) | |
| download | linux-3ac1a467e37683f602221e243fa3c59b0de81165.tar.xz | |
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>
| -rw-r--r-- | kernel/bpf/arena.c | 2 |
1 files changed, 1 insertions, 1 deletions
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; |