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authorYonghong Song <yonghong.song@linux.dev>2023-12-21 19:18:01 -0800
committerAlexei Starovoitov <ast@kernel.org>2024-01-03 21:08:26 -0800
commit5c1a37653260ed5d9c8b26fb7fe7b99629612982 (patch)
tree9cd3e4d1531ee6e46147d65ebc3dce1259409b15 /kernel
parent0e2ba9f96f9b82893ba19170ae48d46003f8ef44 (diff)
bpf: Limit up to 512 bytes for bpf_global_percpu_ma allocation
For percpu data structure allocation with bpf_global_percpu_ma, the maximum data size is 4K. But for a system with large number of cpus, bigger data size (e.g., 2K, 4K) might consume a lot of memory. For example, the percpu memory consumption with unit size 2K and 1024 cpus will be 2K * 1K * 1k = 2GB memory. We should discourage such usage. Let us limit the maximum data size to be 512 for bpf_global_percpu_ma allocation. Acked-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20231222031801.1290841-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/verifier.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index e9699a2cfe4f..d5f4ff1eb235 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -195,6 +195,8 @@ struct bpf_verifier_stack_elem {
POISON_POINTER_DELTA))
#define BPF_MAP_PTR(X) ((struct bpf_map *)((X) & ~BPF_MAP_PTR_UNPRIV))
+#define BPF_GLOBAL_PERCPU_MA_MAX_SIZE 512
+
static int acquire_reference_state(struct bpf_verifier_env *env, int insn_idx);
static int release_reference(struct bpf_verifier_env *env, int ref_obj_id);
static void invalidate_non_owning_refs(struct bpf_verifier_env *env);
@@ -12160,6 +12162,12 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
}
if (meta.func_id == special_kfunc_list[KF_bpf_percpu_obj_new_impl]) {
+ if (ret_t->size > BPF_GLOBAL_PERCPU_MA_MAX_SIZE) {
+ verbose(env, "bpf_percpu_obj_new type size (%d) is greater than %d\n",
+ ret_t->size, BPF_GLOBAL_PERCPU_MA_MAX_SIZE);
+ return -EINVAL;
+ }
+
if (!bpf_global_percpu_ma_set) {
mutex_lock(&bpf_percpu_ma_lock);
if (!bpf_global_percpu_ma_set) {