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| author | Amery Hung <ameryhung@gmail.com> | 2025-09-22 16:33:52 -0700 |
|---|---|---|
| committer | Martin KaFai Lau <martin.lau@kernel.org> | 2025-09-23 13:35:12 -0700 |
| commit | 0e7a733ab3d7be8d745e8ee38d637ea7a9b24343 (patch) | |
| tree | 77c033d216d4f20bda2be2f01f76dc51be5fb7b8 /kernel | |
| parent | bpf: Support pulling non-linear xdp data (diff) | |
| download | linux-0e7a733ab3d7be8d745e8ee38d637ea7a9b24343.tar.gz linux-0e7a733ab3d7be8d745e8ee38d637ea7a9b24343.zip | |
bpf: Clear packet pointers after changing packet data in kfuncs
bpf_xdp_pull_data() may change packet data and therefore packet pointers
need to be invalidated. Add bpf_xdp_pull_data() to the special kfunc
list instead of introducing a new KF_ flag until there are more kfuncs
changing packet data.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250922233356.3356453-5-ameryhung@gmail.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 5964bed40ffb..a1dd3c31a09e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -12235,6 +12235,7 @@ enum special_kfunc_type { KF_bpf_dynptr_from_skb, KF_bpf_dynptr_from_xdp, KF_bpf_dynptr_from_skb_meta, + KF_bpf_xdp_pull_data, KF_bpf_dynptr_slice, KF_bpf_dynptr_slice_rdwr, KF_bpf_dynptr_clone, @@ -12285,10 +12286,12 @@ BTF_ID(func, bpf_rbtree_right) BTF_ID(func, bpf_dynptr_from_skb) BTF_ID(func, bpf_dynptr_from_xdp) BTF_ID(func, bpf_dynptr_from_skb_meta) +BTF_ID(func, bpf_xdp_pull_data) #else BTF_ID_UNUSED BTF_ID_UNUSED BTF_ID_UNUSED +BTF_ID_UNUSED #endif BTF_ID(func, bpf_dynptr_slice) BTF_ID(func, bpf_dynptr_slice_rdwr) @@ -12358,6 +12361,11 @@ static bool is_kfunc_bpf_preempt_enable(struct bpf_kfunc_call_arg_meta *meta) return meta->func_id == special_kfunc_list[KF_bpf_preempt_enable]; } +static bool is_kfunc_pkt_changing(struct bpf_kfunc_call_arg_meta *meta) +{ + return meta->func_id == special_kfunc_list[KF_bpf_xdp_pull_data]; +} + static enum kfunc_ptr_arg_type get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, struct bpf_kfunc_call_arg_meta *meta, @@ -14077,6 +14085,9 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, } } + if (is_kfunc_pkt_changing(&meta)) + clear_all_pkt_pointers(env); + nargs = btf_type_vlen(meta.func_proto); args = (const struct btf_param *)(meta.func_proto + 1); for (i = 0; i < nargs; i++) { @@ -17794,6 +17805,8 @@ static int visit_insn(int t, struct bpf_verifier_env *env) */ if (ret == 0 && is_kfunc_sleepable(&meta)) mark_subprog_might_sleep(env, t); + if (ret == 0 && is_kfunc_pkt_changing(&meta)) + mark_subprog_changes_pkt_data(env, t); } return visit_func_call_insn(t, insns, env, insn->src_reg == BPF_PSEUDO_CALL); |