diff options
| author | Hou Tao | 2022-03-09 20:33:20 +0800 |
|---|---|---|
| committer | Alexei Starovoitov | 2022-03-16 15:13:36 -0700 |
| commit | d2a3b7c5becc3992f8e7d2b9bf5eacceeedb9a48 (patch) | |
| tree | c70bd9195500322ed9bbf0e4b783e9038dc3ffee /kernel/bpf | |
| parent | 73e14451f39e54f83ea3badb6d6b8a423f901845 (diff) | |
bpf: Fix net.core.bpf_jit_harden race
It is the bpf_jit_harden counterpart to commit 60b58afc96c9 ("bpf: fix
net.core.bpf_jit_enable race"). bpf_jit_harden will be tested twice
for each subprog if there are subprogs in bpf program and constant
blinding may increase the length of program, so when running
"./test_progs -t subprogs" and toggling bpf_jit_harden between 0 and 2,
jit_subprogs may fail because constant blinding increases the length
of subprog instructions during extra passs.
So cache the value of bpf_jit_blinding_enabled() during program
allocation, and use the cached value during constant blinding, subprog
JITing and args tracking of tail call.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220309123321.2400262-4-houtao1@huawei.com
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/core.c | 3 | ||||
| -rw-r--r-- | kernel/bpf/verifier.c | 5 |
2 files changed, 5 insertions, 3 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index ab630f773ec1..1324f9523e7c 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -105,6 +105,7 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag fp->aux = aux; fp->aux->prog = fp; fp->jit_requested = ebpf_jit_enabled(); + fp->blinding_requested = bpf_jit_blinding_enabled(fp); INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode); mutex_init(&fp->aux->used_maps_mutex); @@ -1382,7 +1383,7 @@ struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog) struct bpf_insn *insn; int i, rewritten; - if (!bpf_jit_blinding_enabled(prog) || prog->blinded) + if (!prog->blinding_requested || prog->blinded) return prog; clone = bpf_prog_clone_create(prog, GFP_USER); diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 0db6cd8dcb35..cf92f9c01556 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -13023,6 +13023,7 @@ static int jit_subprogs(struct bpf_verifier_env *env) func[i]->aux->name[0] = 'F'; func[i]->aux->stack_depth = env->subprog_info[i].stack_depth; func[i]->jit_requested = 1; + func[i]->blinding_requested = prog->blinding_requested; func[i]->aux->kfunc_tab = prog->aux->kfunc_tab; func[i]->aux->kfunc_btf_tab = prog->aux->kfunc_btf_tab; func[i]->aux->linfo = prog->aux->linfo; @@ -13146,6 +13147,7 @@ out_free: out_undo_insn: /* cleanup main prog to be interpreted */ prog->jit_requested = 0; + prog->blinding_requested = 0; for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) { if (!bpf_pseudo_call(insn)) continue; @@ -13239,7 +13241,6 @@ static int do_misc_fixups(struct bpf_verifier_env *env) { struct bpf_prog *prog = env->prog; enum bpf_attach_type eatype = prog->expected_attach_type; - bool expect_blinding = bpf_jit_blinding_enabled(prog); enum bpf_prog_type prog_type = resolve_prog_type(prog); struct bpf_insn *insn = prog->insnsi; const struct bpf_func_proto *fn; @@ -13403,7 +13404,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env) insn->code = BPF_JMP | BPF_TAIL_CALL; aux = &env->insn_aux_data[i + delta]; - if (env->bpf_capable && !expect_blinding && + if (env->bpf_capable && !prog->blinding_requested && prog->jit_requested && !bpf_map_key_poisoned(aux) && !bpf_map_ptr_poisoned(aux) && |