From: Jiri Olsa Date: Tue, 17 Jan 2023 22:37:04 +0000 (+0100) Subject: bpf: Do not allow to load sleepable BPF_TRACE_RAW_TP program X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=700e6f853eb3977cd1cf172b717baa9daa328ea4;p=linux.git bpf: Do not allow to load sleepable BPF_TRACE_RAW_TP program Currently we allow to load any tracing program as sleepable, but BPF_TRACE_RAW_TP can't sleep. Making the check explicit for tracing programs attach types, so sleepable BPF_TRACE_RAW_TP will fail to load. Updating the verifier error to mention iter programs as well. Acked-by: Song Liu Acked-by: Yonghong Song Signed-off-by: Jiri Olsa Link: https://lore.kernel.org/r/20230117223705.440975-1-jolsa@kernel.org Signed-off-by: Alexei Starovoitov --- diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index fa4c911603e90..ca7db2ce70b94 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -16743,6 +16743,23 @@ BTF_ID(func, rcu_read_unlock_strict) #endif BTF_SET_END(btf_id_deny) +static bool can_be_sleepable(struct bpf_prog *prog) +{ + if (prog->type == BPF_PROG_TYPE_TRACING) { + switch (prog->expected_attach_type) { + case BPF_TRACE_FENTRY: + case BPF_TRACE_FEXIT: + case BPF_MODIFY_RETURN: + case BPF_TRACE_ITER: + return true; + default: + return false; + } + } + return prog->type == BPF_PROG_TYPE_LSM || + prog->type == BPF_PROG_TYPE_KPROBE; /* only for uprobes */ +} + static int check_attach_btf_id(struct bpf_verifier_env *env) { struct bpf_prog *prog = env->prog; @@ -16761,9 +16778,8 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) return -EINVAL; } - if (prog->aux->sleepable && prog->type != BPF_PROG_TYPE_TRACING && - prog->type != BPF_PROG_TYPE_LSM && prog->type != BPF_PROG_TYPE_KPROBE) { - verbose(env, "Only fentry/fexit/fmod_ret, lsm, and kprobe/uprobe programs can be sleepable\n"); + if (prog->aux->sleepable && !can_be_sleepable(prog)) { + verbose(env, "Only fentry/fexit/fmod_ret, lsm, iter and uprobe programs can be sleepable\n"); return -EINVAL; }