From 3505cb9fa26cfec9512744466e754a8cbc2365b0 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 9 Aug 2023 10:34:14 +0200 Subject: [PATCH] bpf: Add attach_type checks under bpf_prog_attach_check_attach_type Add extra attach_type checks from link_create under bpf_prog_attach_check_attach_type. Suggested-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Acked-by: Yafang Shao Signed-off-by: Jiri Olsa Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20230809083440.3209381-3-jolsa@kernel.org Signed-off-by: Alexei Starovoitov --- kernel/bpf/syscall.c | 120 ++++++++++++++++++++++----------------------------- 1 file changed, 52 insertions(+), 68 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index cb65854..b14036c 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3655,34 +3655,6 @@ static int bpf_raw_tracepoint_open(const union bpf_attr *attr) return fd; } -static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, - enum bpf_attach_type attach_type) -{ - switch (prog->type) { - case BPF_PROG_TYPE_CGROUP_SOCK: - case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: - case BPF_PROG_TYPE_CGROUP_SOCKOPT: - case BPF_PROG_TYPE_SK_LOOKUP: - return attach_type == prog->expected_attach_type ? 0 : -EINVAL; - case BPF_PROG_TYPE_CGROUP_SKB: - if (!capable(CAP_NET_ADMIN)) - /* cg-skb progs can be loaded by unpriv user. - * check permissions at attach time. - */ - return -EPERM; - return prog->enforce_expected_attach_type && - prog->expected_attach_type != attach_type ? - -EINVAL : 0; - case BPF_PROG_TYPE_KPROBE: - if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && - attach_type != BPF_TRACE_KPROBE_MULTI) - return -EINVAL; - return 0; - default: - return 0; - } -} - static enum bpf_prog_type attach_type_to_prog_type(enum bpf_attach_type attach_type) { @@ -3749,6 +3721,58 @@ attach_type_to_prog_type(enum bpf_attach_type attach_type) } } +static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, + enum bpf_attach_type attach_type) +{ + enum bpf_prog_type ptype; + + switch (prog->type) { + case BPF_PROG_TYPE_CGROUP_SOCK: + case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: + case BPF_PROG_TYPE_CGROUP_SOCKOPT: + case BPF_PROG_TYPE_SK_LOOKUP: + return attach_type == prog->expected_attach_type ? 0 : -EINVAL; + case BPF_PROG_TYPE_CGROUP_SKB: + if (!capable(CAP_NET_ADMIN)) + /* cg-skb progs can be loaded by unpriv user. + * check permissions at attach time. + */ + return -EPERM; + return prog->enforce_expected_attach_type && + prog->expected_attach_type != attach_type ? + -EINVAL : 0; + case BPF_PROG_TYPE_EXT: + return 0; + case BPF_PROG_TYPE_NETFILTER: + if (attach_type != BPF_NETFILTER) + return -EINVAL; + return 0; + case BPF_PROG_TYPE_PERF_EVENT: + case BPF_PROG_TYPE_TRACEPOINT: + if (attach_type != BPF_PERF_EVENT) + return -EINVAL; + return 0; + case BPF_PROG_TYPE_KPROBE: + if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && + attach_type != BPF_TRACE_KPROBE_MULTI) + return -EINVAL; + if (attach_type != BPF_PERF_EVENT && + attach_type != BPF_TRACE_KPROBE_MULTI) + return -EINVAL; + return 0; + case BPF_PROG_TYPE_SCHED_CLS: + if (attach_type != BPF_TCX_INGRESS && + attach_type != BPF_TCX_EGRESS) + return -EINVAL; + return 0; + default: + ptype = attach_type_to_prog_type(attach_type); + if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) + return -EINVAL; + return 0; + } +} + #define BPF_PROG_ATTACH_LAST_FIELD expected_revision #define BPF_F_ATTACH_MASK_BASE \ @@ -4855,7 +4879,6 @@ err_put: #define BPF_LINK_CREATE_LAST_FIELD link_create.kprobe_multi.cookies static int link_create(union bpf_attr *attr, bpfptr_t uattr) { - enum bpf_prog_type ptype; struct bpf_prog *prog; int ret; @@ -4875,45 +4898,6 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr) goto out; switch (prog->type) { - case BPF_PROG_TYPE_EXT: - break; - case BPF_PROG_TYPE_NETFILTER: - if (attr->link_create.attach_type != BPF_NETFILTER) { - ret = -EINVAL; - goto out; - } - break; - case BPF_PROG_TYPE_PERF_EVENT: - case BPF_PROG_TYPE_TRACEPOINT: - if (attr->link_create.attach_type != BPF_PERF_EVENT) { - ret = -EINVAL; - goto out; - } - break; - case BPF_PROG_TYPE_KPROBE: - if (attr->link_create.attach_type != BPF_PERF_EVENT && - attr->link_create.attach_type != BPF_TRACE_KPROBE_MULTI) { - ret = -EINVAL; - goto out; - } - break; - case BPF_PROG_TYPE_SCHED_CLS: - if (attr->link_create.attach_type != BPF_TCX_INGRESS && - attr->link_create.attach_type != BPF_TCX_EGRESS) { - ret = -EINVAL; - goto out; - } - break; - default: - ptype = attach_type_to_prog_type(attr->link_create.attach_type); - if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) { - ret = -EINVAL; - goto out; - } - break; - } - - switch (prog->type) { case BPF_PROG_TYPE_CGROUP_SKB: case BPF_PROG_TYPE_CGROUP_SOCK: case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: -- 2.7.4