[PATCH bpf-next v2 01/28] bpf: add new is_sys_admin_prog_type() helper

From: Benjamin Tissoires
Date: Fri Mar 04 2022 - 12:30:44 EST


LIRC_MODE2 does not really need net_admin capability, but only sys_admin.

Extract a new helper for it, it will be also used for the HID bpf
implementation.

Cc: Sean Young <sean@xxxxxxxx>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>

---

new in v2
---
kernel/bpf/syscall.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index db402ebc5570..cc570891322b 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2165,7 +2165,6 @@ static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
case BPF_PROG_TYPE_LWT_SEG6LOCAL:
case BPF_PROG_TYPE_SK_SKB:
case BPF_PROG_TYPE_SK_MSG:
- case BPF_PROG_TYPE_LIRC_MODE2:
case BPF_PROG_TYPE_FLOW_DISSECTOR:
case BPF_PROG_TYPE_CGROUP_DEVICE:
case BPF_PROG_TYPE_CGROUP_SOCK:
@@ -2202,6 +2201,17 @@ static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
}
}

+static bool is_sys_admin_prog_type(enum bpf_prog_type prog_type)
+{
+ switch (prog_type) {
+ case BPF_PROG_TYPE_LIRC_MODE2:
+ case BPF_PROG_TYPE_EXT: /* extends any prog */
+ return true;
+ default:
+ return false;
+ }
+}
+
/* last field in 'union bpf_attr' used by this command */
#define BPF_PROG_LOAD_LAST_FIELD core_relo_rec_size

@@ -2252,6 +2262,8 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
return -EPERM;
if (is_perfmon_prog_type(type) && !perfmon_capable())
return -EPERM;
+ if (is_sys_admin_prog_type(type) && !capable(CAP_SYS_ADMIN))
+ return -EPERM;

/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
* or btf, we need to check which one it is
--
2.35.1