When bpf program calling bpf_setsockopt(SOL_SOCKET),
it could be run in softirq and doesn't make sense to do the capable
check. There was a similar situation in bpf_setsockopt(TCP_CONGESTION).
In commit 8d650cdedaab ("tcp: fix tcp_set_congestion_control() use from bpf hook"),
tcp_set_congestion_control(..., cap_net_admin) was added to skip
the cap check for bpf prog.
This patch adds sockopt_ns_capable() and sockopt_capable() for
the sk_setsockopt() to use. They will consider the
has_current_bpf_ctx() before doing the ns_capable() and capable() test.
They are in EXPORT_SYMBOL for the ipv6 module to use in a latter patch.
Suggested-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
Signed-off-by: Martin KaFai Lau <kafai@xxxxxx>
---
include/net/sock.h | 2 ++
net/core/sock.c | 38 +++++++++++++++++++++++++-------------
2 files changed, 27 insertions(+), 13 deletions(-)
diff --git a/include/net/sock.h b/include/net/sock.h
index b2ff230860c6..72b78c2b6f83 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1723,6 +1723,8 @@ static inline void unlock_sock_fast(struct sock *sk, bool slow)
void sockopt_lock_sock(struct sock *sk);
void sockopt_release_sock(struct sock *sk);
+bool sockopt_ns_capable(struct user_namespace *ns, int cap);
+bool sockopt_capable(int cap);
/* Used by processes to "lock" a socket state, so that
* interrupts and bottom half handlers won't change it
diff --git a/net/core/sock.c b/net/core/sock.c
index d3683228376f..7ea46e4700fd 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1060,6 +1060,18 @@ void sockopt_release_sock(struct sock *sk)
}
EXPORT_SYMBOL(sockopt_release_sock);
+bool sockopt_ns_capable(struct user_namespace *ns, int cap)
+{
+ return has_current_bpf_ctx() || ns_capable(ns, cap);
+}
+EXPORT_SYMBOL(sockopt_ns_capable);
+
+bool sockopt_capable(int cap)
+{
+ return has_current_bpf_ctx() || capable(cap);
+}
+EXPORT_SYMBOL(sockopt_capable);
+
/*
* This is meant for all protocols to use and covers goings on
* at the socket level. Everything here is generic.
@@ -1095,7 +1107,7 @@ static int sk_setsockopt(struct sock *sk, int level, int optname,
switch (optname) {
case SO_DEBUG:
- if (val && !capable(CAP_NET_ADMIN))
+ if (val && !sockopt_capable(CAP_NET_ADMIN))
ret = -EACCES;
else
sock_valbool_flag(sk, SOCK_DBG, valbool);
@@ -1139,7 +1151,7 @@ static int sk_setsockopt(struct sock *sk, int level, int optname,
break;
case SO_SNDBUFFORCE:
- if (!capable(CAP_NET_ADMIN)) {
+ if (!sockopt_capable(CAP_NET_ADMIN)) {
ret = -EPERM;
break;
}
@@ -1161,7 +1173,7 @@ static int sk_setsockopt(struct sock *sk, int level, int optname,
break;
case SO_RCVBUFFORCE:
- if (!capable(CAP_NET_ADMIN)) {
+ if (!sockopt_capable(CAP_NET_ADMIN)) {
ret = -EPERM;
break;
}
@@ -1188,8 +1200,8 @@ static int sk_setsockopt(struct sock *sk, int level, int optname,
case SO_PRIORITY:
if ((val >= 0 && val <= 6) ||
- ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
- ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
+ sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
+ sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
sk->sk_priority = val;
else
ret = -EPERM;
@@ -1334,8 +1346,8 @@ static int sk_setsockopt(struct sock *sk, int level, int optname,
clear_bit(SOCK_PASSSEC, &sock->flags);
break;
case SO_MARK:
- if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
- !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
+ if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
+ !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
ret = -EPERM;
break;
}
@@ -1343,8 +1355,8 @@ static int sk_setsockopt(struct sock *sk, int level, int optname,
__sock_set_mark(sk, val);
break;
case SO_RCVMARK:
- if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
- !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
+ if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
+ !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
ret = -EPERM;
break;
}
@@ -1378,7 +1390,7 @@ static int sk_setsockopt(struct sock *sk, int level, int optname,
#ifdef CONFIG_NET_RX_BUSY_POLL
case SO_BUSY_POLL:
/* allow unprivileged users to decrease the value */
- if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
+ if ((val > sk->sk_ll_usec) && !sockopt_capable(CAP_NET_ADMIN))
ret = -EPERM;
else {
if (val < 0)
@@ -1388,13 +1400,13 @@ static int sk_setsockopt(struct sock *sk, int level, int optname,
}
break;
case SO_PREFER_BUSY_POLL:
- if (valbool && !capable(CAP_NET_ADMIN))
+ if (valbool && !sockopt_capable(CAP_NET_ADMIN))
ret = -EPERM;
else
WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
break;
case SO_BUSY_POLL_BUDGET:
- if (val > READ_ONCE(sk->sk_busy_poll_budget) && !capable(CAP_NET_ADMIN)) {
+ if (val > READ_ONCE(sk->sk_busy_poll_budget) && !sockopt_capable(CAP_NET_ADMIN)) {
ret = -EPERM;
} else {
if (val < 0 || val > U16_MAX)
@@ -1465,7 +1477,7 @@ static int sk_setsockopt(struct sock *sk, int level, int optname,
* scheduler has enough safe guards.
*/
if (sk_txtime.clockid != CLOCK_MONOTONIC &&
- !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
+ !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
ret = -EPERM;
break;
}
--
2.30.2
