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net: inet: diag: expose the socket mark to privileged processes.
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This adds the capability for a process that has CAP_NET_ADMIN on
a socket to see the socket mark in socket dumps.

Commit a52e95a ("net: diag: allow socket bytecode filters to
match socket marks") recently gave privileged processes the
ability to filter socket dumps based on mark. This patch is
complementary: it ensures that the mark is also passed to
userspace in the socket's netlink attributes.  It is useful for
tools like ss which display information about sockets.

Tested: https://android-review.googlesource.com/270210
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Lorenzo Colitti authored and David S. Miller committed Sep 8, 2016
1 parent 74f13c8 commit d545cac
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Showing 5 changed files with 56 additions and 28 deletions.
4 changes: 2 additions & 2 deletions include/linux/inet_diag.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -37,7 +37,7 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
struct sk_buff *skb, const struct inet_diag_req_v2 *req,
struct user_namespace *user_ns,
u32 pid, u32 seq, u16 nlmsg_flags,
const struct nlmsghdr *unlh);
const struct nlmsghdr *unlh, bool net_admin);
void inet_diag_dump_icsk(struct inet_hashinfo *h, struct sk_buff *skb,
struct netlink_callback *cb,
const struct inet_diag_req_v2 *r,
Expand All @@ -56,7 +56,7 @@ void inet_diag_msg_common_fill(struct inet_diag_msg *r, struct sock *sk);

int inet_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb,
struct inet_diag_msg *r, int ext,
struct user_namespace *user_ns);
struct user_namespace *user_ns, bool net_admin);

extern int inet_diag_register(const struct inet_diag_handler *handler);
extern void inet_diag_unregister(const struct inet_diag_handler *handler);
Expand Down
1 change: 1 addition & 0 deletions include/uapi/linux/inet_diag.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -123,6 +123,7 @@ enum {
INET_DIAG_LOCALS,
INET_DIAG_PEERS,
INET_DIAG_PAD,
INET_DIAG_MARK,
__INET_DIAG_MAX,
};

Expand Down
49 changes: 33 additions & 16 deletions net/ipv4/inet_diag.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -99,6 +99,7 @@ static size_t inet_sk_attr_size(void)
+ nla_total_size(1) /* INET_DIAG_SHUTDOWN */
+ nla_total_size(1) /* INET_DIAG_TOS */
+ nla_total_size(1) /* INET_DIAG_TCLASS */
+ nla_total_size(4) /* INET_DIAG_MARK */
+ nla_total_size(sizeof(struct inet_diag_meminfo))
+ nla_total_size(sizeof(struct inet_diag_msg))
+ nla_total_size(SK_MEMINFO_VARS * sizeof(u32))
Expand All @@ -109,7 +110,8 @@ static size_t inet_sk_attr_size(void)

int inet_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb,
struct inet_diag_msg *r, int ext,
struct user_namespace *user_ns)
struct user_namespace *user_ns,
bool net_admin)
{
const struct inet_sock *inet = inet_sk(sk);

Expand All @@ -136,6 +138,9 @@ int inet_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb,
}
#endif

if (net_admin && nla_put_u32(skb, INET_DIAG_MARK, sk->sk_mark))
goto errout;

r->idiag_uid = from_kuid_munged(user_ns, sock_i_uid(sk));
r->idiag_inode = sock_i_ino(sk);

Expand All @@ -149,7 +154,8 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
struct sk_buff *skb, const struct inet_diag_req_v2 *req,
struct user_namespace *user_ns,
u32 portid, u32 seq, u16 nlmsg_flags,
const struct nlmsghdr *unlh)
const struct nlmsghdr *unlh,
bool net_admin)
{
const struct tcp_congestion_ops *ca_ops;
const struct inet_diag_handler *handler;
Expand All @@ -175,7 +181,7 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
r->idiag_timer = 0;
r->idiag_retrans = 0;

if (inet_diag_msg_attrs_fill(sk, skb, r, ext, user_ns))
if (inet_diag_msg_attrs_fill(sk, skb, r, ext, user_ns, net_admin))
goto errout;

if (ext & (1 << (INET_DIAG_MEMINFO - 1))) {
Expand Down Expand Up @@ -274,10 +280,11 @@ static int inet_csk_diag_fill(struct sock *sk,
const struct inet_diag_req_v2 *req,
struct user_namespace *user_ns,
u32 portid, u32 seq, u16 nlmsg_flags,
const struct nlmsghdr *unlh)
const struct nlmsghdr *unlh,
bool net_admin)
{
return inet_sk_diag_fill(sk, inet_csk(sk), skb, req,
user_ns, portid, seq, nlmsg_flags, unlh);
return inet_sk_diag_fill(sk, inet_csk(sk), skb, req, user_ns,
portid, seq, nlmsg_flags, unlh, net_admin);
}

static int inet_twsk_diag_fill(struct sock *sk,
Expand Down Expand Up @@ -319,8 +326,9 @@ static int inet_twsk_diag_fill(struct sock *sk,

static int inet_req_diag_fill(struct sock *sk, struct sk_buff *skb,
u32 portid, u32 seq, u16 nlmsg_flags,
const struct nlmsghdr *unlh)
const struct nlmsghdr *unlh, bool net_admin)
{
struct request_sock *reqsk = inet_reqsk(sk);
struct inet_diag_msg *r;
struct nlmsghdr *nlh;
long tmo;
Expand All @@ -334,7 +342,7 @@ static int inet_req_diag_fill(struct sock *sk, struct sk_buff *skb,
inet_diag_msg_common_fill(r, sk);
r->idiag_state = TCP_SYN_RECV;
r->idiag_timer = 1;
r->idiag_retrans = inet_reqsk(sk)->num_retrans;
r->idiag_retrans = reqsk->num_retrans;

BUILD_BUG_ON(offsetof(struct inet_request_sock, ir_cookie) !=
offsetof(struct sock, sk_cookie));
Expand All @@ -346,6 +354,10 @@ static int inet_req_diag_fill(struct sock *sk, struct sk_buff *skb,
r->idiag_uid = 0;
r->idiag_inode = 0;

if (net_admin && nla_put_u32(skb, INET_DIAG_MARK,
inet_rsk(reqsk)->ir_mark))
return -EMSGSIZE;

nlmsg_end(skb, nlh);
return 0;
}
Expand All @@ -354,18 +366,18 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
const struct inet_diag_req_v2 *r,
struct user_namespace *user_ns,
u32 portid, u32 seq, u16 nlmsg_flags,
const struct nlmsghdr *unlh)
const struct nlmsghdr *unlh, bool net_admin)
{
if (sk->sk_state == TCP_TIME_WAIT)
return inet_twsk_diag_fill(sk, skb, portid, seq,
nlmsg_flags, unlh);

if (sk->sk_state == TCP_NEW_SYN_RECV)
return inet_req_diag_fill(sk, skb, portid, seq,
nlmsg_flags, unlh);
nlmsg_flags, unlh, net_admin);

return inet_csk_diag_fill(sk, skb, r, user_ns, portid, seq,
nlmsg_flags, unlh);
nlmsg_flags, unlh, net_admin);
}

struct sock *inet_diag_find_one_icsk(struct net *net,
Expand Down Expand Up @@ -435,7 +447,8 @@ int inet_diag_dump_one_icsk(struct inet_hashinfo *hashinfo,
err = sk_diag_fill(sk, rep, req,
sk_user_ns(NETLINK_CB(in_skb).sk),
NETLINK_CB(in_skb).portid,
nlh->nlmsg_seq, 0, nlh);
nlh->nlmsg_seq, 0, nlh,
netlink_net_capable(in_skb, CAP_NET_ADMIN));
if (err < 0) {
WARN_ON(err == -EMSGSIZE);
nlmsg_free(rep);
Expand Down Expand Up @@ -796,15 +809,17 @@ static int inet_csk_diag_dump(struct sock *sk,
struct sk_buff *skb,
struct netlink_callback *cb,
const struct inet_diag_req_v2 *r,
const struct nlattr *bc)
const struct nlattr *bc,
bool net_admin)
{
if (!inet_diag_bc_sk(bc, sk))
return 0;

return inet_csk_diag_fill(sk, skb, r,
sk_user_ns(NETLINK_CB(cb->skb).sk),
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh,
net_admin);
}

static void twsk_build_assert(void)
Expand Down Expand Up @@ -840,6 +855,7 @@ void inet_diag_dump_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *skb,
struct net *net = sock_net(skb->sk);
int i, num, s_i, s_num;
u32 idiag_states = r->idiag_states;
bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);

if (idiag_states & TCPF_SYN_RECV)
idiag_states |= TCPF_NEW_SYN_RECV;
Expand Down Expand Up @@ -880,7 +896,8 @@ void inet_diag_dump_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *skb,
cb->args[3] > 0)
goto next_listen;

if (inet_csk_diag_dump(sk, skb, cb, r, bc) < 0) {
if (inet_csk_diag_dump(sk, skb, cb, r,
bc, net_admin) < 0) {
spin_unlock_bh(&ilb->lock);
goto done;
}
Expand Down Expand Up @@ -948,7 +965,7 @@ void inet_diag_dump_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *skb,
sk_user_ns(NETLINK_CB(cb->skb).sk),
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
cb->nlh);
cb->nlh, net_admin);
if (res < 0) {
spin_unlock_bh(lock);
goto done;
Expand Down
10 changes: 6 additions & 4 deletions net/ipv4/udp_diag.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -20,15 +20,15 @@
static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
struct netlink_callback *cb,
const struct inet_diag_req_v2 *req,
struct nlattr *bc)
struct nlattr *bc, bool net_admin)
{
if (!inet_diag_bc_sk(bc, sk))
return 0;

return inet_sk_diag_fill(sk, NULL, skb, req,
sk_user_ns(NETLINK_CB(cb->skb).sk),
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh, net_admin);
}

static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
Expand Down Expand Up @@ -76,7 +76,8 @@ static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
err = inet_sk_diag_fill(sk, NULL, rep, req,
sk_user_ns(NETLINK_CB(in_skb).sk),
NETLINK_CB(in_skb).portid,
nlh->nlmsg_seq, 0, nlh);
nlh->nlmsg_seq, 0, nlh,
netlink_net_capable(in_skb, CAP_NET_ADMIN));
if (err < 0) {
WARN_ON(err == -EMSGSIZE);
kfree_skb(rep);
Expand All @@ -97,6 +98,7 @@ static void udp_dump(struct udp_table *table, struct sk_buff *skb,
struct netlink_callback *cb,
const struct inet_diag_req_v2 *r, struct nlattr *bc)
{
bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
struct net *net = sock_net(skb->sk);
int num, s_num, slot, s_slot;

Expand Down Expand Up @@ -132,7 +134,7 @@ static void udp_dump(struct udp_table *table, struct sk_buff *skb,
r->id.idiag_dport)
goto next;

if (sk_diag_dump(sk, skb, cb, r, bc) < 0) {
if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0) {
spin_unlock_bh(&hslot->lock);
goto done;
}
Expand Down
20 changes: 14 additions & 6 deletions net/sctp/sctp_diag.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -106,7 +106,8 @@ static int inet_sctp_diag_fill(struct sock *sk, struct sctp_association *asoc,
const struct inet_diag_req_v2 *req,
struct user_namespace *user_ns,
int portid, u32 seq, u16 nlmsg_flags,
const struct nlmsghdr *unlh)
const struct nlmsghdr *unlh,
bool net_admin)
{
struct sctp_endpoint *ep = sctp_sk(sk)->ep;
struct list_head *addr_list;
Expand All @@ -133,7 +134,7 @@ static int inet_sctp_diag_fill(struct sock *sk, struct sctp_association *asoc,
r->idiag_retrans = 0;
}

if (inet_diag_msg_attrs_fill(sk, skb, r, ext, user_ns))
if (inet_diag_msg_attrs_fill(sk, skb, r, ext, user_ns, net_admin))
goto errout;

if (ext & (1 << (INET_DIAG_SKMEMINFO - 1))) {
Expand Down Expand Up @@ -203,6 +204,7 @@ struct sctp_comm_param {
struct netlink_callback *cb;
const struct inet_diag_req_v2 *r;
const struct nlmsghdr *nlh;
bool net_admin;
};

static size_t inet_assoc_attr_size(struct sctp_association *asoc)
Expand All @@ -219,6 +221,7 @@ static size_t inet_assoc_attr_size(struct sctp_association *asoc)
+ nla_total_size(1) /* INET_DIAG_SHUTDOWN */
+ nla_total_size(1) /* INET_DIAG_TOS */
+ nla_total_size(1) /* INET_DIAG_TCLASS */
+ nla_total_size(4) /* INET_DIAG_MARK */
+ nla_total_size(addrlen * asoc->peer.transport_count)
+ nla_total_size(addrlen * addrcnt)
+ nla_total_size(sizeof(struct inet_diag_meminfo))
Expand Down Expand Up @@ -256,7 +259,8 @@ static int sctp_tsp_dump_one(struct sctp_transport *tsp, void *p)
err = inet_sctp_diag_fill(sk, assoc, rep, req,
sk_user_ns(NETLINK_CB(in_skb).sk),
NETLINK_CB(in_skb).portid,
nlh->nlmsg_seq, 0, nlh);
nlh->nlmsg_seq, 0, nlh,
commp->net_admin);
release_sock(sk);
if (err < 0) {
WARN_ON(err == -EMSGSIZE);
Expand Down Expand Up @@ -310,7 +314,8 @@ static int sctp_tsp_dump(struct sctp_transport *tsp, void *p)
sk_user_ns(NETLINK_CB(cb->skb).sk),
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
NLM_F_MULTI, cb->nlh) < 0) {
NLM_F_MULTI, cb->nlh,
commp->net_admin) < 0) {
cb->args[3] = 1;
err = 2;
goto release;
Expand All @@ -320,7 +325,8 @@ static int sctp_tsp_dump(struct sctp_transport *tsp, void *p)
if (inet_sctp_diag_fill(sk, assoc, skb, r,
sk_user_ns(NETLINK_CB(cb->skb).sk),
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, 0, cb->nlh) < 0) {
cb->nlh->nlmsg_seq, 0, cb->nlh,
commp->net_admin) < 0) {
err = 2;
goto release;
}
Expand Down Expand Up @@ -375,7 +381,7 @@ static int sctp_ep_dump(struct sctp_endpoint *ep, void *p)
sk_user_ns(NETLINK_CB(cb->skb).sk),
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
cb->nlh) < 0) {
cb->nlh, commp->net_admin) < 0) {
err = 2;
goto out;
}
Expand Down Expand Up @@ -412,6 +418,7 @@ static int sctp_diag_dump_one(struct sk_buff *in_skb,
.skb = in_skb,
.r = req,
.nlh = nlh,
.net_admin = netlink_net_capable(in_skb, CAP_NET_ADMIN),
};

if (req->sdiag_family == AF_INET) {
Expand Down Expand Up @@ -447,6 +454,7 @@ static void sctp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
.skb = skb,
.cb = cb,
.r = r,
.net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN),
};

/* eps hashtable dumps
Expand Down

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