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Diffstat (limited to 'net/netlink/af_netlink.c')
-rw-r--r--net/netlink/af_netlink.c136
1 files changed, 59 insertions, 77 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 86b70385dce3..3808b12da7f6 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -156,7 +156,7 @@ static inline u32 netlink_group_mask(u32 group)
static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb,
gfp_t gfp_mask)
{
- unsigned int len = skb_end_offset(skb);
+ unsigned int len = skb->len;
struct sk_buff *new;
new = alloc_skb(len, gfp_mask);
@@ -365,7 +365,7 @@ static void netlink_skb_destructor(struct sk_buff *skb)
if (is_vmalloc_addr(skb->head)) {
if (!skb->cloned ||
!atomic_dec_return(&(skb_shinfo(skb)->dataref)))
- vfree(skb->head);
+ vfree_atomic(skb->head);
skb->head = NULL;
}
@@ -569,7 +569,9 @@ static int netlink_insert(struct sock *sk, u32 portid)
if (nlk_sk(sk)->bound)
goto err;
- nlk_sk(sk)->portid = portid;
+ /* portid can be read locklessly from netlink_getname(). */
+ WRITE_ONCE(nlk_sk(sk)->portid, portid);
+
sock_hold(sk);
err = __netlink_insert(table, sk);
@@ -1018,7 +1020,6 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr,
return -EINVAL;
}
- netlink_lock_table();
if (nlk->netlink_bind && groups) {
int group;
@@ -1030,13 +1031,14 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr,
if (!err)
continue;
netlink_undo_bind(group, groups, sk);
- goto unlock;
+ return err;
}
}
/* No need for barriers here as we return to user-space without
* using any of the bound attributes.
*/
+ netlink_lock_table();
if (!bound) {
err = nladdr->nl_pid ?
netlink_insert(sk, nladdr->nl_pid) :
@@ -1078,9 +1080,11 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
return -EINVAL;
if (addr->sa_family == AF_UNSPEC) {
- sk->sk_state = NETLINK_UNCONNECTED;
- nlk->dst_portid = 0;
- nlk->dst_group = 0;
+ /* paired with READ_ONCE() in netlink_getsockbyportid() */
+ WRITE_ONCE(sk->sk_state, NETLINK_UNCONNECTED);
+ /* dst_portid and dst_group can be read locklessly */
+ WRITE_ONCE(nlk->dst_portid, 0);
+ WRITE_ONCE(nlk->dst_group, 0);
return 0;
}
if (addr->sa_family != AF_NETLINK)
@@ -1101,9 +1105,11 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
err = netlink_autobind(sock);
if (err == 0) {
- sk->sk_state = NETLINK_CONNECTED;
- nlk->dst_portid = nladdr->nl_pid;
- nlk->dst_group = ffs(nladdr->nl_groups);
+ /* paired with READ_ONCE() in netlink_getsockbyportid() */
+ WRITE_ONCE(sk->sk_state, NETLINK_CONNECTED);
+ /* dst_portid and dst_group can be read locklessly */
+ WRITE_ONCE(nlk->dst_portid, nladdr->nl_pid);
+ WRITE_ONCE(nlk->dst_group, ffs(nladdr->nl_groups));
}
return err;
@@ -1120,10 +1126,12 @@ static int netlink_getname(struct socket *sock, struct sockaddr *addr,
nladdr->nl_pad = 0;
if (peer) {
- nladdr->nl_pid = nlk->dst_portid;
- nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
+ /* Paired with WRITE_ONCE() in netlink_connect() */
+ nladdr->nl_pid = READ_ONCE(nlk->dst_portid);
+ nladdr->nl_groups = netlink_group_mask(READ_ONCE(nlk->dst_group));
} else {
- nladdr->nl_pid = nlk->portid;
+ /* Paired with WRITE_ONCE() in netlink_insert() */
+ nladdr->nl_pid = READ_ONCE(nlk->portid);
netlink_lock_table();
nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
netlink_unlock_table();
@@ -1150,8 +1158,9 @@ static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid)
/* Don't bother queuing skb if kernel socket has no input function */
nlk = nlk_sk(sock);
- if (sock->sk_state == NETLINK_CONNECTED &&
- nlk->dst_portid != nlk_sk(ssk)->portid) {
+ /* dst_portid and sk_state can be changed in netlink_connect() */
+ if (READ_ONCE(sock->sk_state) == NETLINK_CONNECTED &&
+ READ_ONCE(nlk->dst_portid) != nlk_sk(ssk)->portid) {
sock_put(sock);
return ERR_PTR(-ECONNREFUSED);
}
@@ -1592,6 +1601,7 @@ out:
int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code)
{
struct netlink_set_err_data info;
+ unsigned long flags;
struct sock *sk;
int ret = 0;
@@ -1601,12 +1611,12 @@ int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code)
/* sk->sk_err wants a positive error value */
info.code = -code;
- read_lock(&nl_table_lock);
+ read_lock_irqsave(&nl_table_lock, flags);
sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list)
ret += do_one_set_err(sk, &info);
- read_unlock(&nl_table_lock);
+ read_unlock_irqrestore(&nl_table_lock, flags);
return ret;
}
EXPORT_SYMBOL(netlink_set_err);
@@ -1734,7 +1744,8 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname,
{
struct sock *sk = sock->sk;
struct netlink_sock *nlk = nlk_sk(sk);
- int len, val, err;
+ unsigned int flag;
+ int len, val;
if (level != SOL_NETLINK)
return -ENOPROTOOPT;
@@ -1746,39 +1757,17 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname,
switch (optname) {
case NETLINK_PKTINFO:
- if (len < sizeof(int))
- return -EINVAL;
- len = sizeof(int);
- val = nlk->flags & NETLINK_F_RECV_PKTINFO ? 1 : 0;
- if (put_user(len, optlen) ||
- put_user(val, optval))
- return -EFAULT;
- err = 0;
+ flag = NETLINK_F_RECV_PKTINFO;
break;
case NETLINK_BROADCAST_ERROR:
- if (len < sizeof(int))
- return -EINVAL;
- len = sizeof(int);
- val = nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR ? 1 : 0;
- if (put_user(len, optlen) ||
- put_user(val, optval))
- return -EFAULT;
- err = 0;
+ flag = NETLINK_F_BROADCAST_SEND_ERROR;
break;
case NETLINK_NO_ENOBUFS:
- if (len < sizeof(int))
- return -EINVAL;
- len = sizeof(int);
- val = nlk->flags & NETLINK_F_RECV_NO_ENOBUFS ? 1 : 0;
- if (put_user(len, optlen) ||
- put_user(val, optval))
- return -EFAULT;
- err = 0;
+ flag = NETLINK_F_RECV_NO_ENOBUFS;
break;
case NETLINK_LIST_MEMBERSHIPS: {
- int pos, idx, shift;
+ int pos, idx, shift, err = 0;
- err = 0;
netlink_lock_table();
for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) {
if (len - pos < sizeof(u32))
@@ -1792,43 +1781,35 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname,
break;
}
}
- if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen))
+ if (put_user(ALIGN(BITS_TO_BYTES(nlk->ngroups), sizeof(u32)), optlen))
err = -EFAULT;
netlink_unlock_table();
- break;
+ return err;
}
case NETLINK_CAP_ACK:
- if (len < sizeof(int))
- return -EINVAL;
- len = sizeof(int);
- val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0;
- if (put_user(len, optlen) ||
- put_user(val, optval))
- return -EFAULT;
- err = 0;
+ flag = NETLINK_F_CAP_ACK;
break;
case NETLINK_EXT_ACK:
- if (len < sizeof(int))
- return -EINVAL;
- len = sizeof(int);
- val = nlk->flags & NETLINK_F_EXT_ACK ? 1 : 0;
- if (put_user(len, optlen) || put_user(val, optval))
- return -EFAULT;
- err = 0;
+ flag = NETLINK_F_EXT_ACK;
break;
case NETLINK_GET_STRICT_CHK:
- if (len < sizeof(int))
- return -EINVAL;
- len = sizeof(int);
- val = nlk->flags & NETLINK_F_STRICT_CHK ? 1 : 0;
- if (put_user(len, optlen) || put_user(val, optval))
- return -EFAULT;
- err = 0;
+ flag = NETLINK_F_STRICT_CHK;
break;
default:
- err = -ENOPROTOOPT;
+ return -ENOPROTOOPT;
}
- return err;
+
+ if (len < sizeof(int))
+ return -EINVAL;
+
+ len = sizeof(int);
+ val = nlk->flags & flag ? 1 : 0;
+
+ if (put_user(len, optlen) ||
+ copy_to_user(optval, &val, len))
+ return -EFAULT;
+
+ return 0;
}
static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
@@ -1887,8 +1868,9 @@ static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
goto out;
netlink_skb_flags |= NETLINK_SKB_DST;
} else {
- dst_portid = nlk->dst_portid;
- dst_group = nlk->dst_group;
+ /* Paired with WRITE_ONCE() in netlink_connect() */
+ dst_portid = READ_ONCE(nlk->dst_portid);
+ dst_group = READ_ONCE(nlk->dst_group);
}
/* Paired with WRITE_ONCE() in netlink_insert() */
@@ -2010,7 +1992,7 @@ static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
skb_free_datagram(sk, skb);
- if (nlk->cb_running &&
+ if (READ_ONCE(nlk->cb_running) &&
atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
ret = netlink_dump(sk);
if (ret) {
@@ -2303,7 +2285,7 @@ static int netlink_dump(struct sock *sk)
if (cb->done)
cb->done(cb);
- nlk->cb_running = false;
+ WRITE_ONCE(nlk->cb_running, false);
module = cb->module;
skb = cb->skb;
mutex_unlock(nlk->cb_mutex);
@@ -2366,7 +2348,7 @@ int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
goto error_put;
}
- nlk->cb_running = true;
+ WRITE_ONCE(nlk->cb_running, true);
nlk->dump_done_errno = INT_MAX;
mutex_unlock(nlk->cb_mutex);
@@ -2655,7 +2637,7 @@ static int netlink_seq_show(struct seq_file *seq, void *v)
nlk->groups ? (u32)nlk->groups[0] : 0,
sk_rmem_alloc_get(s),
sk_wmem_alloc_get(s),
- nlk->cb_running,
+ READ_ONCE(nlk->cb_running),
refcount_read(&s->sk_refcnt),
atomic_read(&s->sk_drops),
sock_i_ino(s)
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-04-30 12:08:03 +0000