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ipv6: Fix data races around sk->sk_prot.

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commit 364f997b5cfe1db0d63a390fe7c801fa2b3115f6 upstream.

Commit 086d49058cd8 ("ipv6: annotate some data-races around sk->sk_prot")
fixed some data-races around sk->sk_prot but it was not enough.

Some functions in inet6_(stream|dgram)_ops still access sk->sk_prot
without lock_sock() or rtnl_lock(), so they need READ_ONCE() to avoid
load tearing.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Kazunori Kobayashi <kazunori.kobayashi@miraclelinux.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Kuniyuki Iwashima 2023-04-17 16:54:05 +00:00 committed by Greg Kroah-Hartman
parent 18560b76c7
commit f194e63054
3 changed files with 22 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
net/core/sock.c
View File

@ -3172,7 +3172,8 @@ int sock_common_getsockopt(struct socket *sock, int level, int optname,
{
struct sock *sk = sock->sk;
return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
/* IPV6_ADDRFORM can change sk->sk_prot under us. */
return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
}
EXPORT_SYMBOL(sock_common_getsockopt);
@ -3213,7 +3214,8 @@ int sock_common_setsockopt(struct socket *sock, int level, int optname,
{
struct sock *sk = sock->sk;
return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
/* IPV6_ADDRFORM can change sk->sk_prot under us. */
return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
}
EXPORT_SYMBOL(sock_common_setsockopt);

23
net/ipv4/af_inet.c
View File

@ -553,22 +553,27 @@ int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
int addr_len, int flags)
{
struct sock *sk = sock->sk;
const struct proto *prot;
int err;
if (addr_len < sizeof(uaddr->sa_family))
return -EINVAL;
/* IPV6_ADDRFORM can change sk->sk_prot under us. */
prot = READ_ONCE(sk->sk_prot);
if (uaddr->sa_family == AF_UNSPEC)
return sk->sk_prot->disconnect(sk, flags);
return prot->disconnect(sk, flags);
if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
err = prot->pre_connect(sk, uaddr, addr_len);
if (err)
return err;
}
if (!inet_sk(sk)->inet_num && inet_autobind(sk))
return -EAGAIN;
return sk->sk_prot->connect(sk, uaddr, addr_len);
return prot->connect(sk, uaddr, addr_len);
}
EXPORT_SYMBOL(inet_dgram_connect);
@ -731,10 +736,11 @@ EXPORT_SYMBOL(inet_stream_connect);
int inet_accept(struct socket *sock, struct socket *newsock, int flags,
bool kern)
{
struct sock *sk1 = sock->sk;
struct sock *sk1 = sock->sk, *sk2;
int err = -EINVAL;
struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err, kern);
/* IPV6_ADDRFORM can change sk->sk_prot under us. */
sk2 = READ_ONCE(sk1->sk_prot)->accept(sk1, flags, &err, kern);
if (!sk2)
goto do_err;
@ -815,12 +821,15 @@ ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
size_t size, int flags)
{
struct sock *sk = sock->sk;
const struct proto *prot;
if (unlikely(inet_send_prepare(sk)))
return -EAGAIN;
if (sk->sk_prot->sendpage)
return sk->sk_prot->sendpage(sk, page, offset, size, flags);
/* IPV6_ADDRFORM can change sk->sk_prot under us. */
prot = READ_ONCE(sk->sk_prot);
if (prot->sendpage)
return prot->sendpage(sk, page, offset, size, flags);
return sock_no_sendpage(sock, page, offset, size, flags);
}
EXPORT_SYMBOL(inet_sendpage);

4
net/ipv6/ipv6_sockglue.c
View File

@ -222,7 +222,7 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
sock_prot_inuse_add(net, sk->sk_prot, -1);
sock_prot_inuse_add(net, &tcp_prot, 1);
local_bh_enable();
/* Paired with READ_ONCE(sk->sk_prot) in net/ipv6/af_inet6.c */
/* Paired with READ_ONCE(sk->sk_prot) in inet6_stream_ops */
WRITE_ONCE(sk->sk_prot, &tcp_prot);
icsk->icsk_af_ops = &ipv4_specific;
sk->sk_socket->ops = &inet_stream_ops;
@ -237,7 +237,7 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
sock_prot_inuse_add(net, sk->sk_prot, -1);
sock_prot_inuse_add(net, prot, 1);
local_bh_enable();
/* Paired with READ_ONCE(sk->sk_prot) in net/ipv6/af_inet6.c */
/* Paired with READ_ONCE(sk->sk_prot) in inet6_dgram_ops */
WRITE_ONCE(sk->sk_prot, prot);
sk->sk_socket->ops = &inet_dgram_ops;
sk->sk_family = PF_INET;