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From: Sasha Levin <sashal@kernel•org>
To: linux-kernel@vger•kernel.org, stable@vger•kernel.org
Cc: Eric Dumazet <edumazet@google•com>,
	syzbot <syzkaller@googlegroups•com>,
	"David S . Miller" <davem@davemloft•net>,
	Sasha Levin <sashal@kernel•org>,
	yoshfuji@linux-ipv6•org, dsahern@kernel•org, kuba@kernel•org,
	pabeni@redhat•com, netdev@vger•kernel.org
Subject: [PATCH AUTOSEL 5.17 082/149] ipv6: annotate some data-races around sk->sk_prot
Date: Fri,  1 Apr 2022 10:24:29 -0400	[thread overview]
Message-ID: <20220401142536.1948161-82-sashal@kernel.org> (raw)
In-Reply-To: <20220401142536.1948161-1-sashal@kernel.org>

From: Eric Dumazet <edumazet@google•com>

[ Upstream commit 086d49058cd8471046ae9927524708820f5fd1c7 ]

IPv6 has this hack changing sk->sk_prot when an IPv6 socket
is 'converted' to an IPv4 one with IPV6_ADDRFORM option.

This operation is only performed for TCP and UDP, knowing
their 'struct proto' for the two network families are populated
in the same way, and can not disappear while a reader
might use and dereference sk->sk_prot.

If we think about it all reads of sk->sk_prot while
either socket lock or RTNL is not acquired should be using READ_ONCE().

Also note that other layers like MPTCP, XFRM, CHELSIO_TLS also
write over sk->sk_prot.

BUG: KCSAN: data-race in inet6_recvmsg / ipv6_setsockopt

write to 0xffff8881386f7aa8 of 8 bytes by task 26932 on cpu 0:
 do_ipv6_setsockopt net/ipv6/ipv6_sockglue.c:492 [inline]
 ipv6_setsockopt+0x3758/0x3910 net/ipv6/ipv6_sockglue.c:1019
 udpv6_setsockopt+0x85/0x90 net/ipv6/udp.c:1649
 sock_common_setsockopt+0x5d/0x70 net/core/sock.c:3489
 __sys_setsockopt+0x209/0x2a0 net/socket.c:2180
 __do_sys_setsockopt net/socket.c:2191 [inline]
 __se_sys_setsockopt net/socket.c:2188 [inline]
 __x64_sys_setsockopt+0x62/0x70 net/socket.c:2188
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881386f7aa8 of 8 bytes by task 26911 on cpu 1:
 inet6_recvmsg+0x7a/0x210 net/ipv6/af_inet6.c:659
 ____sys_recvmsg+0x16c/0x320
 ___sys_recvmsg net/socket.c:2674 [inline]
 do_recvmmsg+0x3f5/0xae0 net/socket.c:2768
 __sys_recvmmsg net/socket.c:2847 [inline]
 __do_sys_recvmmsg net/socket.c:2870 [inline]
 __se_sys_recvmmsg net/socket.c:2863 [inline]
 __x64_sys_recvmmsg+0xde/0x160 net/socket.c:2863
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffffffff85e0e980 -> 0xffffffff85e01580

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 26911 Comm: syz-executor.3 Not tainted 5.17.0-rc2-syzkaller-00316-g0457e5153e0e-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Reported-by: syzbot <syzkaller@googlegroups•com>
Signed-off-by: Eric Dumazet <edumazet@google•com>
Signed-off-by: David S. Miller <davem@davemloft•net>
Signed-off-by: Sasha Levin <sashal@kernel•org>
---
 net/ipv6/af_inet6.c      | 24 ++++++++++++++++++------
 net/ipv6/ipv6_sockglue.c |  6 ++++--
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 8fe7900f1949..7d7b7523d126 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -441,11 +441,14 @@ int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 {
 	struct sock *sk = sock->sk;
 	u32 flags = BIND_WITH_LOCK;
+	const struct proto *prot;
 	int err = 0;
 
+	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
+	prot = READ_ONCE(sk->sk_prot);
 	/* If the socket has its own bind function then use it. */
-	if (sk->sk_prot->bind)
-		return sk->sk_prot->bind(sk, uaddr, addr_len);
+	if (prot->bind)
+		return prot->bind(sk, uaddr, addr_len);
 
 	if (addr_len < SIN6_LEN_RFC2133)
 		return -EINVAL;
@@ -555,6 +558,7 @@ int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 	void __user *argp = (void __user *)arg;
 	struct sock *sk = sock->sk;
 	struct net *net = sock_net(sk);
+	const struct proto *prot;
 
 	switch (cmd) {
 	case SIOCADDRT:
@@ -572,9 +576,11 @@ int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 	case SIOCSIFDSTADDR:
 		return addrconf_set_dstaddr(net, argp);
 	default:
-		if (!sk->sk_prot->ioctl)
+		/* IPV6_ADDRFORM can change sk->sk_prot under us. */
+		prot = READ_ONCE(sk->sk_prot);
+		if (!prot->ioctl)
 			return -ENOIOCTLCMD;
-		return sk->sk_prot->ioctl(sk, cmd, arg);
+		return prot->ioctl(sk, cmd, arg);
 	}
 	/*NOTREACHED*/
 	return 0;
@@ -636,11 +642,14 @@ INDIRECT_CALLABLE_DECLARE(int udpv6_sendmsg(struct sock *, struct msghdr *,
 int inet6_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 {
 	struct sock *sk = sock->sk;
+	const struct proto *prot;
 
 	if (unlikely(inet_send_prepare(sk)))
 		return -EAGAIN;
 
-	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udpv6_sendmsg,
+	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
+	prot = READ_ONCE(sk->sk_prot);
+	return INDIRECT_CALL_2(prot->sendmsg, tcp_sendmsg, udpv6_sendmsg,
 			       sk, msg, size);
 }
 
@@ -650,13 +659,16 @@ int inet6_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 		  int flags)
 {
 	struct sock *sk = sock->sk;
+	const struct proto *prot;
 	int addr_len = 0;
 	int err;
 
 	if (likely(!(flags & MSG_ERRQUEUE)))
 		sock_rps_record_flow(sk);
 
-	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udpv6_recvmsg,
+	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
+	prot = READ_ONCE(sk->sk_prot);
+	err = INDIRECT_CALL_2(prot->recvmsg, tcp_recvmsg, udpv6_recvmsg,
 			      sk, msg, size, flags & MSG_DONTWAIT,
 			      flags & ~MSG_DONTWAIT, &addr_len);
 	if (err >= 0)
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index a733803a710c..222f6bf220ba 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -475,7 +475,8 @@ 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);
 
-				sk->sk_prot = &tcp_prot;
+				/* Paired with READ_ONCE(sk->sk_prot) in net/ipv6/af_inet6.c */
+				WRITE_ONCE(sk->sk_prot, &tcp_prot);
 				icsk->icsk_af_ops = &ipv4_specific;
 				sk->sk_socket->ops = &inet_stream_ops;
 				sk->sk_family = PF_INET;
@@ -489,7 +490,8 @@ 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);
 
-				sk->sk_prot = prot;
+				/* Paired with READ_ONCE(sk->sk_prot) in net/ipv6/af_inet6.c */
+				WRITE_ONCE(sk->sk_prot, prot);
 				sk->sk_socket->ops = &inet_dgram_ops;
 				sk->sk_family = PF_INET;
 			}
-- 
2.34.1


  parent reply	other threads:[~2022-04-01 14:34 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20220401142536.1948161-1-sashal@kernel.org>
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 002/149] Bluetooth: hci_sync: Fix compilation warning Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 003/149] ath5k: fix OOB in ath5k_eeprom_read_pcal_info_5111 Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 004/149] Bluetooth: fix null ptr deref on hci_sync_conn_complete_evt Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 009/149] Bluetooth: hci_event: Ignore multiple conn complete events Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 017/149] ptp: replace snprintf with sysfs_emit Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 018/149] Bluetooth: hci_sync: Fix queuing commands when HCI_UNREGISTER is set Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 019/149] selftests, xsk: Fix bpf_res cleanup test Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 020/149] net/mlx5e: TC, Hold sample_attr on stack instead of pointer Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 025/149] mlxsw: spectrum: Guard against invalid local ports Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 029/149] ath11k: fix kernel panic during unload/load ath11k modules Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 030/149] ath11k: pci: fix crash on suspend if board file is not found Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 031/149] ath11k: mhi: use mhi_sync_power_up() Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 032/149] net/smc: Send directly when TCP_CORK is cleared Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 034/149] bpf: Make dst_port field in struct bpf_sock 16-bit wide Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 039/149] mt76: mt7921: fix crash when startup fails Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 040/149] mt76: dma: initialize skip_unmap in mt76_dma_rx_fill Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 041/149] i40e: Add sending commands in atomic context Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 042/149] cfg80211: don't add non transmitted BSS to 6GHz scanned channels Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 043/149] libbpf: Fix build issue with llvm-readelf Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 044/149] ipv6: make mc_forwarding atomic Sasha Levin
2022-04-01 14:23 ` [PATCH AUTOSEL 5.17 046/149] net: initialize init_net earlier Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 060/149] libbpf: Fix accessing syscall arguments on powerpc Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 061/149] libbpf: Fix accessing the first syscall argument on arm64 Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 062/149] libbpf: Fix accessing the first syscall argument on s390 Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 064/149] tcp: Don't acquire inet_listen_hashbucket::lock with disabled BH Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 074/149] net/mlx5e: Disable TX queues before registering the netdev Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 078/149] iwlwifi: mvm: Correctly set fragmented EBS Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 079/149] iwlwifi: mvm: Passively scan non PSC channels only when requested so Sasha Levin
2022-04-01 14:52   ` Ben Greear
2022-04-09 14:04     ` Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 080/149] iwlwifi: fix small doc mistake for iwl_fw_ini_addr_val Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 081/149] iwlwifi: mvm: move only to an enabled channel Sasha Levin
2022-04-01 14:24 ` Sasha Levin [this message]
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 085/149] rtw89: fix RCU usage in rtw89_core_txq_push() Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 086/149] ath11k: Fix frames flush failure caused by deadlock Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 087/149] ipv4: Invalidate neighbour for broadcast address upon address addition Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 088/149] rtw88: change rtw_info() to proper message level Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 099/149] mt76: mt7915: fix injected MPDU transmission to not use HW A-MSDU Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 101/149] mctp: make __mctp_dev_get() take a refcount hold Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 103/149] mt76: mt7615: Fix assigning negative values to unsigned variable Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 109/149] net/smc: correct settings of RMB window update limit Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 111/149] iavf: stop leaking iavf_status as "errno" values Sasha Levin
2022-04-01 14:24 ` [PATCH AUTOSEL 5.17 112/149] macvtap: advertise link netns via netlink Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 114/149] tuntap: add sanity checks about msg_controllen in sendmsg Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 117/149] Bluetooth: Fix not checking for valid hdev on bt_dev_{info,warn,err,dbg} Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 118/149] Bluetooth: use memset avoid memory leaks Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 119/149] bnxt_en: Eliminate unintended link toggle during FW reset Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 123/149] powerpc/64e: Tie PPC_BOOK3E_64 to PPC_FSL_BOOK3E Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 127/149] can: isotp: set default value for N_As to 50 micro seconds Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 128/149] can: etas_es58x: es58x_fd_rx_event_msg(): initialize rx_event_msg before calling es58x_check_msg_len() Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 130/149] net: account alternate interface name memory Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 131/149] net: limit altnames to 64k total Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 132/149] net/mlx5e: Remove overzealous validations in netlink EEPROM query Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 135/149] net: sfp: add 2500base-X quirk for Lantech SFP module Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 138/149] mt76: fix monitor mode crash with sdio driver Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 140/149] iwlwifi: mei: fix building iwlmei Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 142/149] Bluetooth: Fix use after free in hci_send_acl Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 143/149] netfilter: conntrack: revisit gc autotuning Sasha Levin
2022-04-01 14:25 ` [PATCH AUTOSEL 5.17 144/149] netlabel: fix out-of-bounds memory accesses Sasha Levin

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