Patch "ipv4: fix data-races around inet->inet_id" has been added to the 6.4-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This is a note to let you know that I've just added the patch titled

    ipv4: fix data-races around inet->inet_id

to the 6.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ipv4-fix-data-races-around-inet-inet_id.patch
and it can be found in the queue-6.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 5fc1939a7228d769ce7570979667fb75d525d6d3
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date:   Sat Aug 19 03:17:07 2023 +0000

    ipv4: fix data-races around inet->inet_id
    
    [ Upstream commit f866fbc842de5976e41ba874b76ce31710b634b5 ]
    
    UDP sendmsg() is lockless, so ip_select_ident_segs()
    can very well be run from multiple cpus [1]
    
    Convert inet->inet_id to an atomic_t, but implement
    a dedicated path for TCP, avoiding cost of a locked
    instruction (atomic_add_return())
    
    Note that this patch will cause a trivial merge conflict
    because we added inet->flags in net-next tree.
    
    v2: added missing change in
    drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c
    (David Ahern)
    
    [1]
    
    BUG: KCSAN: data-race in __ip_make_skb / __ip_make_skb
    
    read-write to 0xffff888145af952a of 2 bytes by task 7803 on cpu 1:
    ip_select_ident_segs include/net/ip.h:542 [inline]
    ip_select_ident include/net/ip.h:556 [inline]
    __ip_make_skb+0x844/0xc70 net/ipv4/ip_output.c:1446
    ip_make_skb+0x233/0x2c0 net/ipv4/ip_output.c:1560
    udp_sendmsg+0x1199/0x1250 net/ipv4/udp.c:1260
    inet_sendmsg+0x63/0x80 net/ipv4/af_inet.c:830
    sock_sendmsg_nosec net/socket.c:725 [inline]
    sock_sendmsg net/socket.c:748 [inline]
    ____sys_sendmsg+0x37c/0x4d0 net/socket.c:2494
    ___sys_sendmsg net/socket.c:2548 [inline]
    __sys_sendmmsg+0x269/0x500 net/socket.c:2634
    __do_sys_sendmmsg net/socket.c:2663 [inline]
    __se_sys_sendmmsg net/socket.c:2660 [inline]
    __x64_sys_sendmmsg+0x57/0x60 net/socket.c:2660
    do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
    entry_SYSCALL_64_after_hwframe+0x63/0xcd
    
    read to 0xffff888145af952a of 2 bytes by task 7804 on cpu 0:
    ip_select_ident_segs include/net/ip.h:541 [inline]
    ip_select_ident include/net/ip.h:556 [inline]
    __ip_make_skb+0x817/0xc70 net/ipv4/ip_output.c:1446
    ip_make_skb+0x233/0x2c0 net/ipv4/ip_output.c:1560
    udp_sendmsg+0x1199/0x1250 net/ipv4/udp.c:1260
    inet_sendmsg+0x63/0x80 net/ipv4/af_inet.c:830
    sock_sendmsg_nosec net/socket.c:725 [inline]
    sock_sendmsg net/socket.c:748 [inline]
    ____sys_sendmsg+0x37c/0x4d0 net/socket.c:2494
    ___sys_sendmsg net/socket.c:2548 [inline]
    __sys_sendmmsg+0x269/0x500 net/socket.c:2634
    __do_sys_sendmmsg net/socket.c:2663 [inline]
    __se_sys_sendmmsg net/socket.c:2660 [inline]
    __x64_sys_sendmmsg+0x57/0x60 net/socket.c:2660
    do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
    entry_SYSCALL_64_after_hwframe+0x63/0xcd
    
    value changed: 0x184d -> 0x184e
    
    Reported by Kernel Concurrency Sanitizer on:
    CPU: 0 PID: 7804 Comm: syz-executor.1 Not tainted 6.5.0-rc6-syzkaller #0
    Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
    ==================================================================
    
    Fixes: 23f57406b82d ("ipv4: avoid using shared IP generator for connected sockets")
    Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
    Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
    Reviewed-by: David Ahern <dsahern@xxxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c
index c2e7037c7ba1c..7750702900fa6 100644
--- a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c
+++ b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c
@@ -1466,7 +1466,7 @@ static void make_established(struct sock *sk, u32 snd_isn, unsigned int opt)
 	tp->write_seq = snd_isn;
 	tp->snd_nxt = snd_isn;
 	tp->snd_una = snd_isn;
-	inet_sk(sk)->inet_id = get_random_u16();
+	atomic_set(&inet_sk(sk)->inet_id, get_random_u16());
 	assign_rxopt(sk, opt);
 
 	if (tp->rcv_wnd > (RCV_BUFSIZ_M << 10))
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 0bb32bfc61832..491ceb7ebe5d1 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -222,8 +222,8 @@ struct inet_sock {
 	__s16			uc_ttl;
 	__u16			cmsg_flags;
 	struct ip_options_rcu __rcu	*inet_opt;
+	atomic_t		inet_id;
 	__be16			inet_sport;
-	__u16			inet_id;
 
 	__u8			tos;
 	__u8			min_ttl;
diff --git a/include/net/ip.h b/include/net/ip.h
index 530e7257e4389..1872f570abeda 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -532,8 +532,19 @@ static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
 	 * generator as much as we can.
 	 */
 	if (sk && inet_sk(sk)->inet_daddr) {
-		iph->id = htons(inet_sk(sk)->inet_id);
-		inet_sk(sk)->inet_id += segs;
+		int val;
+
+		/* avoid atomic operations for TCP,
+		 * as we hold socket lock at this point.
+		 */
+		if (sk_is_tcp(sk)) {
+			sock_owned_by_me(sk);
+			val = atomic_read(&inet_sk(sk)->inet_id);
+			atomic_set(&inet_sk(sk)->inet_id, val + segs);
+		} else {
+			val = atomic_add_return(segs, &inet_sk(sk)->inet_id);
+		}
+		iph->id = htons(val);
 		return;
 	}
 	if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 3ab68415d121c..e7b9703bd1a1a 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -130,7 +130,7 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 						    inet->inet_daddr,
 						    inet->inet_sport,
 						    inet->inet_dport);
-	inet->inet_id = get_random_u16();
+	atomic_set(&inet->inet_id, get_random_u16());
 
 	err = dccp_connect(sk);
 	rt = NULL;
@@ -432,7 +432,7 @@ struct sock *dccp_v4_request_recv_sock(const struct sock *sk,
 	RCU_INIT_POINTER(newinet->inet_opt, rcu_dereference(ireq->ireq_opt));
 	newinet->mc_index  = inet_iif(skb);
 	newinet->mc_ttl	   = ip_hdr(skb)->ttl;
-	newinet->inet_id   = get_random_u16();
+	atomic_set(&newinet->inet_id, get_random_u16());
 
 	if (dst == NULL && (dst = inet_csk_route_child_sock(sk, newsk, req)) == NULL)
 		goto put_and_exit;
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 10ebe39dcc873..9dde8e842befe 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -340,7 +340,7 @@ static int inet_create(struct net *net, struct socket *sock, int protocol,
 	else
 		inet->pmtudisc = IP_PMTUDISC_WANT;
 
-	inet->inet_id = 0;
+	atomic_set(&inet->inet_id, 0);
 
 	sock_init_data(sock, sk);
 
diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
index 4d1af0cd7d99e..cb5dbee9e018f 100644
--- a/net/ipv4/datagram.c
+++ b/net/ipv4/datagram.c
@@ -73,7 +73,7 @@ int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len
 	reuseport_has_conns_set(sk);
 	sk->sk_state = TCP_ESTABLISHED;
 	sk_set_txhash(sk);
-	inet->inet_id = get_random_u16();
+	atomic_set(&inet->inet_id, get_random_u16());
 
 	sk_dst_set(sk, &rt->dst);
 	err = 0;
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 498dd4acdeec8..caecb4d1e424a 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -312,7 +312,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 					     inet->inet_daddr));
 	}
 
-	inet->inet_id = get_random_u16();
+	atomic_set(&inet->inet_id, get_random_u16());
 
 	if (tcp_fastopen_defer_connect(sk, &err))
 		return err;
@@ -1596,7 +1596,7 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
 	inet_csk(newsk)->icsk_ext_hdr_len = 0;
 	if (inet_opt)
 		inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
-	newinet->inet_id = get_random_u16();
+	atomic_set(&newinet->inet_id, get_random_u16());
 
 	/* Set ToS of the new socket based upon the value of incoming SYN.
 	 * ECT bits are set later in tcp_init_transfer().
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index de52045774303..d77561d97a1ed 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -9479,7 +9479,7 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk,
 	newinet->inet_rcv_saddr = inet->inet_rcv_saddr;
 	newinet->inet_dport = htons(asoc->peer.port);
 	newinet->pmtudisc = inet->pmtudisc;
-	newinet->inet_id = get_random_u16();
+	atomic_set(&newinet->inet_id, get_random_u16());
 
 	newinet->uc_ttl = inet->uc_ttl;
 	newinet->mc_loop = 1;



[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux