blob: 4a8758fbf03670ae93a54b0c29e708067fc02ce2 [file] [log] [blame]
From c7525fb562574bd8188e10179e281aec8338e0e4 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Wed, 23 Oct 2019 22:44:52 -0700
Subject: [PATCH] net: add READ_ONCE() annotation in
__skb_wait_for_more_packets()
commit 7c422d0ce97552dde4a97e6290de70ec6efb0fc6 upstream.
__skb_wait_for_more_packets() can be called while other cpus
can feed packets to the socket receive queue.
KCSAN reported :
BUG: KCSAN: data-race in __skb_wait_for_more_packets / __udp_enqueue_schedule_skb
write to 0xffff888102e40b58 of 8 bytes by interrupt on cpu 0:
__skb_insert include/linux/skbuff.h:1852 [inline]
__skb_queue_before include/linux/skbuff.h:1958 [inline]
__skb_queue_tail include/linux/skbuff.h:1991 [inline]
__udp_enqueue_schedule_skb+0x2d7/0x410 net/ipv4/udp.c:1470
__udp_queue_rcv_skb net/ipv4/udp.c:1940 [inline]
udp_queue_rcv_one_skb+0x7bd/0xc70 net/ipv4/udp.c:2057
udp_queue_rcv_skb+0xb5/0x400 net/ipv4/udp.c:2074
udp_unicast_rcv_skb.isra.0+0x7e/0x1c0 net/ipv4/udp.c:2233
__udp4_lib_rcv+0xa44/0x17c0 net/ipv4/udp.c:2300
udp_rcv+0x2b/0x40 net/ipv4/udp.c:2470
ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
NF_HOOK include/linux/netfilter.h:305 [inline]
NF_HOOK include/linux/netfilter.h:299 [inline]
ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
dst_input include/net/dst.h:442 [inline]
ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
NF_HOOK include/linux/netfilter.h:305 [inline]
NF_HOOK include/linux/netfilter.h:299 [inline]
ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
__netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
__netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
process_backlog+0x1d3/0x420 net/core/dev.c:5955
read to 0xffff888102e40b58 of 8 bytes by task 13035 on cpu 1:
__skb_wait_for_more_packets+0xfa/0x320 net/core/datagram.c:100
__skb_recv_udp+0x374/0x500 net/ipv4/udp.c:1683
udp_recvmsg+0xe1/0xb10 net/ipv4/udp.c:1712
inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838
sock_recvmsg_nosec+0x5c/0x70 net/socket.c:871
___sys_recvmsg+0x1a0/0x3e0 net/socket.c:2480
do_recvmmsg+0x19a/0x5c0 net/socket.c:2601
__sys_recvmmsg+0x1ef/0x200 net/socket.c:2680
__do_sys_recvmmsg net/socket.c:2703 [inline]
__se_sys_recvmmsg net/socket.c:2696 [inline]
__x64_sys_recvmmsg+0x89/0xb0 net/socket.c:2696
do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13035 Comm: syz-executor.3 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/net/core/datagram.c b/net/core/datagram.c
index b824b8117137..5dc112ec7286 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -97,7 +97,7 @@ int __skb_wait_for_more_packets(struct sock *sk, int *err, long *timeo_p,
if (error)
goto out_err;
- if (sk->sk_receive_queue.prev != skb)
+ if (READ_ONCE(sk->sk_receive_queue.prev) != skb)
goto out;
/* Socket shut down? */
--
2.7.4