From: Eric Dumazet edumazet@google.com
[ Upstream commit 9ed498c6280a2f2b51d02df96df53037272ede49 ]
sk->sk_backlog.tail might be read without holding the socket spinlock, we need to add proper READ_ONCE()/WRITE_ONCE() to silence the warnings.
KCSAN reported :
BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg
write to 0xffff8881265109f8 of 8 bytes by interrupt on cpu 1: __sk_add_backlog include/net/sock.h:907 [inline] sk_add_backlog include/net/sock.h:938 [inline] tcp_add_backlog+0x476/0xce0 net/ipv4/tcp_ipv4.c:1759 tcp_v4_rcv+0x1a70/0x1bd0 net/ipv4/tcp_ipv4.c:1947 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:4929 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5043 netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5133 napi_skb_finish net/core/dev.c:5596 [inline] napi_gro_receive+0x28f/0x330 net/core/dev.c:5629 receive_buf+0x284/0x30b0 drivers/net/virtio_net.c:1061 virtnet_receive drivers/net/virtio_net.c:1323 [inline] virtnet_poll+0x436/0x7d0 drivers/net/virtio_net.c:1428 napi_poll net/core/dev.c:6311 [inline] net_rx_action+0x3ae/0xa90 net/core/dev.c:6379 __do_softirq+0x115/0x33f kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0xbb/0xe0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] do_IRQ+0xa6/0x180 arch/x86/kernel/irq.c:263 ret_from_intr+0x0/0x19 native_safe_halt+0xe/0x10 arch/x86/kernel/paravirt.c:71 arch_cpu_idle+0x1f/0x30 arch/x86/kernel/process.c:571 default_idle_call+0x1e/0x40 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x1af/0x280 kernel/sched/idle.c:263 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:355 start_secondary+0x208/0x260 arch/x86/kernel/smpboot.c:264 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241
read to 0xffff8881265109f8 of 8 bytes by task 8057 on cpu 0: tcp_recvmsg+0x46e/0x1b40 net/ipv4/tcp.c:2050 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838 sock_recvmsg_nosec net/socket.c:871 [inline] sock_recvmsg net/socket.c:889 [inline] sock_recvmsg+0x92/0xb0 net/socket.c:885 sock_read_iter+0x15f/0x1e0 net/socket.c:967 call_read_iter include/linux/fs.h:1889 [inline] new_sync_read+0x389/0x4f0 fs/read_write.c:414 __vfs_read+0xb1/0xc0 fs/read_write.c:427 vfs_read fs/read_write.c:461 [inline] vfs_read+0x143/0x2c0 fs/read_write.c:446 ksys_read+0xd5/0x1b0 fs/read_write.c:587 __do_sys_read fs/read_write.c:597 [inline] __se_sys_read fs/read_write.c:595 [inline] __x64_sys_read+0x4c/0x60 fs/read_write.c:595 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: 0 PID: 8057 Comm: syz-fuzzer Not tainted 5.4.0-rc6+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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 --- drivers/crypto/chelsio/chtls/chtls_io.c | 10 +++++----- include/net/sock.h | 4 ++-- net/ipv4/tcp.c | 2 +- net/llc/af_llc.c | 2 +- 4 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/crypto/chelsio/chtls/chtls_io.c b/drivers/crypto/chelsio/chtls/chtls_io.c index ce1f1d5d7cd5a..c403d6b64e087 100644 --- a/drivers/crypto/chelsio/chtls/chtls_io.c +++ b/drivers/crypto/chelsio/chtls/chtls_io.c @@ -1437,7 +1437,7 @@ static int chtls_pt_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, csk->wr_max_credits)) sk->sk_write_space(sk);
- if (copied >= target && !sk->sk_backlog.tail) + if (copied >= target && !READ_ONCE(sk->sk_backlog.tail)) break;
if (copied) { @@ -1470,7 +1470,7 @@ static int chtls_pt_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, break; } } - if (sk->sk_backlog.tail) { + if (READ_ONCE(sk->sk_backlog.tail)) { release_sock(sk); lock_sock(sk); chtls_cleanup_rbuf(sk, copied); @@ -1615,7 +1615,7 @@ static int peekmsg(struct sock *sk, struct msghdr *msg, break; }
- if (sk->sk_backlog.tail) { + if (READ_ONCE(sk->sk_backlog.tail)) { /* Do not sleep, just process backlog. */ release_sock(sk); lock_sock(sk); @@ -1743,7 +1743,7 @@ int chtls_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, csk->wr_max_credits)) sk->sk_write_space(sk);
- if (copied >= target && !sk->sk_backlog.tail) + if (copied >= target && !READ_ONCE(sk->sk_backlog.tail)) break;
if (copied) { @@ -1774,7 +1774,7 @@ int chtls_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, } }
- if (sk->sk_backlog.tail) { + if (READ_ONCE(sk->sk_backlog.tail)) { release_sock(sk); lock_sock(sk); chtls_cleanup_rbuf(sk, copied); diff --git a/include/net/sock.h b/include/net/sock.h index 6d9c1131fe5c8..e6a48ebb22aa4 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -909,11 +909,11 @@ static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb) skb_dst_force(skb);
if (!sk->sk_backlog.tail) - sk->sk_backlog.head = skb; + WRITE_ONCE(sk->sk_backlog.head, skb); else sk->sk_backlog.tail->next = skb;
- sk->sk_backlog.tail = skb; + WRITE_ONCE(sk->sk_backlog.tail, skb); skb->next = NULL; }
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 01ddfb4156e4a..2ffa33b5ef404 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2053,7 +2053,7 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
/* Well, if we have backlog, try to process it now yet. */
- if (copied >= target && !sk->sk_backlog.tail) + if (copied >= target && !READ_ONCE(sk->sk_backlog.tail)) break;
if (copied) { diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c index 5abb7f9b7ee5f..fa0f3c1543ba5 100644 --- a/net/llc/af_llc.c +++ b/net/llc/af_llc.c @@ -784,7 +784,7 @@ static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, } /* Well, if we have backlog, try to process it now yet. */
- if (copied >= target && !sk->sk_backlog.tail) + if (copied >= target && !READ_ONCE(sk->sk_backlog.tail)) break;
if (copied) {