summary refs log tree commit diff
path: root/net/tls/tls_main.c
diff options
context:
space:
mode:
authorEric Dumazet <edumazet@google.com>2023-05-09 18:29:48 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-05-24 17:32:32 +0100
commit65531f56753625527d2a47923896fc3e100ea497 (patch)
tree1b28059d0d645ff2063fb7bd0a26d9c6f706a57d /net/tls/tls_main.c
parentbd0f360ee86494037fbffcac28dbb47c438b33df (diff)
downloadlinux-65531f56753625527d2a47923896fc3e100ea497.tar.gz
net: deal with most data-races in sk_wait_event()
[ Upstream commit d0ac89f6f9879fae316c155de77b5173b3e2c9c9 ]

__condition is evaluated twice in sk_wait_event() macro.

First invocation is lockless, and reads can race with writes,
as spotted by syzbot.

BUG: KCSAN: data-race in sk_stream_wait_connect / tcp_disconnect

write to 0xffff88812d83d6a0 of 4 bytes by task 9065 on cpu 1:
tcp_disconnect+0x2cd/0xdb0
inet_shutdown+0x19e/0x1f0 net/ipv4/af_inet.c:911
__sys_shutdown_sock net/socket.c:2343 [inline]
__sys_shutdown net/socket.c:2355 [inline]
__do_sys_shutdown net/socket.c:2363 [inline]
__se_sys_shutdown+0xf8/0x140 net/socket.c:2361
__x64_sys_shutdown+0x31/0x40 net/socket.c:2361
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 0xffff88812d83d6a0 of 4 bytes by task 9040 on cpu 0:
sk_stream_wait_connect+0x1de/0x3a0 net/core/stream.c:75
tcp_sendmsg_locked+0x2e4/0x2120 net/ipv4/tcp.c:1266
tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1484
inet6_sendmsg+0x63/0x80 net/ipv6/af_inet6.c:651
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
__sys_sendto+0x246/0x300 net/socket.c:2142
__do_sys_sendto net/socket.c:2154 [inline]
__se_sys_sendto net/socket.c:2150 [inline]
__x64_sys_sendto+0x78/0x90 net/socket.c:2150
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: 0x00000000 -> 0x00000068

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
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>
Diffstat (limited to 'net/tls/tls_main.c')
-rw-r--r--net/tls/tls_main.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index b32c112984dd..f2e7302a4d96 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -111,7 +111,8 @@ int wait_on_pending_writer(struct sock *sk, long *timeo)
 			break;
 		}
 
-		if (sk_wait_event(sk, timeo, !sk->sk_write_pending, &wait))
+		if (sk_wait_event(sk, timeo,
+				  !READ_ONCE(sk->sk_write_pending), &wait))
 			break;
 	}
 	remove_wait_queue(sk_sleep(sk), &wait);