[PATCH 4.19 44/86] ipv4: raw: lock the socket in raw_bind()

Greg Kroah-Hartman
2022-02-07T11:25:11Z

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 153a0d187e767c68733b8e9f46218eb1f41ab902 ]

For some reason, raw_bind() forgot to lock the socket.

BUG: KCSAN: data-race in __ip4_datagram_connect / raw_bind

write to 0xffff8881170d4308 of 4 bytes by task 5466 on cpu 0:
raw_bind+0x1b0/0x250 net/ipv4/raw.c:739
inet_bind+0x56/0xa0 net/ipv4/af_inet.c:443
__sys_bind+0x14b/0x1b0 net/socket.c:1697
__do_sys_bind net/socket.c:1708 [inline]
__se_sys_bind net/socket.c:1706 [inline]
__x64_sys_bind+0x3d/0x50 net/socket.c:1706
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 0xffff8881170d4308 of 4 bytes by task 5468 on cpu 1:
__ip4_datagram_connect+0xb7/0x7b0 net/ipv4/datagram.c:39
ip4_datagram_connect+0x2a/0x40 net/ipv4/datagram.c:89
inet_dgram_connect+0x107/0x190 net/ipv4/af_inet.c:576
__sys_connect_file net/socket.c:1900 [inline]
__sys_connect+0x197/0x1b0 net/socket.c:1917
__do_sys_connect net/socket.c:1927 [inline]
__se_sys_connect net/socket.c:1924 [inline]
__x64_sys_connect+0x3d/0x50 net/socket.c:1924
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: 0x00000000 -> 0x0003007f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 5468 Comm: syz-executor.5 Not tainted 5.17.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
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: Sasha Levin <sashal@kernel.org>
---
net/ipv4/raw.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 21800979ed621..8cae691c3c9f4 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -725,6 +725,7 @@ static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
int ret = -EINVAL;
int chk_addr_ret;

+ lock_sock(sk);
if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_in))
goto out;

@@ -744,7 +745,9 @@ static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
inet->inet_saddr = 0; /* Use device */
sk_dst_reset(sk);
ret = 0;
-out: return ret;
+out:
+ release_sock(sk);
+ return ret;
}

/*
--
2.34.1