| Message ID | 20240515073644.32503-3-yenchia.chen@mediatek.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | netlink, fix issues caught by syzbot | expand |
On Wed, May 15, 2024 at 03:36:38PM +0800, Yenchia Chen wrote: > From: Eric Dumazet <edumazet@google.com> > > syzbot caught another data-race in netlink when > setting sk->sk_err. > > Annotate all of them for good measure. > > BUG: KCSAN: data-race in netlink_recvmsg / netlink_recvmsg > > write to 0xffff8881613bb220 of 4 bytes by task 28147 on cpu 0: > netlink_recvmsg+0x448/0x780 net/netlink/af_netlink.c:1994 > sock_recvmsg_nosec net/socket.c:1027 [inline] > sock_recvmsg net/socket.c:1049 [inline] > __sys_recvfrom+0x1f4/0x2e0 net/socket.c:2229 > __do_sys_recvfrom net/socket.c:2247 [inline] > __se_sys_recvfrom net/socket.c:2243 [inline] > __x64_sys_recvfrom+0x78/0x90 net/socket.c:2243 > 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 > > write to 0xffff8881613bb220 of 4 bytes by task 28146 on cpu 1: > netlink_recvmsg+0x448/0x780 net/netlink/af_netlink.c:1994 > sock_recvmsg_nosec net/socket.c:1027 [inline] > sock_recvmsg net/socket.c:1049 [inline] > __sys_recvfrom+0x1f4/0x2e0 net/socket.c:2229 > __do_sys_recvfrom net/socket.c:2247 [inline] > __se_sys_recvfrom net/socket.c:2243 [inline] > __x64_sys_recvfrom+0x78/0x90 net/socket.c:2243 > 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 -> 0x00000016 > > Reported by Kernel Concurrency Sanitizer on: > CPU: 1 PID: 28146 Comm: syz-executor.0 Not tainted 6.6.0-rc3-syzkaller-00055-g9ed22ae6be81 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Signed-off-by: Eric Dumazet <edumazet@google.com> > Reported-by: syzbot <syzkaller@googlegroups.com> > Reviewed-by: Simon Horman <horms@kernel.org> > Link: https://lore.kernel.org/r/20231003183455.3410550-1-edumazet@google.com > Signed-off-by: Jakub Kicinski <kuba@kernel.org> > Signed-off-by: yenchia.chen <yenchia.chen@mediatek.com> > --- The conflict resolution looks good to me, thanks! Reviewed-by: Carlos Llamas <cmllamas@google.com>
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 56ba8a6396ca..216445dd44db 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -352,7 +352,7 @@ static void netlink_overrun(struct sock *sk) if (!(nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)) { if (!test_and_set_bit(NETLINK_S_CONGESTED, &nlk_sk(sk)->state)) { - sk->sk_err = ENOBUFS; + WRITE_ONCE(sk->sk_err, ENOBUFS); sk_error_report(sk); } } @@ -1591,7 +1591,7 @@ static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) goto out; } - sk->sk_err = p->code; + WRITE_ONCE(sk->sk_err, p->code); sk_error_report(sk); out: return ret; @@ -2006,7 +2006,7 @@ static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { ret = netlink_dump(sk); if (ret) { - sk->sk_err = -ret; + WRITE_ONCE(sk->sk_err, -ret); sk_error_report(sk); } } @@ -2442,7 +2442,7 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, skb = nlmsg_new(payload + tlvlen, GFP_KERNEL); if (!skb) { - NETLINK_CB(in_skb).sk->sk_err = ENOBUFS; + WRITE_ONCE(NETLINK_CB(in_skb).sk->sk_err, ENOBUFS); sk_error_report(NETLINK_CB(in_skb).sk); return; }