linux-stable/net/unix
Eric Dumazet 35306eb238 af_unix: fix races in sk_peer_pid and sk_peer_cred accesses
Jann Horn reported that SO_PEERCRED and SO_PEERGROUPS implementations
are racy, as af_unix can concurrently change sk_peer_pid and sk_peer_cred.

In order to fix this issue, this patch adds a new spinlock that needs
to be used whenever these fields are read or written.

Jann also pointed out that l2cap_sock_get_peer_pid_cb() is currently
reading sk->sk_peer_pid which makes no sense, as this field
is only possibly set by AF_UNIX sockets.
We will have to clean this in a separate patch.
This could be done by reverting b48596d1dc "Bluetooth: L2CAP: Add get_peer_pid callback"
or implementing what was truly expected.

Fixes: 109f6e39fa ("af_unix: Allow SO_PEERCRED to work across namespaces.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-30 14:18:40 +01:00
..
af_unix.c af_unix: fix races in sk_peer_pid and sk_peer_cred accesses 2021-09-30 14:18:40 +01:00
diag.c net: Use nlmsg_unicast() instead of netlink_unicast() 2021-07-13 09:28:29 -07:00
garbage.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 62 2019-05-24 17:36:46 +02:00
Kconfig af_unix: Add OOB support 2021-08-04 09:55:52 +01:00
Makefile af_unix: Implement ->psock_update_sk_prot() 2021-07-15 18:17:50 -07:00
scm.c io_uring: move io_uring_get_socket() into io_uring.h 2020-09-30 20:32:33 -06:00
scm.h net: split out functions related to registering inflight socket files 2019-02-28 08:24:23 -07:00
sysctl_net_unix.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
unix_bpf.c af_unix: Add unix_stream_proto for sockmap 2021-08-16 18:43:39 -07:00