From 38207a5e81230d6ffbdd51e5fa5681be5116dcae Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Fri, 19 Nov 2021 10:14:17 -0800 Subject: bpf, sockmap: Attach map progs to psock early for feature probes When a TCP socket is added to a sock map we look at the programs attached to the map to determine what proto op hooks need to be changed. Before the patch in the 'fixes' tag there were only two categories -- the empty set of programs or a TX policy. In any case the base set handled the receive case. After the fix we have an optimized program for receive that closes a small, but possible, race on receive. This program is loaded only when the map the psock is being added to includes a RX policy. Otherwise, the race is not possible so we don't need to handle the race condition. In order for the call to sk_psock_init() to correctly evaluate the above conditions all progs need to be set in the psock before the call. However, in the current code this is not the case. We end up evaluating the requirements on the old prog state. If your psock is attached to multiple maps -- for example a tx map and rx map -- then the second update would pull in the correct maps. But, the other pattern with a single rx enabled map the correct receive hooks are not used. The result is the race fixed by the patch in the fixes tag below may still be seen in this case. To fix we simply set all psock->progs before doing the call into sock_map_init(). With this the init() call gets the full list of programs and chooses the correct proto ops on the first iteration instead of requiring the second update to pull them in. This fixes the race case when only a single map is used. Fixes: c5d2177a72a16 ("bpf, sockmap: Fix race in ingress receive verdict with redirect to self") Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20211119181418.353932-2-john.fastabend@gmail.com --- net/core/sock_map.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'net/core') diff --git a/net/core/sock_map.c b/net/core/sock_map.c index f39ef79ced67..9b528c644fb7 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -282,6 +282,12 @@ static int sock_map_link(struct bpf_map *map, struct sock *sk) if (msg_parser) psock_set_prog(&psock->progs.msg_parser, msg_parser); + if (stream_parser) + psock_set_prog(&psock->progs.stream_parser, stream_parser); + if (stream_verdict) + psock_set_prog(&psock->progs.stream_verdict, stream_verdict); + if (skb_verdict) + psock_set_prog(&psock->progs.skb_verdict, skb_verdict); ret = sock_map_init_proto(sk, psock); if (ret < 0) @@ -292,14 +298,10 @@ static int sock_map_link(struct bpf_map *map, struct sock *sk) ret = sk_psock_init_strp(sk, psock); if (ret) goto out_unlock_drop; - psock_set_prog(&psock->progs.stream_verdict, stream_verdict); - psock_set_prog(&psock->progs.stream_parser, stream_parser); sk_psock_start_strp(sk, psock); } else if (!stream_parser && stream_verdict && !psock->saved_data_ready) { - psock_set_prog(&psock->progs.stream_verdict, stream_verdict); sk_psock_start_verdict(sk,psock); } else if (!stream_verdict && skb_verdict && !psock->saved_data_ready) { - psock_set_prog(&psock->progs.skb_verdict, skb_verdict); sk_psock_start_verdict(sk, psock); } write_unlock_bh(&sk->sk_callback_lock); -- cgit v1.2.3 From c0d95d3380ee099d735e08618c0d599e72f6c8b0 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Fri, 19 Nov 2021 10:14:18 -0800 Subject: bpf, sockmap: Re-evaluate proto ops when psock is removed from sockmap When a sock is added to a sock map we evaluate what proto op hooks need to be used. However, when the program is removed from the sock map we have not been evaluating if that changes the required program layout. Before the patch listed in the 'fixes' tag this was not causing failures because the base program set handles all cases. Specifically, the case with a stream parser and the case with out a stream parser are both handled. With the fix below we identified a race when running with a proto op that attempts to read skbs off both the stream parser and the skb->receive_queue. Namely, that a race existed where when the stream parser is empty checking the skb->receive_queue from recvmsg at the precies moment when the parser is paused and the receive_queue is not empty could result in skipping the stream parser. This may break a RX policy depending on the parser to run. The fix tag then loads a specific proto ops that resolved this race. But, we missed removing that proto ops recv hook when the sock is removed from the sockmap. The result is the stream parser is stopped so no more skbs will be aggregated there, but the hook and BPF program continues to be attached on the psock. User space will then get an EBUSY when trying to read the socket because the recvmsg() handler is now waiting on a stopped stream parser. To fix we rerun the proto ops init() function which will look at the new set of progs attached to the psock and rest the proto ops hook to the correct handlers. And in the above case where we remove the sock from the sock map the RX prog will no longer be listed so the proto ops is removed. Fixes: c5d2177a72a16 ("bpf, sockmap: Fix race in ingress receive verdict with redirect to self") Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20211119181418.353932-3-john.fastabend@gmail.com --- net/core/skmsg.c | 5 +++++ net/core/sock_map.c | 5 ++++- 2 files changed, 9 insertions(+), 1 deletion(-) (limited to 'net/core') diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 1ae52ac943f6..8eb671c827f9 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -1124,6 +1124,8 @@ void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock) void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock) { + psock_set_prog(&psock->progs.stream_parser, NULL); + if (!psock->saved_data_ready) return; @@ -1212,6 +1214,9 @@ void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock) void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock) { + psock_set_prog(&psock->progs.stream_verdict, NULL); + psock_set_prog(&psock->progs.skb_verdict, NULL); + if (!psock->saved_data_ready) return; diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 9b528c644fb7..4ca4b11f4e5f 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -167,8 +167,11 @@ static void sock_map_del_link(struct sock *sk, write_lock_bh(&sk->sk_callback_lock); if (strp_stop) sk_psock_stop_strp(sk, psock); - else + if (verdict_stop) sk_psock_stop_verdict(sk, psock); + + if (psock->psock_update_sk_prot) + psock->psock_update_sk_prot(sk, psock, false); write_unlock_bh(&sk->sk_callback_lock); } } -- cgit v1.2.3 From 4dbb0dad8e63fcd0b5a117c2861d2abe7ff5f186 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 5 Dec 2021 11:28:22 -0800 Subject: devlink: fix netns refcount leak in devlink_nl_cmd_reload() While preparing my patch series adding netns refcount tracking, I spotted bugs in devlink_nl_cmd_reload() Some error paths forgot to release a refcount on a netns. To fix this, we can reduce the scope of get_net()/put_net() section around the call to devlink_reload(). Fixes: ccdf07219da6 ("devlink: Add reload action option to devlink reload command") Fixes: dc64cc7c6310 ("devlink: Add devlink reload limit option") Signed-off-by: Eric Dumazet Cc: Moshe Shemesh Cc: Jacob Keller Cc: Jiri Pirko Reviewed-by: Leon Romanovsky Link: https://lore.kernel.org/r/20211205192822.1741045-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski --- net/core/devlink.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'net/core') diff --git a/net/core/devlink.c b/net/core/devlink.c index 5ad72dbfcd07..c06c9ba6e8c5 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -4110,14 +4110,6 @@ static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info) return err; } - if (info->attrs[DEVLINK_ATTR_NETNS_PID] || - info->attrs[DEVLINK_ATTR_NETNS_FD] || - info->attrs[DEVLINK_ATTR_NETNS_ID]) { - dest_net = devlink_netns_get(skb, info); - if (IS_ERR(dest_net)) - return PTR_ERR(dest_net); - } - if (info->attrs[DEVLINK_ATTR_RELOAD_ACTION]) action = nla_get_u8(info->attrs[DEVLINK_ATTR_RELOAD_ACTION]); else @@ -4160,6 +4152,14 @@ static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info) return -EINVAL; } } + if (info->attrs[DEVLINK_ATTR_NETNS_PID] || + info->attrs[DEVLINK_ATTR_NETNS_FD] || + info->attrs[DEVLINK_ATTR_NETNS_ID]) { + dest_net = devlink_netns_get(skb, info); + if (IS_ERR(dest_net)) + return PTR_ERR(dest_net); + } + err = devlink_reload(devlink, dest_net, action, limit, &actions_performed, info->extack); if (dest_net) -- cgit v1.2.3 From e195e9b5dee6459d8c8e6a314cc71a644a0537fd Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 6 Dec 2021 08:53:29 -0800 Subject: net, neigh: clear whole pneigh_entry at alloc time Commit 2c611ad97a82 ("net, neigh: Extend neigh->flags to 32 bit to allow for extensions") enables a new KMSAM warning [1] I think the bug is actually older, because the following intruction only occurred if ndm->ndm_flags had NTF_PROXY set. pn->flags = ndm->ndm_flags; Let's clear all pneigh_entry fields at alloc time. [1] BUG: KMSAN: uninit-value in pneigh_fill_info+0x986/0xb30 net/core/neighbour.c:2593 pneigh_fill_info+0x986/0xb30 net/core/neighbour.c:2593 pneigh_dump_table net/core/neighbour.c:2715 [inline] neigh_dump_info+0x1e3f/0x2c60 net/core/neighbour.c:2832 netlink_dump+0xaca/0x16a0 net/netlink/af_netlink.c:2265 __netlink_dump_start+0xd1c/0xee0 net/netlink/af_netlink.c:2370 netlink_dump_start include/linux/netlink.h:254 [inline] rtnetlink_rcv_msg+0x181b/0x18c0 net/core/rtnetlink.c:5534 netlink_rcv_skb+0x447/0x800 net/netlink/af_netlink.c:2491 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5589 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x1095/0x1360 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x16f3/0x1870 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] sock_write_iter+0x594/0x690 net/socket.c:1057 call_write_iter include/linux/fs.h:2162 [inline] new_sync_write fs/read_write.c:503 [inline] vfs_write+0x1318/0x2030 fs/read_write.c:590 ksys_write+0x28c/0x520 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0xdb/0x120 fs/read_write.c:652 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was created at: slab_post_alloc_hook mm/slab.h:524 [inline] slab_alloc_node mm/slub.c:3251 [inline] slab_alloc mm/slub.c:3259 [inline] __kmalloc+0xc3c/0x12d0 mm/slub.c:4437 kmalloc include/linux/slab.h:595 [inline] pneigh_lookup+0x60f/0xd70 net/core/neighbour.c:766 arp_req_set_public net/ipv4/arp.c:1016 [inline] arp_req_set+0x430/0x10a0 net/ipv4/arp.c:1032 arp_ioctl+0x8d4/0xb60 net/ipv4/arp.c:1232 inet_ioctl+0x4ef/0x820 net/ipv4/af_inet.c:947 sock_do_ioctl net/socket.c:1118 [inline] sock_ioctl+0xa3f/0x13e0 net/socket.c:1235 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0x2df/0x4a0 fs/ioctl.c:860 __x64_sys_ioctl+0xd8/0x110 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae CPU: 1 PID: 20001 Comm: syz-executor.0 Not tainted 5.16.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 62dd93181aaa ("[IPV6] NDISC: Set per-entry is_router flag in Proxy NA.") Signed-off-by: Eric Dumazet Cc: Roopa Prabhu Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20211206165329.1049835-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski --- net/core/neighbour.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'net/core') diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 72ba027c34cf..dda12fbd177b 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -763,11 +763,10 @@ struct pneigh_entry * pneigh_lookup(struct neigh_table *tbl, ASSERT_RTNL(); - n = kmalloc(sizeof(*n) + key_len, GFP_KERNEL); + n = kzalloc(sizeof(*n) + key_len, GFP_KERNEL); if (!n) goto out; - n->protocol = 0; write_pnet(&n->net, net); memcpy(n->key, pkey, key_len); n->dev = dev; -- cgit v1.2.3