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* genetlink: hold RCU in genlmsg_mcast()Eric Dumazet2024-10-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While running net selftests with CONFIG_PROVE_RCU_LIST=y I saw one lockdep splat [1]. genlmsg_mcast() uses for_each_net_rcu(), and must therefore hold RCU. Instead of letting all callers guard genlmsg_multicast_allns() with a rcu_read_lock()/rcu_read_unlock() pair, do it in genlmsg_mcast(). This also means the @flags parameter is useless, we need to always use GFP_ATOMIC. [1] [10882.424136] ============================= [10882.424166] WARNING: suspicious RCU usage [10882.424309] 6.12.0-rc2-virtme #1156 Not tainted [10882.424400] ----------------------------- [10882.424423] net/netlink/genetlink.c:1940 RCU-list traversed in non-reader section!! [10882.424469] other info that might help us debug this: [10882.424500] rcu_scheduler_active = 2, debug_locks = 1 [10882.424744] 2 locks held by ip/15677: [10882.424791] #0: ffffffffb6b491b0 (cb_lock){++++}-{3:3}, at: genl_rcv (net/netlink/genetlink.c:1219) [10882.426334] #1: ffffffffb6b49248 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg (net/netlink/genetlink.c:61 net/netlink/genetlink.c:57 net/netlink/genetlink.c:1209) [10882.426465] stack backtrace: [10882.426805] CPU: 14 UID: 0 PID: 15677 Comm: ip Not tainted 6.12.0-rc2-virtme #1156 [10882.426919] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [10882.427046] Call Trace: [10882.427131] <TASK> [10882.427244] dump_stack_lvl (lib/dump_stack.c:123) [10882.427335] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) [10882.427387] genlmsg_multicast_allns (net/netlink/genetlink.c:1940 (discriminator 7) net/netlink/genetlink.c:1977 (discriminator 7)) [10882.427436] l2tp_tunnel_notify.constprop.0 (net/l2tp/l2tp_netlink.c:119) l2tp_netlink [10882.427683] l2tp_nl_cmd_tunnel_create (net/l2tp/l2tp_netlink.c:253) l2tp_netlink [10882.427748] genl_family_rcv_msg_doit (net/netlink/genetlink.c:1115) [10882.427834] genl_rcv_msg (net/netlink/genetlink.c:1195 net/netlink/genetlink.c:1210) [10882.427877] ? __pfx_l2tp_nl_cmd_tunnel_create (net/l2tp/l2tp_netlink.c:186) l2tp_netlink [10882.427927] ? __pfx_genl_rcv_msg (net/netlink/genetlink.c:1201) [10882.427959] netlink_rcv_skb (net/netlink/af_netlink.c:2551) [10882.428069] genl_rcv (net/netlink/genetlink.c:1220) [10882.428095] netlink_unicast (net/netlink/af_netlink.c:1332 net/netlink/af_netlink.c:1357) [10882.428140] netlink_sendmsg (net/netlink/af_netlink.c:1901) [10882.428210] ____sys_sendmsg (net/socket.c:729 (discriminator 1) net/socket.c:744 (discriminator 1) net/socket.c:2607 (discriminator 1)) Fixes: 33f72e6f0c67 ("l2tp : multicast notification to the registered listeners") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: James Chapman <jchapman@katalix.com> Cc: Tom Parkin <tparkin@katalix.com> Cc: Johannes Berg <johannes.berg@intel.com> Link: https://patch.msgid.link/20241011171217.3166614-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* l2tp: remove unneeded null check in l2tp_v2_session_get_nextJames Chapman2024-09-041-1/+1
| | | | | | | | | | | | | | | | | | | Commit aa92c1cec92b ("l2tp: add tunnel/session get_next helpers") uses idr_get_next APIs to iterate over l2tp session IDR lists. Sessions in l2tp_v2_session_idr always have a non-null session->tunnel pointer since l2tp_session_register sets it before inserting the session into the IDR. Therefore the null check on session->tunnel in l2tp_v2_session_get_next is redundant and can be removed. Removing the check avoids a warning from lkp. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/r/202408111407.HtON8jqa-lkp@intel.com/ CC: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: James Chapman <jchapman@katalix.com> Acked-by: Tom Parkin <tparkin@katalix.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20240903113547.1261048-1-jchapman@katalix.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* netdev_features: convert NETIF_F_LLTX to dev->lltxAlexander Lobakin2024-09-031-1/+1
| | | | | | | | | | NETIF_F_LLTX can't be changed via Ethtool and is not a feature, rather an attribute, very similar to IFF_NO_QUEUE (and hot). Free one netdev_features_t bit and make it a "hot" private flag. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
* l2tp: avoid using drain_workqueue in l2tp_pre_exit_netJames Chapman2024-08-271-6/+9
| | | | | | | | | | | | | | | | | | | | | Recent commit fc7ec7f554d7 ("l2tp: delete sessions using work queue") incorrectly uses drain_workqueue. The use of drain_workqueue in l2tp_pre_exit_net is flawed because the workqueue is shared by all nets and it is therefore possible for new work items to be queued for other nets while drain_workqueue runs. Instead of using drain_workqueue, use __flush_workqueue twice. The first one will run all tunnel delete work items and any work already queued. When tunnel delete work items are run, they may queue new session delete work items, which the second __flush_workqueue will run. In l2tp_exit_net, warn if any of the net's idr lists are not empty. Fixes: fc7ec7f554d7 ("l2tp: delete sessions using work queue") Signed-off-by: James Chapman <jchapman@katalix.com> Link: https://patch.msgid.link/20240823142257.692667-1-jchapman@katalix.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* l2tp: avoid overriding sk->sk_user_dataCong Wang2024-08-261-0/+3
| | | | | | | | | | | | | | | | | | Although commit 4a4cd70369f1 ("l2tp: don't set sk_user_data in tunnel socket") removed sk->sk_user_data usage, setup_udp_tunnel_sock() still touches sk->sk_user_data, this conflicts with sockmap which also leverages sk->sk_user_data to save psock. Restore this sk->sk_user_data check to avoid such conflicts. Fixes: 4a4cd70369f1 ("l2tp: don't set sk_user_data in tunnel socket") Reported-by: syzbot+8dbe3133b840c470da0e@syzkaller.appspotmail.com Cc: Tom Parkin <tparkin@katalix.com> Signed-off-by: Cong Wang <cong.wang@bytedance.com> Tested-by: James Chapman <jchapman@katalix.com> Reviewed-by: James Chapman <jchapman@katalix.com> Link: https://patch.msgid.link/20240822182544.378169-1-xiyou.wangcong@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* l2tp: use skb_queue_purge in l2tp_ip_destroy_sockJames Chapman2024-08-201-3/+1
| | | | | | | | | | | | | | | | | Recent commit ed8ebee6def7 ("l2tp: have l2tp_ip_destroy_sock use ip_flush_pending_frames") was incorrect in that l2tp_ip does not use socket cork and ip_flush_pending_frames is for sockets that do. Use __skb_queue_purge instead and remove the unnecessary lock. Also unexport ip_flush_pending_frames since it was originally exported in commit 4ff8863419cd ("ipv4: export ip_flush_pending_frames") for l2tp and is not used by other modules. Suggested-by: xiyou.wangcong@gmail.com Signed-off-by: James Chapman <jchapman@katalix.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240819143333.3204957-1-jchapman@katalix.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* l2tp: flush workqueue before draining itJames Chapman2024-08-111-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot exposes a race where a net used by l2tp is removed while an existing pppol2tp socket is closed. In l2tp_pre_exit_net, l2tp queues TUNNEL_DELETE work items to close each tunnel in the net. When these are run, new SESSION_DELETE work items are queued to delete each session in the tunnel. This all happens in drain_workqueue. However, drain_workqueue allows only new work items if they are queued by other work items which are already in the queue. If pppol2tp_release runs after drain_workqueue has started, it may queue a SESSION_DELETE work item, which results in the warning below in drain_workqueue. Address this by flushing the workqueue before drain_workqueue such that all queued TUNNEL_DELETE work items run before drain_workqueue is started. This will queue SESSION_DELETE work items for each session in the tunnel, hence pppol2tp_release or other API requests won't queue SESSION_DELETE requests once drain_workqueue is started. WARNING: CPU: 1 PID: 5467 at kernel/workqueue.c:2259 __queue_work+0xcd3/0xf50 kernel/workqueue.c:2258 Modules linked in: CPU: 1 UID: 0 PID: 5467 Comm: syz.3.43 Not tainted 6.11.0-rc1-syzkaller-00247-g3608d6aca5e7 #0 Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:__queue_work+0xcd3/0xf50 kernel/workqueue.c:2258 Code: ff e8 11 84 36 00 90 0f 0b 90 e9 1e fd ff ff e8 03 84 36 00 eb 13 e8 fc 83 36 00 eb 0c e8 f5 83 36 00 eb 05 e8 ee 83 36 00 90 <0f> 0b 90 48 83 c4 60 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc RSP: 0018:ffffc90004607b48 EFLAGS: 00010093 RAX: ffffffff815ce274 RBX: ffff8880661fda00 RCX: ffff8880661fda00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff815cd6d4 R09: 0000000000000000 R10: ffffc90004607c20 R11: fffff520008c0f85 R12: ffff88802ac33800 R13: ffff88802ac339c0 R14: dffffc0000000000 R15: 0000000000000008 FS: 00005555713eb500(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 000000001eda6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> queue_work_on+0x1c2/0x380 kernel/workqueue.c:2392 pppol2tp_release+0x163/0x230 net/l2tp/l2tp_ppp.c:445 __sock_release net/socket.c:659 [inline] sock_close+0xbc/0x240 net/socket.c:1421 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f061e9779f9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffff1c1fce8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000001017d RCX: 00007f061e9779f9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007ffff1c1fdc0 R08: 0000000000000001 R09: 00007ffff1c1ffcf R10: 00007f061e800000 R11: 0000000000000246 R12: 0000000000000032 R13: 00007ffff1c1fde0 R14: 00007ffff1c1fe00 R15: ffffffffffffffff </TASK> Fixes: fc7ec7f554d7 ("l2tp: delete sessions using work queue") Reported-by: syzbot+0e85b10481d2f5478053@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=0e85b10481d2f5478053 Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: l2tp_eth: use per-cpu counters from dev->tstatsJames Chapman2024-08-111-22/+10
| | | | | | | | | l2tp_eth uses old-style dev->stats for fastpath packet/byte counters. Convert it to use dev->tstats per-cpu counters. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: improve tunnel/session refcount helpersJames Chapman2024-08-118-93/+79
| | | | | | | | | | | | | | | l2tp_tunnel_inc_refcount and l2tp_session_inc_refcount wrap refcount_inc. They add no value so just use the refcount APIs directly and drop l2tp's helpers. l2tp already uses refcount_inc_not_zero anyway. Rename l2tp_tunnel_dec_refcount and l2tp_session_dec_refcount to l2tp_tunnel_put and l2tp_session_put to better match their use pairing various _get getters. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: use get_next APIs for management requests and procfs/debugfsJames Chapman2024-08-115-69/+39
| | | | | | | | | | | | | | | | l2tp netlink and procfs/debugfs iterate over tunnel and session lists to obtain data. They currently use very inefficient get_nth functions to do so. Replace these with get_next. For netlink, use nl cb->ctx[] for passing state instead of the obsolete cb->args[]. l2tp_tunnel_get_nth and l2tp_session_get_nth are no longer used so they can be removed. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: add tunnel/session get_next helpersJames Chapman2024-08-112-0/+129
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | l2tp management APIs and procfs/debugfs iterate over l2tp tunnel and session lists. Since these lists are now implemented using IDR, we can use IDR get_next APIs to iterate them. Add tunnel/session get_next functions to do so. The session get_next functions get the next session in a given tunnel and need to account for l2tpv2 and l2tpv3 differences: * l2tpv2 sessions are keyed by tunnel ID / session ID. Iteration for a given tunnel ID, TID, can therefore start with a key given by TID/0 and finish when the next entry's tunnel ID is not TID. This is possible only because the tunnel ID part of the key is the upper 16 bits and the session ID part the lower 16 bits; when idr_next increments the key value, it therefore finds the next sessions of the current tunnel before those of the next tunnel. Entries with session ID 0 are always skipped because they are used internally by pppol2tp. * l2tpv3 sessions are keyed by session ID. Iteration starts at the first IDR entry and skips entries where the tunnel does not match. Iteration must also consider session ID collisions and walk the list of colliding sessions (if any) for one which matches the supplied tunnel. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: handle hash key collisions in l2tp_v3_session_getJames Chapman2024-08-111-1/+2
| | | | | | | | | | | | To handle colliding l2tpv3 session IDs, l2tp_v3_session_get searches a hashed list keyed by ID and sk. Although unlikely, if hash keys collide, it is possible that hash_for_each_possible loops over a session which doesn't have the ID that we are searching for. So check for session ID match when looping over possible hash key matches. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: move l2tp_ip and l2tp_ip6 data to pernetJames Chapman2024-08-112-50/+168
| | | | | | | | | | | | l2tp_ip[6] have always used global socket tables. It is therefore not possible to create l2tpip sockets in different namespaces with the same socket address. To support this, move l2tpip socket tables to pernet data. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: remove inline from functions in c sourcesJames Chapman2024-08-114-6/+6
| | | | | | | | | Update l2tp to remove the inline keyword from several functions in C sources, since this is now discouraged. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2024-08-081-2/+13
|\ | | | | | | | | | | | | | | | | Cross-merge networking fixes after downstream PR. No conflicts or adjacent changes. Link: https://patch.msgid.link/20240808170148.3629934-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * l2tp: fix lockdep splatJames Chapman2024-08-081-2/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When l2tp tunnels use a socket provided by userspace, we can hit lockdep splats like the below when data is transmitted through another (unrelated) userspace socket which then gets routed over l2tp. This issue was previously discussed here: https://lore.kernel.org/netdev/87sfialu2n.fsf@cloudflare.com/ The solution is to have lockdep treat socket locks of l2tp tunnel sockets separately than those of standard INET sockets. To do so, use a different lockdep subclass where lock nesting is possible. ============================================ WARNING: possible recursive locking detected 6.10.0+ #34 Not tainted -------------------------------------------- iperf3/771 is trying to acquire lock: ffff8881027601d8 (slock-AF_INET/1){+.-.}-{2:2}, at: l2tp_xmit_skb+0x243/0x9d0 but task is already holding lock: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(slock-AF_INET/1); lock(slock-AF_INET/1); *** DEADLOCK *** May be due to missing lock nesting notation 10 locks held by iperf3/771: #0: ffff888102650258 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x1a/0x40 #1: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 #2: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 #3: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x28b/0x9f0 #4: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0xf9/0x260 #5: ffff888102650d98 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1848/0x1e10 #6: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: __ip_queue_xmit+0x4b/0xbc0 #7: ffffffff822ac220 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x17a/0x1130 #8: ffffffff822ac1e0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0xcc/0x1450 #9: ffff888101f33258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{2:2}, at: __dev_queue_xmit+0x513/0x1450 stack backtrace: CPU: 2 UID: 0 PID: 771 Comm: iperf3 Not tainted 6.10.0+ #34 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x69/0xa0 dump_stack+0xc/0x20 __lock_acquire+0x135d/0x2600 ? srso_alias_return_thunk+0x5/0xfbef5 lock_acquire+0xc4/0x2a0 ? l2tp_xmit_skb+0x243/0x9d0 ? __skb_checksum+0xa3/0x540 _raw_spin_lock_nested+0x35/0x50 ? l2tp_xmit_skb+0x243/0x9d0 l2tp_xmit_skb+0x243/0x9d0 l2tp_eth_dev_xmit+0x3c/0xc0 dev_hard_start_xmit+0x11e/0x420 sch_direct_xmit+0xc3/0x640 __dev_queue_xmit+0x61c/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 __tcp_send_ack+0x1b8/0x340 tcp_send_ack+0x23/0x30 __tcp_ack_snd_check+0xa8/0x530 ? srso_alias_return_thunk+0x5/0xfbef5 tcp_rcv_established+0x412/0xd70 tcp_v4_do_rcv+0x299/0x420 tcp_v4_rcv+0x1991/0x1e10 ip_protocol_deliver_rcu+0x50/0x220 ip_local_deliver_finish+0x158/0x260 ip_local_deliver+0xc8/0xe0 ip_rcv+0xe5/0x1d0 ? __pfx_ip_rcv+0x10/0x10 __netif_receive_skb_one_core+0xce/0xe0 ? process_backlog+0x28b/0x9f0 __netif_receive_skb+0x34/0xd0 ? process_backlog+0x28b/0x9f0 process_backlog+0x2cb/0x9f0 __napi_poll.constprop.0+0x61/0x280 net_rx_action+0x332/0x670 ? srso_alias_return_thunk+0x5/0xfbef5 ? find_held_lock+0x2b/0x80 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 handle_softirqs+0xda/0x480 ? __dev_queue_xmit+0xa2c/0x1450 do_softirq+0xa1/0xd0 </IRQ> <TASK> __local_bh_enable_ip+0xc8/0xe0 ? __dev_queue_xmit+0xa2c/0x1450 __dev_queue_xmit+0xa48/0x1450 ? ip_finish_output2+0xf4c/0x1130 ip_finish_output2+0x6b6/0x1130 ? srso_alias_return_thunk+0x5/0xfbef5 ? __ip_finish_output+0x217/0x380 ? srso_alias_return_thunk+0x5/0xfbef5 __ip_finish_output+0x217/0x380 ip_output+0x99/0x120 __ip_queue_xmit+0xae4/0xbc0 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? tcp_options_write.constprop.0+0xcb/0x3e0 ip_queue_xmit+0x34/0x40 __tcp_transmit_skb+0x1625/0x1890 tcp_write_xmit+0x766/0x2fb0 ? __entry_text_end+0x102ba9/0x102bad ? srso_alias_return_thunk+0x5/0xfbef5 ? __might_fault+0x74/0xc0 ? srso_alias_return_thunk+0x5/0xfbef5 __tcp_push_pending_frames+0x56/0x190 tcp_push+0x117/0x310 tcp_sendmsg_locked+0x14c1/0x1740 tcp_sendmsg+0x28/0x40 inet_sendmsg+0x5d/0x90 sock_write_iter+0x242/0x2b0 vfs_write+0x68d/0x800 ? __pfx_sock_write_iter+0x10/0x10 ksys_write+0xc8/0xf0 __x64_sys_write+0x3d/0x50 x64_sys_call+0xfaf/0x1f50 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f4d143af992 Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> e9 01 cc ff ff 41 54 b8 02 00 00 0 RSP: 002b:00007ffd65032058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f4d143af992 RDX: 0000000000000025 RSI: 00007f4d143f3bcc RDI: 0000000000000005 RBP: 00007f4d143f2b28 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d143f3bcc R13: 0000000000000005 R14: 0000000000000000 R15: 00007ffd650323f0 </TASK> Fixes: 0b2c59720e65 ("l2tp: close all race conditions in l2tp_tunnel_register()") Suggested-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot+6acef9e0a4d1f46c83d4@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=6acef9e0a4d1f46c83d4 CC: gnault@redhat.com CC: cong.wang@bytedance.com Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Link: https://patch.msgid.link/20240806160626.1248317-1-jchapman@katalix.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | l2tp: Don't assign net->gen->ptr[] for pppol2tp_net_ops.Kuniyuki Iwashima2024-08-031-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") converted net->gen->ptr[pppol2tp_net_id] in l2tp_ppp.c to net->gen->ptr[l2tp_net_id] in l2tp_core.c. Now the leftover wastes one entry of net->gen->ptr[] in each netns. Let's avoid the unwanted allocation. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | l2tp: use pre_exit pernet hook to avoid rcu_barrierJames Chapman2024-07-311-2/+7
| | | | | | | | | | | | | | | | | | | | Move the work of closing all tunnels from the pernet exit hook to pre_exit since the core does rcu synchronisation between these steps and we can therefore remove rcu_barrier from l2tp code. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | l2tp: cleanup eth/ppp pseudowire setup codeJames Chapman2024-07-312-4/+6
| | | | | | | | | | | | | | | | | | | | l2tp eth/ppp pseudowire setup/cleanup uses kfree() in some error paths. Drop the refcount instead such that the session object is always freed when the refcount reaches 0. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | l2tp: add idr consistency check in session_registerJames Chapman2024-07-311-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | l2tp_session_register uses an idr_alloc then idr_replace pattern to insert sessions into the session IDR. To catch invalid locking, add a WARN_ON_ONCE if the IDR entry is modified by another thread between alloc and replace steps. Also add comments to make expectations clear. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | l2tp: use rcu list add/del when updating listsJames Chapman2024-07-311-6/+6
| | | | | | | | | | | | | | | | | | | | l2tp_v3_session_htable and tunnel->session_list are read by lockless getters using RCU. Use rcu list variants when adding or removing list items. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | l2tp: prevent possible tunnel refcount underflowJames Chapman2024-07-314-10/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a session is created, it sets a backpointer to its tunnel. When the session refcount drops to 0, l2tp_session_free drops the tunnel refcount if session->tunnel is non-NULL. However, session->tunnel is set in l2tp_session_create, before the tunnel refcount is incremented by l2tp_session_register, which leaves a small window where session->tunnel is non-NULL when the tunnel refcount hasn't been bumped. Moving the assignment to l2tp_session_register is trivial but l2tp_session_create calls l2tp_session_set_header_len which uses session->tunnel to get the tunnel's encap. Add an encap arg to l2tp_session_set_header_len to avoid using session->tunnel. If l2tpv3 sessions have colliding IDs, it is possible for l2tp_v3_session_get to race with l2tp_session_register and fetch a session which doesn't yet have session->tunnel set. Add a check for this case. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | l2tp: refactor ppp socket/session relationshipJames Chapman2024-07-311-55/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Each l2tp ppp session has an associated pppox socket. l2tp_ppp uses the session's pppox socket refcount to manage session lifetimes; the pppox socket holds a ref on the session which is dropped by the socket destructor. This complicates session cleanup. Given l2tp sessions are refcounted, it makes more sense to reverse this relationship such that the session keeps the socket alive, not the other way around. So refactor l2tp_ppp to have the session hold a ref on its socket while it references it. When the session is closed, it drops its socket ref when it detaches from its socket. If the socket is closed first, it initiates the closing of its session, if one is attached. The socket/session can then be freed asynchronously when their refcounts drop to 0. Use the session's session_close callback to detach the pppox socket since this will be done on the work queue together with the rest of the session cleanup via l2tp_session_delete. Also, since l2tp_ppp uses the pppox socket's sk_user_data, use the rcu sk_user_data access helpers when accessing it and set the socket's SOCK_RCU_FREE flag to have pppox sockets freed by rcu. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | l2tp: free sessions using rcuJames Chapman2024-07-312-3/+2
| | | | | | | | | | | | | | | | | | | | l2tp sessions may be accessed under an rcu read lock. Have them freed via rcu and remove the now unneeded synchronize_rcu when a session is removed. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | l2tp: delete sessions using work queueJames Chapman2024-07-312-16/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a tunnel is closed, l2tp_tunnel_closeall closes all sessions in the tunnel. Move the work of deleting each session to the work queue so that sessions are deleted using the same codepath whether they are closed by user API request or their parent tunnel is closing. This also avoids the locking dance in l2tp_tunnel_closeall where the tunnel's session list lock was unlocked and relocked in the loop. In l2tp_exit_net, use drain_workqueue instead of flush_workqueue because the processing of tunnel_delete work may queue session_delete work items which must also be processed. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | l2tp: simplify tunnel and socket cleanupJames Chapman2024-07-312-62/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the l2tp tunnel socket used sk_user_data to point to its associated l2tp tunnel, socket and tunnel cleanup had to make use of the socket's destructor to free the tunnel only when the socket could no longer be accessed. Now that sk_user_data is no longer used, we can simplify socket and tunnel cleanup: * If the tunnel closes first, it cleans up and drops its socket ref when the tunnel refcount drops to zero. If its socket was provided by userspace, the socket is closed and freed asynchronously, when userspace closes it. If its socket is a kernel socket, the tunnel closes the socket itself during cleanup and drops its socket ref when the tunnel's refcount drops to zero. * If the socket closes first, we initiate the closing of its associated tunnel. For UDP sockets, this is via the socket's encap_destroy hook. For L2TPIP sockets, this is via the socket's destroy callback. The tunnel holds a socket ref while it references the sock. When the tunnel is freed, it drops its socket ref and the socket will be cleaned up when its own refcount drops to zero, asynchronous to the tunnel free. * The tunnel socket destructor is no longer needed since the tunnel is no longer freed through the socket destructor. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | l2tp: remove unused tunnel magic fieldJames Chapman2024-07-312-4/+0
| | | | | | | | | | | | | | | | | | | | Since l2tp no longer derives tunnel pointers directly via sk_user_data, it is no longer useful for l2tp to check tunnel pointers using a magic feather. Drop the tunnel's magic field. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | l2tp: don't set sk_user_data in tunnel socketJames Chapman2024-07-311-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | l2tp no longer uses the tunnel socket's sk_user_data so drop the code which sets it. In l2tp_validate_socket use l2tp_sk_to_tunnel to check whether a given socket is already attached to an l2tp tunnel since we can no longer use non-null sk_user_data to indicate this. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | l2tp: don't use tunnel socket sk_user_data in ppp procfs outputJames Chapman2024-07-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | l2tp's ppp procfs output can be used to show internal state of pppol2tp. It includes a 'user-data-ok' field, which is derived from the tunnel socket's sk_user_data being non-NULL. Use tunnel->sock being non-NULL to indicate this instead. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | l2tp: have l2tp_ip_destroy_sock use ip_flush_pending_framesJames Chapman2024-07-311-3/+3
| | | | | | | | | | | | | | | | | | Use the recently exported ip_flush_pending_frames instead of a free-coded version and lock the socket while we call it. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | l2tp: lookup tunnel from socket without using sk_user_dataJames Chapman2024-07-314-17/+54
|/ | | | | | | | | | | | | | | | l2tp_sk_to_tunnel derives the tunnel from sk_user_data. Instead, lookup the tunnel by walking the tunnel IDR for a tunnel using the indicated sock. This is slow but l2tp_sk_to_tunnel is not used in the datapath so performance isn't critical. l2tp_tunnel_destruct needs a variant of l2tp_sk_to_tunnel which does not bump the tunnel refcount since the tunnel refcount is already 0. Change l2tp_sk_to_tunnel sk arg to const since it does not modify sk. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: make session IDR and tunnel session list coherentJames Chapman2024-07-231-18/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Modify l2tp_session_register and l2tp_session_unhash so that the session IDR and tunnel session lists remain coherent. To do so, hold the session IDR lock and the tunnel's session list lock when making any changes to either list. Without this change, a rare race condition could hit the WARN_ON_ONCE in l2tp_session_unhash if a thread replaced the IDR entry while another thread was registering the same ID. [ 7126.151795][T17511] WARNING: CPU: 3 PID: 17511 at net/l2tp/l2tp_core.c:1282 l2tp_session_delete.part.0+0x87e/0xbc0 [ 7126.163754][T17511] ? show_regs+0x93/0xa0 [ 7126.164157][T17511] ? __warn+0xe5/0x3c0 [ 7126.164536][T17511] ? l2tp_session_delete.part.0+0x87e/0xbc0 [ 7126.165070][T17511] ? report_bug+0x2e1/0x500 [ 7126.165486][T17511] ? l2tp_session_delete.part.0+0x87e/0xbc0 [ 7126.166013][T17511] ? handle_bug+0x99/0x130 [ 7126.166428][T17511] ? exc_invalid_op+0x35/0x80 [ 7126.166890][T17511] ? asm_exc_invalid_op+0x1a/0x20 [ 7126.167372][T17511] ? l2tp_session_delete.part.0+0x87d/0xbc0 [ 7126.167900][T17511] ? l2tp_session_delete.part.0+0x87e/0xbc0 [ 7126.168429][T17511] ? __local_bh_enable_ip+0xa4/0x120 [ 7126.168917][T17511] l2tp_session_delete+0x40/0x50 [ 7126.169369][T17511] pppol2tp_release+0x1a1/0x3f0 [ 7126.169817][T17511] __sock_release+0xb3/0x270 [ 7126.170247][T17511] ? __pfx_sock_close+0x10/0x10 [ 7126.170697][T17511] sock_close+0x1c/0x30 [ 7126.171087][T17511] __fput+0x40b/0xb90 [ 7126.171470][T17511] task_work_run+0x16c/0x260 [ 7126.171897][T17511] ? __pfx_task_work_run+0x10/0x10 [ 7126.172362][T17511] ? srso_alias_return_thunk+0x5/0xfbef5 [ 7126.172863][T17511] ? do_raw_spin_unlock+0x174/0x230 [ 7126.173348][T17511] do_exit+0xaae/0x2b40 [ 7126.173730][T17511] ? srso_alias_return_thunk+0x5/0xfbef5 [ 7126.174235][T17511] ? __pfx_lock_release+0x10/0x10 [ 7126.174690][T17511] ? srso_alias_return_thunk+0x5/0xfbef5 [ 7126.175190][T17511] ? do_raw_spin_lock+0x12c/0x2b0 [ 7126.175650][T17511] ? __pfx_do_exit+0x10/0x10 [ 7126.176072][T17511] ? _raw_spin_unlock_irq+0x23/0x50 [ 7126.176543][T17511] do_group_exit+0xd3/0x2a0 [ 7126.176990][T17511] __x64_sys_exit_group+0x3e/0x50 [ 7126.177456][T17511] x64_sys_call+0x1821/0x1830 [ 7126.177895][T17511] do_syscall_64+0xcb/0x250 [ 7126.178317][T17511] entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: aa5e17e1f5ec ("l2tp: store l2tpv3 sessions in per-net IDR") Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20240718134348.289865-1-jchapman@katalix.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
* l2tp: fix l2tp_session_register with colliding l2tpv3 IDsJames Chapman2024-07-121-8/+10
| | | | | | | | | | | | When handling colliding L2TPv3 session IDs, we use the existing session IDR entry and link the new session on that using session->coll_list. However, when using an existing IDR entry, we must not do the idr_replace step. Fixes: aa5e17e1f5ec ("l2tp: store l2tpv3 sessions in per-net IDR") Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: fix possible UAF when cleaning up tunnelsJames Chapman2024-07-091-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot reported a UAF caused by a race when the L2TP work queue closes a tunnel at the same time as a userspace thread closes a session in that tunnel. Tunnel cleanup is handled by a work queue which iterates through the sessions contained within a tunnel, and closes them in turn. Meanwhile, a userspace thread may arbitrarily close a session via either netlink command or by closing the pppox socket in the case of l2tp_ppp. The race condition may occur when l2tp_tunnel_closeall walks the list of sessions in the tunnel and deletes each one. Currently this is implemented using list_for_each_safe, but because the list spinlock is dropped in the loop body it's possible for other threads to manipulate the list during list_for_each_safe's list walk. This can lead to the list iterator being corrupted, leading to list_for_each_safe spinning. One sequence of events which may lead to this is as follows: * A tunnel is created, containing two sessions A and B. * A thread closes the tunnel, triggering tunnel cleanup via the work queue. * l2tp_tunnel_closeall runs in the context of the work queue. It removes session A from the tunnel session list, then drops the list lock. At this point the list_for_each_safe temporary variable is pointing to the other session on the list, which is session B, and the list can be manipulated by other threads since the list lock has been released. * Userspace closes session B, which removes the session from its parent tunnel via l2tp_session_delete. Since l2tp_tunnel_closeall has released the tunnel list lock, l2tp_session_delete is able to call list_del_init on the session B list node. * Back on the work queue, l2tp_tunnel_closeall resumes execution and will now spin forever on the same list entry until the underlying session structure is freed, at which point UAF occurs. The solution is to iterate over the tunnel's session list using list_first_entry_not_null to avoid the possibility of the list iterator pointing at a list item which may be removed during the walk. Also, have l2tp_tunnel_closeall ref each session while it processes it to prevent another thread from freeing it. cpu1 cpu2 --- --- pppol2tp_release() spin_lock_bh(&tunnel->list_lock); for (;;) { session = list_first_entry_or_null(&tunnel->session_list, struct l2tp_session, list); if (!session) break; list_del_init(&session->list); spin_unlock_bh(&tunnel->list_lock); l2tp_session_delete(session); l2tp_session_delete(session); spin_lock_bh(&tunnel->list_lock); } spin_unlock_bh(&tunnel->list_lock); Calling l2tp_session_delete on the same session twice isn't a problem per-se, but if cpu2 manages to destruct the socket and unref the session to zero before cpu1 progresses then it would lead to UAF. Reported-by: syzbot+b471b7c936301a59745b@syzkaller.appspotmail.com Reported-by: syzbot+c041b4ce3a6dfd1e63e2@syzkaller.appspotmail.com Fixes: d18d3f0a24fc ("l2tp: replace hlist with simple list for per-tunnel session list") Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: Tom Parkin <tparkin@katalix.com> Link: https://patch.msgid.link/20240704152508.1923908-1-jchapman@katalix.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
* l2tp: Remove duplicate included header file trace.hThorsten Blum2024-07-041-1/+0
| | | | | | | | | | | | | | | Remove duplicate included header file trace.h and the following warning reported by make includecheck: trace.h is included more than once Compile-tested only. Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> Reviewed-by: Michal Kubiak <michal.kubiak@intel.com> Link: https://patch.msgid.link/20240703061147.691973-2-thorsten.blum@toblux.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
* l2tp: remove incorrect __rcu attributeJames Chapman2024-06-251-1/+1
| | | | | | | | | | | This fixes a sparse warning. Fixes: d18d3f0a24fc ("l2tp: replace hlist with simple list for per-tunnel session list") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202406220754.evK8Hrjw-lkp@intel.com/ Signed-off-by: James Chapman <jchapman@katalix.com> Link: https://patch.msgid.link/20240624082945.1925009-1-jchapman@katalix.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* l2tp: replace hlist with simple list for per-tunnel session listJames Chapman2024-06-213-91/+50
| | | | | | | | | | | | | | | The per-tunnel session list is no longer used by the datapath. However, we still need a list of sessions in the tunnel for l2tp_session_get_nth, which is used by management code. (An alternative might be to walk each session IDR list, matching only sessions of a given tunnel.) Replace the per-tunnel hlist with a per-tunnel list. In functions which walk a list of sessions of a tunnel, walk this list instead. Signed-off-by: James Chapman <jchapman@katalix.com> Reviewed-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: drop the now unused l2tp_tunnel_get_sessionJames Chapman2024-06-212-24/+0
| | | | | | | | | All users of l2tp_tunnel_get_session are now gone so it can be removed. Signed-off-by: James Chapman <jchapman@katalix.com> Reviewed-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: use IDR for all session lookupsJames Chapman2024-06-214-4/+20
| | | | | | | | | | Add generic session getter which uses IDR. Replace all users of l2tp_tunnel_get_session which uses the per-tunnel session list to use the generic getter. Signed-off-by: James Chapman <jchapman@katalix.com> Reviewed-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: don't use sk_user_data in l2tp_udp_encap_err_recvJames Chapman2024-06-211-6/+0
| | | | | | | | | | If UDP sockets are aliased, sk might be the wrong socket. There's no benefit to using sk_user_data to do some checks on the associated tunnel context. Just report the error anyway, like udp core does. Signed-off-by: James Chapman <jchapman@katalix.com> Reviewed-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: refactor udp recv to lookup to not use sk_user_dataJames Chapman2024-06-211-75/+21
| | | | | | | | | | | | | | | | | | | | | | | | | Modify UDP decap to not use the tunnel pointer which comes from the sock's sk_user_data when parsing the L2TP header. By looking up the destination session using only the packet contents we avoid potential UDP 5-tuple aliasing issues which arise from depending on the socket that received the packet. Drop the useless error messages on short packet or on failing to find a session since the tunnel pointer might point to a different tunnel if multiple sockets use the same 5-tuple. Short packets (those not big enough to contain an L2TP header) are no longer counted in the tunnel's invalid counter because we can't derive the tunnel until we parse the l2tp header to lookup the session. l2tp_udp_encap_recv was a small wrapper around l2tp_udp_recv_core which used sk_user_data to derive a tunnel pointer in an RCU-safe way. But we no longer need the tunnel pointer, so remove that code and combine the two functions. Signed-off-by: James Chapman <jchapman@katalix.com> Reviewed-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: store l2tpv2 sessions in per-net IDRJames Chapman2024-06-212-15/+56
| | | | | | | | | | | | | | | | | | | | | L2TPv2 sessions are currently kept in a per-tunnel hashlist, keyed by 16-bit session_id. When handling received L2TPv2 packets, we need to first derive the tunnel using the 16-bit tunnel_id or sock, then lookup the session in a per-tunnel hlist using the 16-bit session_id. We want to avoid using sk_user_data in the datapath and double lookups on every packet. So instead, use a per-net IDR to hold L2TPv2 sessions, keyed by a 32-bit value derived from the 16-bit tunnel_id and session_id. This will allow the L2TPv2 UDP receive datapath to lookup a session with a single lookup without deriving the tunnel first. L2TPv2 sessions are held in their own IDR to avoid potential key collisions with L2TPv3 sessions. Signed-off-by: James Chapman <jchapman@katalix.com> Reviewed-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: store l2tpv3 sessions in per-net IDRJames Chapman2024-06-214-74/+188
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | L2TPv3 sessions are currently held in one of two fixed-size hash lists: either a per-net hashlist (IP-encap), or a per-tunnel hashlist (UDP-encap), keyed by the L2TPv3 32-bit session_id. In order to lookup L2TPv3 sessions in UDP-encap tunnels efficiently without finding the tunnel first via sk_user_data, UDP sessions are now kept in a per-net session list, keyed by session ID. Convert the existing per-net hashlist to use an IDR for better performance when there are many sessions and have L2TPv3 UDP sessions use the same IDR. Although the L2TPv3 RFC states that the session ID alone identifies the session, our implementation has allowed the same session ID to be used in different L2TP UDP tunnels. To retain support for this, a new per-net session hashtable is used, keyed by the sock and session ID. If on creating a new session, a session already exists with that ID in the IDR, the colliding sessions are added to the new hashtable and the existing IDR entry is flagged. When looking up sessions, the approach is to first check the IDR and if no unflagged match is found, check the new hashtable. The sock is made available to session getters where session ID collisions are to be considered. In this way, the new hashtable is used only for session ID collisions so can be kept small. For managing session removal, we need a list of colliding sessions matching a given ID in order to update or remove the IDR entry of the ID. This is necessary to detect session ID collisions when future sessions are created. The list head is allocated on first collision of a given ID and refcounted. Signed-off-by: James Chapman <jchapman@katalix.com> Reviewed-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: remove unused list_head member in l2tp_tunnelJames Chapman2024-06-212-3/+0
| | | | | | | | | Remove an unused variable in struct l2tp_tunnel which was left behind by commit c4d48a58f32c5 ("l2tp: convert l2tp_tunnel_list to idr"). Signed-off-by: James Chapman <jchapman@katalix.com> Reviewed-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* l2tp: fix ICMP error handling for UDP-encap socketsTom Parkin2024-05-171-11/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit a36e185e8c85 ("udp: Handle ICMP errors for tunnels with same destination port on both endpoints") UDP's handling of ICMP errors has allowed for UDP-encap tunnels to determine socket associations in scenarios where the UDP hash lookup could not. Subsequently, commit d26796ae58940 ("udp: check udp sock encap_type in __udp_lib_err") subtly tweaked the approach such that UDP ICMP error handling would be skipped for any UDP socket which has encapsulation enabled. In the case of L2TP tunnel sockets using UDP-encap, this latter modification effectively broke ICMP error reporting for the L2TP control plane. To a degree this isn't catastrophic inasmuch as the L2TP control protocol defines a reliable transport on top of the underlying packet switching network which will eventually detect errors and time out. However, paying attention to the ICMP error reporting allows for more timely detection of errors in L2TP userspace, and aids in debugging connectivity issues. Reinstate ICMP error handling for UDP encap L2TP tunnels: * implement struct udp_tunnel_sock_cfg .encap_err_rcv in order to allow the L2TP code to handle ICMP errors; * only implement error-handling for tunnels which have a managed socket: unmanaged tunnels using a kernel socket have no userspace to report errors back to; * flag the error on the socket, which allows for userspace to get an error such as -ECONNREFUSED back from sendmsg/recvmsg; * pass the error into ip[v6]_icmp_error() which allows for userspace to get extended error information via. MSG_ERRQUEUE. Fixes: d26796ae5894 ("udp: check udp sock encap_type in __udp_lib_err") Signed-off-by: Tom Parkin <tparkin@katalix.com> Link: https://lore.kernel.org/r/20240513172248.623261-1-tparkin@katalix.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* l2tp: Support different protocol versions with same IP/port quadrupleSamuel Thibault2024-05-131-8/+10
| | | | | | | | | | | | | 628bc3e5a1be ("l2tp: Support several sockets with same IP/port quadruple") added support for several L2TPv2 tunnels using the same IP/port quadruple, but if an L2TPv3 socket exists it could eat all the trafic. We thus have to first use the version from the packet to get the proper tunnel, and only then check that the version matches. Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Reviewed-by: James Chapman <jchapman@katalix.com> Link: https://lore.kernel.org/r/20240509205812.4063198-1-samuel.thibault@ens-lyon.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* l2tp: Support several sockets with same IP/port quadrupleSamuel Thibault2024-05-091-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | Some l2tp providers will use 1701 as origin port and open several tunnels for the same origin and target. On the Linux side, this may mean opening several sockets, but then trafic will go to only one of them, losing the trafic for the tunnel of the other socket (or leaving it up to userland, consuming a lot of cpu%). This can also happen when the l2tp provider uses a cluster, and load-balancing happens to migrate from one origin IP to another one, for which a socket was already established. Managing reassigning tunnels from one socket to another would be very hairy for userland. Lastly, as documented in l2tpconfig(1), as client it may be necessary to use 1701 as origin port for odd firewalls reasons, which could prevent from establishing several tunnels to a l2tp server, for the same reason: trafic would get only on one of the two sockets. With the V2 protocol it is however easy to route trafic to the proper tunnel, by looking up the tunnel number in the network namespace. This fixes the three cases altogether. Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Link: https://lore.kernel.org/r/20240506215336.1470009-1-samuel.thibault@ens-lyon.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2024-05-021-0/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Cross-merge networking fixes after downstream PR. Conflicts: include/linux/filter.h kernel/bpf/core.c 66e13b615a0c ("bpf: verifier: prevent userspace memory access") d503a04f8bc0 ("bpf: Add support for certain atomics in bpf_arena to x86 JIT") https://lore.kernel.org/all/20240429114939.210328b0@canb.auug.org.au/ No adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net l2tp: drop flow hash on forwardDavid Bauer2024-04-261-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Drop the flow-hash of the skb when forwarding to the L2TP netdev. This avoids the L2TP qdisc from using the flow-hash from the outer packet, which is identical for every flow within the tunnel. This does not affect every platform but is specific for the ethernet driver. It depends on the platform including L4 information in the flow-hash. One such example is the Mediatek Filogic MT798x family of networking processors. Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support") Acked-by: James Chapman <jchapman@katalix.com> Signed-off-by: David Bauer <mail@david-bauer.net> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://lore.kernel.org/r/20240424171110.13701-1-mail@david-bauer.net Signed-off-by: Paolo Abeni <pabeni@redhat.com>
* | inet: introduce dst_rtable() helperEric Dumazet2024-04-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I added dst_rt6_info() in commit e8dfd42c17fa ("ipv6: introduce dst_rt6_info() helper") This patch does a similar change for IPv4. Instead of (struct rtable *)dst casts, we can use : #define dst_rtable(_ptr) \ container_of_const(_ptr, struct rtable, dst) Patch is smaller than IPv6 one, because IPv4 has skb_rtable() helper. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://lore.kernel.org/r/20240429133009.1227754-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-06 07:17:55 +0000