kernel/linux.git/include/net, branch v6.1.44

tcp: Reduce chance of collisions in inet6_hashfn().

2023-08-03T08:24:00+00:00

[ Upstream commit d11b0df7ddf1831f3e170972f43186dad520bfcc ] For both IPv4 and IPv6 incoming TCP connections are tracked in a hash table with a hash over the source & destination addresses and ports. However, the IPv6 hash is insufficient and can lead to a high rate of collisions. The IPv6 hash used an XOR to fit everything into the 96 bits for the fast jenkins hash, meaning it is possible for an external entity to ensure the hash collides, thus falling back to a linear search in the bucket, which is slow. We take the approach of hash the full length of IPv6 address in __ipv6_addr_jhash() so that all users can benefit from a more secure version. While this may look like it adds overhead, the reality of modern CPUs means that this is unmeasurable in real world scenarios. In simulating with llvm-mca, the increase in cycles for the hashing code was ~16 cycles on Skylake (from a base of ~155), and an extra ~9 on Nehalem (base of ~173). In commit dd6d2910c5e0 ("netfilter: conntrack: switch to siphash") netfilter switched from a jenkins hash to a siphash, but even the faster hsiphash is a more significant overhead (~20-30%) in some preliminary testing. So, in this patch, we keep to the more conservative approach to ensure we don't add much overhead per SYN. In testing, this results in a consistently even spread across the connection buckets. In both testing and real-world scenarios, we have not found any measurable performance impact. Fixes: 08dcdbf6a7b9 ("ipv6: use a stronger hash for tcp") Signed-off-by: Stewart Smith Signed-off-by: Samuel Mendoza-Jonas Suggested-by: Eric Dumazet Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20230721222410.17914-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

vxlan: calculate correct header length for GPE

2023-08-03T08:23:59+00:00

[ Upstream commit 94d166c5318c6edd1e079df8552233443e909c33 ] VXLAN-GPE does not add an extra inner Ethernet header. Take that into account when calculating header length. This causes problems in skb_tunnel_check_pmtu, where incorrect PMTU is cached. In the collect_md mode (which is the only mode that VXLAN-GPE supports), there's no magic auto-setting of the tunnel interface MTU. It can't be, since the destination and thus the underlying interface may be different for each packet. So, the administrator is responsible for setting the correct tunnel interface MTU. Apparently, the administrators are capable enough to calculate that the maximum MTU for VXLAN-GPE is (their_lower_MTU - 36). They set the tunnel interface MTU to 1464. If you run a TCP stream over such interface, it's then segmented according to the MTU 1464, i.e. producing 1514 bytes frames. Which is okay, this still fits the lower MTU. However, skb_tunnel_check_pmtu (called from vxlan_xmit_one) uses 50 as the header size and thus incorrectly calculates the frame size to be 1528. This leads to ICMP too big message being generated (locally), PMTU of 1450 to be cached and the TCP stream to be resegmented. The fix is to use the correct actual header size, especially for skb_tunnel_check_pmtu calculation. Fixes: e1e5314de08ba ("vxlan: implement GPE") Signed-off-by: Jiri Benc Reviewed-by: Simon Horman Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

tcp: annotate data-races around tp->notsent_lowat

2023-07-27T06:50:48+00:00

[ Upstream commit 1aeb87bc1440c5447a7fa2d6e3c2cca52cbd206b ] tp->notsent_lowat can be read locklessly from do_tcp_getsockopt() and tcp_poll(). Fixes: c9bee3b7fdec ("tcp: TCP_NOTSENT_LOWAT socket option") Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20230719212857.3943972-10-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

tcp: annotate data-races around tp->keepalive_probes

2023-07-27T06:50:48+00:00

[ Upstream commit 6e5e1de616bf5f3df1769abc9292191dfad9110a ] do_tcp_getsockopt() reads tp->keepalive_probes while another cpu might change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20230719212857.3943972-6-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

tcp: annotate data-races around tp->keepalive_intvl

2023-07-27T06:50:48+00:00

[ Upstream commit 5ecf9d4f52ff2f1d4d44c9b68bc75688e82f13b4 ] do_tcp_getsockopt() reads tp->keepalive_intvl while another cpu might change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20230719212857.3943972-5-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

tcp: annotate data-races around tp->keepalive_time

2023-07-27T06:50:48+00:00

[ Upstream commit 4164245c76ff906c9086758e1c3f87082a7f5ef5 ] do_tcp_getsockopt() reads tp->keepalive_time while another cpu might change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20230719212857.3943972-4-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

Bluetooth: use RCU for hci_conn_params and iterate safely in hci_sync

2023-07-27T06:50:47+00:00

[ Upstream commit 195ef75e19287b4bc413da3e3e3722b030ac881e ] hci_update_accept_list_sync iterates over hdev->pend_le_conns and hdev->pend_le_reports, and waits for controller events in the loop body, without holding hdev lock. Meanwhile, these lists and the items may be modified e.g. by le_scan_cleanup. This can invalidate the list cursor or any other item in the list, resulting to invalid behavior (eg use-after-free). Use RCU for the hci_conn_params action lists. Since the loop bodies in hci_sync block and we cannot use RCU or hdev->lock for the whole loop, copy list items first and then iterate on the copy. Only the flags field is written from elsewhere, so READ_ONCE/WRITE_ONCE should guarantee we read valid values. Free params everywhere with hci_conn_params_free so the cleanup is guaranteed to be done properly. This fixes the following, which can be triggered e.g. by BlueZ new mgmt-tester case "Add + Remove Device Nowait - Success", or by changing hci_le_set_cig_params to always return false, and running iso-tester: ================================================================== BUG: KASAN: slab-use-after-free in hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841) Read of size 8 at addr ffff888001265018 by task kworker/u3:0/32 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014 Workqueue: hci0 hci_cmd_sync_work Call Trace: dump_stack_lvl (./arch/x86/include/asm/irqflags.h:134 lib/dump_stack.c:107) print_report (mm/kasan/report.c:320 mm/kasan/report.c:430) ? __virt_addr_valid (./include/linux/mmzone.h:1915 ./include/linux/mmzone.h:2011 arch/x86/mm/physaddr.c:65) ? hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841) kasan_report (mm/kasan/report.c:538) ? hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841) hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2536 net/bluetooth/hci_sync.c:2723 net/bluetooth/hci_sync.c:2841) ? __pfx_hci_update_passive_scan_sync (net/bluetooth/hci_sync.c:2780) ? mutex_lock (kernel/locking/mutex.c:282) ? __pfx_mutex_lock (kernel/locking/mutex.c:282) ? __pfx_mutex_unlock (kernel/locking/mutex.c:538) ? __pfx_update_passive_scan_sync (net/bluetooth/hci_sync.c:2861) hci_cmd_sync_work (net/bluetooth/hci_sync.c:306) process_one_work (./arch/x86/include/asm/preempt.h:27 kernel/workqueue.c:2399) worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2538) ? __pfx_worker_thread (kernel/workqueue.c:2480) kthread (kernel/kthread.c:376) ? __pfx_kthread (kernel/kthread.c:331) ret_from_fork (arch/x86/entry/entry_64.S:314) Allocated by task 31: kasan_save_stack (mm/kasan/common.c:46) kasan_set_track (mm/kasan/common.c:52) __kasan_kmalloc (mm/kasan/common.c:374 mm/kasan/common.c:383) hci_conn_params_add (./include/linux/slab.h:580 ./include/linux/slab.h:720 net/bluetooth/hci_core.c:2277) hci_connect_le_scan (net/bluetooth/hci_conn.c:1419 net/bluetooth/hci_conn.c:1589) hci_connect_cis (net/bluetooth/hci_conn.c:2266) iso_connect_cis (net/bluetooth/iso.c:390) iso_sock_connect (net/bluetooth/iso.c:899) __sys_connect (net/socket.c:2003 net/socket.c:2020) __x64_sys_connect (net/socket.c:2027) do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) Freed by task 15: kasan_save_stack (mm/kasan/common.c:46) kasan_set_track (mm/kasan/common.c:52) kasan_save_free_info (mm/kasan/generic.c:523) __kasan_slab_free (mm/kasan/common.c:238 mm/kasan/common.c:200 mm/kasan/common.c:244) __kmem_cache_free (mm/slub.c:1807 mm/slub.c:3787 mm/slub.c:3800) hci_conn_params_del (net/bluetooth/hci_core.c:2323) le_scan_cleanup (net/bluetooth/hci_conn.c:202) process_one_work (./arch/x86/include/asm/preempt.h:27 kernel/workqueue.c:2399) worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2538) kthread (kernel/kthread.c:376) ret_from_fork (arch/x86/entry/entry_64.S:314) ================================================================== Fixes: e8907f76544f ("Bluetooth: hci_sync: Make use of hci_cmd_sync_queue set 3") Signed-off-by: Pauli Virtanen Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

net: ipv4: use consistent txhash in TIME_WAIT and SYN_RECV

2023-07-27T06:50:44+00:00

[ Upstream commit c0a8966e2bc7d31f77a7246947ebc09c1ff06066 ] When using IPv4/TCP, skb->hash comes from sk->sk_txhash except in TIME_WAIT and SYN_RECV where it's not set in the reply skb from ip_send_unicast_reply. Those packets will have a mismatched hash with others from the same flow as their hashes will be 0. IPv6 does not have the same issue as the hash is set from the socket txhash in those cases. This commits sets the hash in the reply skb from ip_send_unicast_reply, which makes the IPv4 code behaving like IPv6. Signed-off-by: Antoine Tenart Reviewed-by: Eric Dumazet Signed-off-by: Paolo Abeni Stable-dep-of: 5e5265522a9a ("tcp: annotate data-races around tcp_rsk(req)->txhash") Signed-off-by: Sasha Levin

net/sched: make psched_mtu() RTNL-less safe

2023-07-23T11:49:27+00:00

[ Upstream commit 150e33e62c1fa4af5aaab02776b6c3812711d478 ] Eric Dumazet says[1]: ------- Speaking of psched_mtu(), I see that net/sched/sch_pie.c is using it without holding RTNL, so dev->mtu can be changed underneath. KCSAN could issue a warning. ------- Annotate dev->mtu with READ_ONCE() so KCSAN don't issue a warning. [1] https://lore.kernel.org/all/CANn89iJoJO5VtaJ-2=_d2aOQhb0Xw8iBT_Cxqp2HyuS-zj6azw@mail.gmail.com/ v1 -> v2: Fix commit message Fixes: d4b36210c2e6 ("net: pkt_sched: PIE AQM scheme") Suggested-by: Eric Dumazet Signed-off-by: Pedro Tammela Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230711021634.561598-1-pctammela@mojatatu.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

Bluetooth: MGMT: Fix marking SCAN_RSP as not connectable

2023-07-19T14:22:02+00:00

[ Upstream commit 73f55453ea5236a586a7f1b3d5e2ee051d655351 ] When receiving a scan response there is no way to know if the remote device is connectable or not, so when it cannot be merged don't make any assumption and instead just mark it with a new flag defined as MGMT_DEV_FOUND_SCAN_RSP so userspace can tell it is a standalone SCAN_RSP. Link: https://lore.kernel.org/linux-bluetooth/CABBYNZ+CYMsDSPTxBn09Js3BcdC-x7vZFfyLJ3ppZGGwJKmUTw@mail.gmail.com/ Fixes: c70a7e4cc8d2 ("Bluetooth: Add support for Not Connectable flag for Device Found events") Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin