kernel/linux.git/include/net/udp.h, branch v5.10.257

net: drop UFO packets in udp_rcv_segment()

2025-08-28T14:22:37+00:00

[ Upstream commit d46e51f1c78b9ab9323610feb14238d06d46d519 ] When sending a packet with virtio_net_hdr to tun device, if the gso_type in virtio_net_hdr is SKB_GSO_UDP and the gso_size is less than udphdr size, below crash may happen. ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:4572! Oops: invalid opcode: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 62 Comm: mytest Not tainted 6.16.0-rc7 #203 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:skb_pull_rcsum+0x8e/0xa0 Code: 00 00 5b c3 cc cc cc cc 8b 93 88 00 00 00 f7 da e8 37 44 38 00 f7 d8 89 83 88 00 00 00 48 8b 83 c8 00 00 00 5b c3 cc cc cc cc <0f> 0b 0f 0b 66 66 2e 0f 1f 84 00 000 RSP: 0018:ffffc900001fba38 EFLAGS: 00000297 RAX: 0000000000000004 RBX: ffff8880040c1000 RCX: ffffc900001fb948 RDX: ffff888003e6d700 RSI: 0000000000000008 RDI: ffff88800411a062 RBP: ffff8880040c1000 R08: 0000000000000000 R09: 0000000000000001 R10: ffff888003606c00 R11: 0000000000000001 R12: 0000000000000000 R13: ffff888004060900 R14: ffff888004050000 R15: ffff888004060900 FS: 000000002406d3c0(0000) GS:ffff888084a19000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000040 CR3: 0000000004007000 CR4: 00000000000006f0 Call Trace: udp_queue_rcv_one_skb+0x176/0x4b0 net/ipv4/udp.c:2445 udp_queue_rcv_skb+0x155/0x1f0 net/ipv4/udp.c:2475 udp_unicast_rcv_skb+0x71/0x90 net/ipv4/udp.c:2626 __udp4_lib_rcv+0x433/0xb00 net/ipv4/udp.c:2690 ip_protocol_deliver_rcu+0xa6/0x160 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x72/0x90 net/ipv4/ip_input.c:233 ip_sublist_rcv_finish+0x5f/0x70 net/ipv4/ip_input.c:579 ip_sublist_rcv+0x122/0x1b0 net/ipv4/ip_input.c:636 ip_list_rcv+0xf7/0x130 net/ipv4/ip_input.c:670 __netif_receive_skb_list_core+0x21d/0x240 net/core/dev.c:6067 netif_receive_skb_list_internal+0x186/0x2b0 net/core/dev.c:6210 napi_complete_done+0x78/0x180 net/core/dev.c:6580 tun_get_user+0xa63/0x1120 drivers/net/tun.c:1909 tun_chr_write_iter+0x65/0xb0 drivers/net/tun.c:1984 vfs_write+0x300/0x420 fs/read_write.c:593 ksys_write+0x60/0xd0 fs/read_write.c:686 do_syscall_64+0x50/0x1c0 arch/x86/entry/syscall_64.c:63 To trigger gso segment in udp_queue_rcv_skb(), we should also set option UDP_ENCAP_ESPINUDP to enable udp_sk(sk)->encap_rcv. When the encap_rcv hook return 1 in udp_queue_rcv_one_skb(), udp_csum_pull_header() will try to pull udphdr, but the skb size has been segmented to gso size, which leads to this crash. Previous commit cf329aa42b66 ("udp: cope with UDP GRO packet misdirection") introduces segmentation in UDP receive path only for GRO, which was never intended to be used for UFO, so drop UFO packets in udp_rcv_segment(). Link: https://lore.kernel.org/netdev/20250724083005.3918375-1-wangliang74@huawei.com/ Link: https://lore.kernel.org/netdev/20250729123907.3318425-1-wangliang74@huawei.com/ Fixes: cf329aa42b66 ("udp: cope with UDP GRO packet misdirection") Suggested-by: Willem de Bruijn Signed-off-by: Wang Liang Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250730101458.3470788-1-wangliang74@huawei.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

bpf: Clean up sockmap related Kconfigs

2025-06-27T10:04:09+00:00

[ Upstream commit 887596095ec2a9ea39ffcf98f27bf2e77c5eb512 ] As suggested by John, clean up sockmap related Kconfigs: Reduce the scope of CONFIG_BPF_STREAM_PARSER down to TCP stream parser, to reflect its name. Make the rest sockmap code simply depend on CONFIG_BPF_SYSCALL and CONFIG_INET, the latter is still needed at this point because of TCP/UDP proto update. And leave CONFIG_NET_SOCK_MSG untouched, as it is used by non-sockmap cases. Signed-off-by: Cong Wang Signed-off-by: Alexei Starovoitov Reviewed-by: Lorenz Bauer Acked-by: John Fastabend Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/20210223184934.6054-2-xiyou.wangcong@gmail.com Stable-dep-of: 2660a544fdc0 ("net: Fix TOCTOU issue in sk_is_readable()") Signed-off-by: Sasha Levin

tcp/udp: Call inet6_destroy_sock() in IPv6 sk->sk_destruct().

2023-04-26T09:27:41+00:00

commit d38afeec26ed4739c640bf286c270559aab2ba5f upstream. Originally, inet6_sk(sk)->XXX were changed under lock_sock(), so we were able to clean them up by calling inet6_destroy_sock() during the IPv6 -> IPv4 conversion by IPV6_ADDRFORM. However, commit 03485f2adcde ("udpv6: Add lockless sendmsg() support") added a lockless memory allocation path, which could cause a memory leak: setsockopt(IPV6_ADDRFORM) sendmsg() +-----------------------+ +-------+ - do_ipv6_setsockopt(sk, ...) - udpv6_sendmsg(sk, ...) - sockopt_lock_sock(sk) ^._ called via udpv6_prot - lock_sock(sk) before WRITE_ONCE() - WRITE_ONCE(sk->sk_prot, &tcp_prot) - inet6_destroy_sock() - if (!corkreq) - sockopt_release_sock(sk) - ip6_make_skb(sk, ...) - release_sock(sk) ^._ lockless fast path for the non-corking case - __ip6_append_data(sk, ...) - ipv6_local_rxpmtu(sk, ...) - xchg(&np->rxpmtu, skb) ^._ rxpmtu is never freed. - goto out_no_dst; - lock_sock(sk) For now, rxpmtu is only the case, but not to miss the future change and a similar bug fixed in commit e27326009a3d ("net: ping6: Fix memleak in ipv6_renew_options()."), let's set a new function to IPv6 sk->sk_destruct() and call inet6_cleanup_sock() there. Since the conversion does not change sk->sk_destruct(), we can guarantee that we can clean up IPv6 resources finally. We can now remove all inet6_destroy_sock() calls from IPv6 protocol specific ->destroy() functions, but such changes are invasive to backport. So they can be posted as a follow-up later for net-next. Fixes: 03485f2adcde ("udpv6: Add lockless sendmsg() support") Signed-off-by: Kuniyuki Iwashima Signed-off-by: Jakub Kicinski Signed-off-by: Ziyang Xuan Signed-off-by: Greg Kroah-Hartman

tcp/udp: Make early_demux back namespacified.

2022-11-10T17:14:26+00:00

commit 11052589cf5c0bab3b4884d423d5f60c38fcf25d upstream. Commit e21145a9871a ("ipv4: namespacify ip_early_demux sysctl knob") made it possible to enable/disable early_demux on a per-netns basis. Then, we introduced two knobs, tcp_early_demux and udp_early_demux, to switch it for TCP/UDP in commit dddb64bcb346 ("net: Add sysctl to toggle early demux for tcp and udp"). However, the .proc_handler() was wrong and actually disabled us from changing the behaviour in each netns. We can execute early_demux if net.ipv4.ip_early_demux is on and each proto .early_demux() handler is not NULL. When we toggle (tcp|udp)_early_demux, the change itself is saved in each netns variable, but the .early_demux() handler is a global variable, so the handler is switched based on the init_net's sysctl variable. Thus, netns (tcp|udp)_early_demux knobs have nothing to do with the logic. Whether we CAN execute proto .early_demux() is always decided by init_net's sysctl knob, and whether we DO it or not is by each netns ip_early_demux knob. This patch namespacifies (tcp|udp)_early_demux again. For now, the users of the .early_demux() handler are TCP and UDP only, and they are called directly to avoid retpoline. So, we can remove the .early_demux() handler from inet6?_protos and need not dereference them in ip6?_rcv_finish_core(). If another proto needs .early_demux(), we can restore it at that time. Fixes: dddb64bcb346 ("net: Add sysctl to toggle early demux for tcp and udp") Signed-off-by: Kuniyuki Iwashima Link: https://lore.kernel.org/r/20220713175207.7727-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

udp: Fix a data-race around sysctl_udp_l3mdev_accept.

2022-07-29T15:19:21+00:00

[ Upstream commit 3d72bb4188c708bb16758c60822fc4dda7a95174 ] While reading sysctl_udp_l3mdev_accept, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 63a6fff353d0 ("net: Avoid receiving packets with an l3mdev on unbound UDP sockets") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

udp: call udp_encap_enable for v6 sockets when enabling encap

2022-04-08T12:39:54+00:00

commit a4a600dd301ccde6ea239804ec1f19364a39d643 upstream. When enabling encap for a ipv6 socket without udp_encap_needed_key increased, UDP GRO won't work for v4 mapped v6 address packets as sk will be NULL in udp4_gro_receive(). This patch is to enable it by increasing udp_encap_needed_key for v6 sockets in udp_tunnel_encap_enable(), and correspondingly decrease udp_encap_needed_key in udpv6_destroy_sock(). v1->v2: - add udp_encap_disable() and export it. v2->v3: - add the change for rxrpc and bareudp into one patch, as Alex suggested. v3->v4: - move rxrpc part to another patch. Acked-by: Willem de Bruijn Signed-off-by: Xin Long Signed-off-by: Jakub Kicinski Tested-by: Antonio Quartulli Signed-off-by: Greg Kroah-Hartman

net: multicast: calculate csum of looped-back and forwarded packets

2021-11-18T13:03:43+00:00

[ Upstream commit 9122a70a6333705c0c35614ddc51c274ed1d3637 ] During a testing of an user-space application which transmits UDP multicast datagrams and utilizes multicast routing to send the UDP datagrams out of defined network interfaces, I've found a multicast router does not fill-in UDP checksum into locally produced, looped-back and forwarded UDP datagrams, if an original output NIC the datagrams are sent to has UDP TX checksum offload enabled. The datagrams are sent malformed out of the NIC the datagrams have been forwarded to. It is because: 1. If TX checksum offload is enabled on the output NIC, UDP checksum is not calculated by kernel and is not filled into skb data. 2. dev_loopback_xmit(), which is called solely by ip_mc_finish_output(), sets skb->ip_summed = CHECKSUM_UNNECESSARY unconditionally. 3. Since 35fc92a9 ("[NET]: Allow forwarding of ip_summed except CHECKSUM_COMPLETE"), the ip_summed value is preserved during forwarding. 4. If ip_summed != CHECKSUM_PARTIAL, checksum is not calculated during a packet egress. The minimum fix in dev_loopback_xmit(): 1. Preserves skb->ip_summed CHECKSUM_PARTIAL. This is the case when the original output NIC has TX checksum offload enabled. The effects are: a) If the forwarding destination interface supports TX checksum offloading, the NIC driver is responsible to fill-in the checksum. b) If the forwarding destination interface does NOT support TX checksum offloading, checksums are filled-in by kernel before skb is submitted to the NIC driver. c) For local delivery, checksum validation is skipped as in the case of CHECKSUM_UNNECESSARY, thanks to skb_csum_unnecessary(). 2. Translates ip_summed CHECKSUM_NONE to CHECKSUM_UNNECESSARY. It means, for CHECKSUM_NONE, the behavior is unmodified and is there to skip a looped-back packet local delivery checksum validation. Signed-off-by: Cyril Strejc Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

udp: ipv4: manipulate network header of NATed UDP GRO fraglist

2021-02-10T08:29:23+00:00

commit c3df39ac9b0e3747bf8233ea9ce4ed5ceb3199d3 upstream. UDP/IP header of UDP GROed frag_skbs are not updated even after NAT forwarding. Only the header of head_skb from ip_finish_output_gso -> skb_gso_segment is updated but following frag_skbs are not updated. A call path skb_mac_gso_segment -> inet_gso_segment -> udp4_ufo_fragment -> __udp_gso_segment -> __udp_gso_segment_list does not try to update UDP/IP header of the segment list but copy only the MAC header. Update port, addr and check of each skb of the segment list in __udp_gso_segment_list. It covers both SNAT and DNAT. Fixes: 9fd1ff5d2ac7 (udp: Support UDP fraglist GRO/GSO.) Signed-off-by: Dongseok Yi Acked-by: Steffen Klassert Link: https://lore.kernel.org/r/1611962007-80092-1-git-send-email-dseok.yi@samsung.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net/udp: switch udp_lib_setsockopt to sockptr_t

2020-07-24T22:41:54+00:00

Pass a sockptr_t to prepare for set_fs-less handling of the kernel pointer from bpf-cgroup. Signed-off-by: Christoph Hellwig Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2020-07-05T00:48:34+00:00

Daniel Borkmann says: ==================== pull-request: bpf-next 2020-07-04 The following pull-request contains BPF updates for your *net-next* tree. We've added 73 non-merge commits during the last 17 day(s) which contain a total of 106 files changed, 5233 insertions(+), 1283 deletions(-). The main changes are: 1) bpftool ability to show PIDs of processes having open file descriptors for BPF map/program/link/BTF objects, relying on BPF iterator progs to extract this info efficiently, from Andrii Nakryiko. 2) Addition of BPF iterator progs for dumping TCP and UDP sockets to seq_files, from Yonghong Song. 3) Support access to BPF map fields in struct bpf_map from programs through BTF struct access, from Andrey Ignatov. 4) Add a bpf_get_task_stack() helper to be able to dump /proc/*/stack via seq_file from BPF iterator progs, from Song Liu. 5) Make SO_KEEPALIVE and related options available to bpf_setsockopt() helper, from Dmitry Yakunin. 6) Optimize BPF sk_storage selection of its caching index, from Martin KaFai Lau. 7) Removal of redundant synchronize_rcu()s from BPF map destruction which has been a historic leftover, from Alexei Starovoitov. 8) Several improvements to test_progs to make it easier to create a shell loop that invokes each test individually which is useful for some CIs, from Jesper Dangaard Brouer. 9) Fix bpftool prog dump segfault when compiled without skeleton code on older clang versions, from John Fastabend. 10) Bunch of cleanups and minor improvements, from various others. ==================== Signed-off-by: David S. Miller