kernel/linux.git/net/sctp/ipv6.c, branch linux-7.1.y

sctp: disable BH before calling udp_tunnel_xmit_skb()

2026-04-13T23:50:28+00:00

udp_tunnel_xmit_skb() / udp_tunnel6_xmit_skb() are expected to run with BH disabled. After commit 6f1a9140ecda ("add xmit recursion limit to tunnel xmit functions"), on the path: udp(6)_tunnel_xmit_skb() -> ip(6)tunnel_xmit() dev_xmit_recursion_inc()/dec() must stay balanced on the same CPU. Without local_bh_disable(), the context may move between CPUs, which can break the inc/dec pairing. This may lead to incorrect recursion level detection and cause packets to be dropped in ip(6)_tunnel_xmit() or __dev_queue_xmit(). Fix it by disabling BH around both IPv4 and IPv6 SCTP UDP xmit paths. In my testing, after enabling the SCTP over UDP: # ip net exec ha sysctl -w net.sctp.udp_port=9899 # ip net exec ha sysctl -w net.sctp.encap_port=9899 # ip net exec hb sysctl -w net.sctp.udp_port=9899 # ip net exec hb sysctl -w net.sctp.encap_port=9899 # ip net exec ha iperf3 -s - without this patch: # ip net exec hb iperf3 -c 192.168.0.1 --sctp [ 5] 0.00-10.00 sec 37.2 MBytes 31.2 Mbits/sec sender [ 5] 0.00-10.00 sec 37.1 MBytes 31.1 Mbits/sec receiver - with this patch: # ip net exec hb iperf3 -c 192.168.0.1 --sctp [ 5] 0.00-10.00 sec 3.14 GBytes 2.69 Gbits/sec sender [ 5] 0.00-10.00 sec 3.14 GBytes 2.69 Gbits/sec receiver Fixes: 6f1a9140ecda ("net: add xmit recursion limit to tunnel xmit functions") Fixes: 046c052b475e ("sctp: enable udp tunneling socks") Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Link: https://patch.msgid.link/c874a8548221dcd56ff03c65ba75a74e6cf99119.1776017727.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

sctp: Clear inet_opt in sctp_v6_copy_ip_options().

2025-12-18T15:18:00+00:00

syzbot reported the splat below. [0] Since the cited commit, the child socket inherits all fields of its parent socket unless explicitly cleared. syzbot set IP_OPTIONS to AF_INET6 socket and created a child socket inheriting inet_sk(sk)->inet_opt. sctp_v6_copy_ip_options() only clones np->opt, and leaving inet_opt results in double-free. Let's clear inet_opt in sctp_v6_copy_ip_options(). [0]: BUG: KASAN: double-free in inet_sock_destruct+0x538/0x740 net/ipv4/af_inet.c:159 Free of addr ffff8880304b6d40 by task ksoftirqd/0/15 CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report_invalid_free+0xea/0x110 mm/kasan/report.c:557 check_slab_allocation+0xe1/0x130 include/linux/page-flags.h:-1 kasan_slab_pre_free include/linux/kasan.h:198 [inline] slab_free_hook mm/slub.c:2484 [inline] slab_free mm/slub.c:6630 [inline] kfree+0x148/0x6d0 mm/slub.c:6837 inet_sock_destruct+0x538/0x740 net/ipv4/af_inet.c:159 __sk_destruct+0x89/0x660 net/core/sock.c:2350 sock_put include/net/sock.h:1991 [inline] sctp_endpoint_destroy_rcu+0xa1/0xf0 net/sctp/endpointola.c:197 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xcab/0x1770 kernel/rcu/tree.c:2861 handle_softirqs+0x286/0x870 kernel/softirq.c:622 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 6003: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5642 [inline] __kmalloc_noprof+0x411/0x7f0 mm/slub.c:5654 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] ip_options_get+0x51/0x4c0 net/ipv4/ip_options.c:517 do_ip_setsockopt+0x1d9b/0x2d00 net/ipv4/ip_sockglue.c:1087 ip_setsockopt+0x66/0x110 net/ipv4/ip_sockglue.c:1417 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2360 __sys_setsockopt net/socket.c:2385 [inline] __do_sys_setsockopt net/socket.c:2391 [inline] __se_sys_setsockopt net/socket.c:2388 [inline] __x64_sys_setsockopt+0x13f/0x1b0 net/socket.c:2388 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2539 [inline] slab_free mm/slub.c:6630 [inline] kfree+0x19a/0x6d0 mm/slub.c:6837 inet_sock_destruct+0x538/0x740 net/ipv4/af_inet.c:159 __sk_destruct+0x89/0x660 net/core/sock.c:2350 sock_put include/net/sock.h:1991 [inline] sctp_endpoint_destroy_rcu+0xa1/0xf0 net/sctp/endpointola.c:197 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xcab/0x1770 kernel/rcu/tree.c:2861 handle_softirqs+0x286/0x870 kernel/softirq.c:622 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Fixes: 16942cf4d3e31 ("sctp: Use sk_clone() in sctp_accept().") Reported-by: syzbot+ec33a1a006ed5abe7309@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6936d112.a70a0220.38f243.00a8.GAE@google.com/ Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20251210081206.1141086-3-kuniyu@google.com Acked-by: Xin Long Signed-off-by: Paolo Abeni

sctp: Remove sctp_pf.create_accept_sk().

2025-10-28T01:04:58+00:00

sctp_v[46]_create_accept_sk() are no longer used. Let's remove sctp_pf.create_accept_sk(). Signed-off-by: Kuniyuki Iwashima Acked-by: Xin Long Link: https://patch.msgid.link/20251023231751.4168390-7-kuniyu@google.com Signed-off-by: Jakub Kicinski

sctp: Don't call sk->sk_prot->init() in sctp_v[46]_create_accept_sk().

2025-10-28T01:04:57+00:00

sctp_accept() calls sctp_v[46]_create_accept_sk() to allocate a new socket and calls sctp_sock_migrate() to copy fields from the parent socket to the new socket. sctp_v[46]_create_accept_sk() calls sctp_init_sock() to initialise sctp_sock, but most fields are overwritten by sctp_copy_descendant() called from sctp_sock_migrate(). Things done in sctp_init_sock() but not in sctp_sock_migrate() are the following: 1. Copy sk->sk_gso 2. Copy sk->sk_destruct (sctp_v6_init_sock()) 3. Allocate sctp_sock.ep 4. Initialise sctp_sock.pd_lobby 5. Count sk_sockets_allocated_inc(), sock_prot_inuse_add(), and SCTP_DBG_OBJCNT_INC() Let's do these in sctp_copy_sock() and sctp_sock_migrate() and avoid calling sk->sk_prot->init() in sctp_v[46]_create_accept_sk(). Note that sk->sk_destruct is already copied in sctp_copy_sock(). Signed-off-by: Kuniyuki Iwashima Acked-by: Xin Long Link: https://patch.msgid.link/20251023231751.4168390-4-kuniyu@google.com Signed-off-by: Jakub Kicinski

ipv6: Move ipv6_fl_list from ipv6_pinfo to inet_sock.

2025-10-17T23:06:52+00:00

In {tcp6,udp6,raw6}_sock, struct ipv6_pinfo is always placed at the beginning of a new cache line because 1. __alignof__(struct tcp_sock) is 64 due to ____cacheline_aligned of __cacheline_group_begin(tcp_sock_write_tx) 2. __alignof__(struct udp_sock) is 64 due to ____cacheline_aligned of struct numa_drop_counters 3. in raw6_sock, struct numa_drop_counters is placed before struct ipv6_pinfo . struct ipv6_pinfo is 136 bytes, but the last cache line is only used by ipv6_fl_list: $ pahole -C ipv6_pinfo vmlinux struct ipv6_pinfo { ... /* --- cacheline 2 boundary (128 bytes) --- */ struct ipv6_fl_socklist * ipv6_fl_list; /* 128 8 */ /* size: 136, cachelines: 3, members: 23 */ Let's move ipv6_fl_list from struct ipv6_pinfo to struct inet_sock to save a full cache line for {tcp6,udp6,raw6}_sock. Now, struct ipv6_pinfo is 128 bytes, and {tcp6,udp6,raw6}_sock have 64 bytes less, while {tcp,udp,raw}_sock retain the same size. Before: # grep -E "^(RAW|UDP[^L\-]|TCP)" /proc/slabinfo | awk '{print $1, "\t", $4}' RAWv6 1408 UDPv6 1472 TCPv6 2560 RAW 1152 UDP 1280 TCP 2368 After: # grep -E "^(RAW|UDP[^L\-]|TCP)" /proc/slabinfo | awk '{print $1, "\t", $4}' RAWv6 1344 UDPv6 1408 TCPv6 2496 RAW 1152 UDP 1280 TCP 2368 Also, ipv6_fl_list and inet_flags (SNDFLOW bit) are placed in the same cache line. $ pahole -C inet_sock vmlinux ... /* --- cacheline 11 boundary (704 bytes) was 56 bytes ago --- */ struct ipv6_pinfo * pinet6; /* 760 8 */ /* --- cacheline 12 boundary (768 bytes) --- */ struct ipv6_fl_socklist * ipv6_fl_list; /* 768 8 */ unsigned long inet_flags; /* 776 8 */ Doc churn is due to the insufficient Type column (only 1 space short). Suggested-by: Eric Dumazet Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20251014224210.2964778-1-kuniyu@google.com Signed-off-by: Jakub Kicinski

sctp: initialize more fields in sctp_v6_from_sk()

2025-08-28T00:15:21+00:00

syzbot found that sin6_scope_id was not properly initialized, leading to undefined behavior. Clear sin6_scope_id and sin6_flowinfo. BUG: KMSAN: uninit-value in __sctp_v6_cmp_addr+0x887/0x8c0 net/sctp/ipv6.c:649 __sctp_v6_cmp_addr+0x887/0x8c0 net/sctp/ipv6.c:649 sctp_inet6_cmp_addr+0x4f2/0x510 net/sctp/ipv6.c:983 sctp_bind_addr_conflict+0x22a/0x3b0 net/sctp/bind_addr.c:390 sctp_get_port_local+0x21eb/0x2440 net/sctp/socket.c:8452 sctp_get_port net/sctp/socket.c:8523 [inline] sctp_listen_start net/sctp/socket.c:8567 [inline] sctp_inet_listen+0x710/0xfd0 net/sctp/socket.c:8636 __sys_listen_socket net/socket.c:1912 [inline] __sys_listen net/socket.c:1927 [inline] __do_sys_listen net/socket.c:1932 [inline] __se_sys_listen net/socket.c:1930 [inline] __x64_sys_listen+0x343/0x4c0 net/socket.c:1930 x64_sys_call+0x271d/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:51 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Local variable addr.i.i created at: sctp_get_port net/sctp/socket.c:8515 [inline] sctp_listen_start net/sctp/socket.c:8567 [inline] sctp_inet_listen+0x650/0xfd0 net/sctp/socket.c:8636 __sys_listen_socket net/socket.c:1912 [inline] __sys_listen net/socket.c:1927 [inline] __do_sys_listen net/socket.c:1932 [inline] __se_sys_listen net/socket.c:1930 [inline] __x64_sys_listen+0x343/0x4c0 net/socket.c:1930 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+e69f06a0f30116c68056@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/68adc0a2.050a0220.37038e.00c4.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Cc: Marcelo Ricardo Leitner Acked-by: Xin Long Link: https://patch.msgid.link/20250826141314.1802610-1-edumazet@google.com Signed-off-by: Jakub Kicinski

net: ipv6: Add a flags argument to ip6tunnel_xmit(), udp_tunnel6_xmit_skb()

2025-06-18T01:18:45+00:00

ip6tunnel_xmit() erases the contents of the SKB control block. In order to be able to set particular IP6CB flags on the SKB, add a corresponding parameter, and propagate it to udp_tunnel6_xmit_skb() as well. In one of the following patches, VXLAN driver will use this facility to mark packets as subject to IPv6 multicast routing. Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Reviewed-by: Nikolay Aleksandrov Link: https://patch.msgid.link/acb4f9f3e40c3a931236c3af08a720b017fbfbfb.1750113335.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski

net: ipv6: Make udp_tunnel6_xmit_skb() void

2025-06-18T01:18:45+00:00

The function always returns zero, thus the return value does not carry any signal. Just make it void. Most callers already ignore the return value. However: - Refold arguments of the call from sctp_v6_xmit() so that they fit into the 80-column limit. - tipc_udp_xmit() initializes err from the return value, but that should already be always zero at that point. So there's no practical change, but elision of the assignment prompts a couple more tweaks to clean up the function. Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Reviewed-by: Nikolay Aleksandrov Link: https://patch.msgid.link/7facacf9d8ca3ca9391a4aee88160913671b868d.1750113335.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2024-11-14T19:29:15+00:00

Cross-merge networking fixes after downstream PR (net-6.12-rc8). Conflicts: tools/testing/selftests/net/.gitignore 252e01e68241 ("selftests: net: add netlink-dumps to .gitignore") be43a6b23829 ("selftests: ncdevmem: Move ncdevmem under drivers/net/hw") https://lore.kernel.org/all/20241113122359.1b95180a@canb.auug.org.au/ drivers/net/phy/phylink.c 671154f174e0 ("net: phylink: ensure PHY momentary link-fails are handled") 7530ea26c810 ("net: phylink: remove "using_mac_select_pcs"") Adjacent changes: drivers/net/ethernet/stmicro/stmmac/dwmac-intel-plat.c 5b366eae7193 ("stmmac: dwmac-intel-plat: fix call balance of tx_clk handling routines") e96321fad3ad ("net: ethernet: Switch back to struct platform_driver::remove()") Signed-off-by: Jakub Kicinski