linux/net/ipv6, branch v6.17

ipv6: annotate data-races around devconf->rpl_seg_enabled

2025-09-03T00:01:06Z

devconf->rpl_seg_enabled can be changed concurrently from /proc/sys/net/ipv6/conf, annotate lockless reads on it. Signed-off-by: Yue Haibing Link: https://patch.msgid.link/20250901123726.1972881-2-yuehaibing@huawei.com Signed-off-by: Jakub Kicinski

net/tcp: Fix socket memory leak in TCP-AO failure handling for IPv6

2025-09-02T22:58:22Z

When tcp_ao_copy_all_matching() fails in tcp_v6_syn_recv_sock() it just exits the function. This ends up causing a memory-leak: unreferenced object 0xffff0000281a8200 (size 2496): comm "softirq", pid 0, jiffies 4295174684 hex dump (first 32 bytes): 7f 00 00 06 7f 00 00 06 00 00 00 00 cb a8 88 13 ................ 0a 00 03 61 00 00 00 00 00 00 00 00 00 00 00 00 ...a............ backtrace (crc 5ebdbe15): kmemleak_alloc+0x44/0xe0 kmem_cache_alloc_noprof+0x248/0x470 sk_prot_alloc+0x48/0x120 sk_clone_lock+0x38/0x3b0 inet_csk_clone_lock+0x34/0x150 tcp_create_openreq_child+0x3c/0x4a8 tcp_v6_syn_recv_sock+0x1c0/0x620 tcp_check_req+0x588/0x790 tcp_v6_rcv+0x5d0/0xc18 ip6_protocol_deliver_rcu+0x2d8/0x4c0 ip6_input_finish+0x74/0x148 ip6_input+0x50/0x118 ip6_sublist_rcv+0x2fc/0x3b0 ipv6_list_rcv+0x114/0x170 __netif_receive_skb_list_core+0x16c/0x200 netif_receive_skb_list_internal+0x1f0/0x2d0 This is because in tcp_v6_syn_recv_sock (and the IPv4 counterpart), when exiting upon error, inet_csk_prepare_forced_close() and tcp_done() need to be called. They make sure the newsk will end up being correctly free'd. tcp_v4_syn_recv_sock() makes this very clear by having the put_and_exit label that takes care of things. So, this patch here makes sure tcp_v4_syn_recv_sock and tcp_v6_syn_recv_sock have similar error-handling and thus fixes the leak for TCP-AO. Fixes: 06b22ef29591 ("net/tcp: Wire TCP-AO to request sockets") Signed-off-by: Christoph Paasch Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Link: https://patch.msgid.link/20250830-tcpao_leak-v1-1-e5878c2c3173@openai.com Signed-off-by: Jakub Kicinski

icmp: fix icmp_ndo_send address translation for reply direction

2025-09-01T19:54:41Z

The icmp_ndo_send function was originally introduced to ensure proper rate limiting when icmp_send is called by a network device driver, where the packet's source address may have already been transformed by SNAT. However, the original implementation only considers the IP_CT_DIR_ORIGINAL direction for SNAT and always replaced the packet's source address with that of the original-direction tuple. This causes two problems: 1. For SNAT: Reply-direction packets were incorrectly translated using the source address of the CT original direction, even though no translation is required. 2. For DNAT: Reply-direction packets were not handled at all. In DNAT, the original direction's destination is translated. Therefore, in the reply direction the source address must be set to the reply-direction source, so rate limiting works as intended. Fix this by using the connection direction to select the correct tuple for source address translation, and adjust the pre-checks to handle reply-direction packets in case of DNAT. Additionally, wrap the `ct->status` access in READ_ONCE(). This avoids possible KCSAN reports about concurrent updates to `ct->status`. Fixes: 0b41713b6066 ("icmp: introduce helper for nat'd source address in network device context") Signed-off-by: Fabian Bläse Cc: Jason A. Donenfeld Reviewed-by: Florian Westphal Signed-off-by: Jakub Kicinski

netfilter: nf_reject: don't leak dst refcount for loopback packets

2025-08-21T17:02:00Z

recent patches to add a WARN() when replacing skb dst entry found an old bug: WARNING: include/linux/skbuff.h:1165 skb_dst_check_unset include/linux/skbuff.h:1164 [inline] WARNING: include/linux/skbuff.h:1165 skb_dst_set include/linux/skbuff.h:1210 [inline] WARNING: include/linux/skbuff.h:1165 nf_reject_fill_skb_dst+0x2a4/0x330 net/ipv4/netfilter/nf_reject_ipv4.c:234 [..] Call Trace: nf_send_unreach+0x17b/0x6e0 net/ipv4/netfilter/nf_reject_ipv4.c:325 nft_reject_inet_eval+0x4bc/0x690 net/netfilter/nft_reject_inet.c:27 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] .. This is because blamed commit forgot about loopback packets. Such packets already have a dst_entry attached, even at PRE_ROUTING stage. Instead of checking hook just check if the skb already has a route attached to it. Fixes: f53b9b0bdc59 ("netfilter: introduce support for reject at prerouting stage") Signed-off-by: Florian Westphal Link: https://patch.msgid.link/20250820123707.10671-1-fw@strlen.de Signed-off-by: Jakub Kicinski

ipv6: sr: Fix MAC comparison to be constant-time

2025-08-21T02:32:30Z

To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this. Fixes: bf355b8d2c30 ("ipv6: sr: add core files for SR HMAC support") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Reviewed-by: Andrea Mayer Link: https://patch.msgid.link/20250818202724.15713-1-ebiggers@kernel.org Signed-off-by: Jakub Kicinski

ipv6: sr: validate HMAC algorithm ID in seg6_hmac_info_add

2025-08-19T00:35:50Z

The seg6_genl_sethmac() directly uses the algorithm ID provided by the userspace without verifying whether it is an HMAC algorithm supported by the system. If an unsupported HMAC algorithm ID is configured, packets using SRv6 HMAC will be dropped during encapsulation or decapsulation. Fixes: 4f4853dc1c9c ("ipv6: sr: implement API to control SR HMAC structure") Signed-off-by: Minhong He Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250815063845.85426-1-heminhong@kylinos.cn Signed-off-by: Jakub Kicinski

Merge tag 'ipsec-2025-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2025-08-12T13:01:09Z

Steffen Klassert says: ==================== pull request (net): ipsec 2025-08-11 1) Fix flushing of all states in xfrm_state_fini. From Sabrina Dubroca. 2) Fix some IPsec software offload features. These got lost with some recent HW offload changes. From Sabrina Dubroca. Please pull or let me know if there are problems. * tag 'ipsec-2025-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec: udp: also consider secpath when evaluating ipsec use for checksumming xfrm: bring back device check in validate_xmit_xfrm xfrm: restore GSO for SW crypto xfrm: flush all states in xfrm_state_fini ==================== Link: https://patch.msgid.link/20250811092008.731573-1-steffen.klassert@secunet.com Signed-off-by: Paolo Abeni

netfilter: add back NETFILTER_XTABLES dependencies

2025-08-07T11:19:25Z

Some Kconfig symbols were changed to depend on the 'bool' symbol NETFILTER_XTABLES_LEGACY, which means they can now be set to built-in when the xtables code itself is in a loadable module: x86_64-linux-ld: vmlinux.o: in function `arpt_unregister_table_pre_exit': (.text+0x1831987): undefined reference to `xt_find_table' x86_64-linux-ld: vmlinux.o: in function `get_info.constprop.0': arp_tables.c:(.text+0x1831aab): undefined reference to `xt_request_find_table_lock' x86_64-linux-ld: arp_tables.c:(.text+0x1831bea): undefined reference to `xt_table_unlock' x86_64-linux-ld: vmlinux.o: in function `do_arpt_get_ctl': arp_tables.c:(.text+0x183205d): undefined reference to `xt_find_table_lock' x86_64-linux-ld: arp_tables.c:(.text+0x18320c1): undefined reference to `xt_table_unlock' x86_64-linux-ld: arp_tables.c:(.text+0x183219a): undefined reference to `xt_recseq' Change these to depend on both NETFILTER_XTABLES and NETFILTER_XTABLES_LEGACY. Fixes: 9fce66583f06 ("netfilter: Exclude LEGACY TABLES on PREEMPT_RT.") Signed-off-by: Arnd Bergmann Acked-by: Florian Westphal Tested-by: Breno Leitao Signed-off-by: Pablo Neira Ayuso

xfrm: flush all states in xfrm_state_fini

2025-08-06T07:23:38Z

While reverting commit f75a2804da39 ("xfrm: destroy xfrm_state synchronously on net exit path"), I incorrectly changed xfrm_state_flush's "proto" argument back to IPSEC_PROTO_ANY. This reverts some of the changes in commit dbb2483b2a46 ("xfrm: clean up xfrm protocol checks"), and leads to some states not being removed when we exit the netns. Pass 0 instead of IPSEC_PROTO_ANY from both xfrm_state_fini xfrm6_tunnel_net_exit, so that xfrm_state_flush deletes all states. Fixes: 2a198bbec691 ("Revert "xfrm: destroy xfrm_state synchronously on net exit path"") Reported-by: syzbot+6641a61fe0e2e89ae8c5@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=6641a61fe0e2e89ae8c5 Tested-by: syzbot+6641a61fe0e2e89ae8c5@syzkaller.appspotmail.com Signed-off-by: Sabrina Dubroca Reviewed-by: Simon Horman Signed-off-by: Steffen Klassert

ipv6: reject malicious packets in ipv6_gso_segment()

2025-08-01T21:40:53Z

syzbot was able to craft a packet with very long IPv6 extension headers leading to an overflow of skb->transport_header. This 16bit field has a limited range. Add skb_reset_transport_header_careful() helper and use it from ipv6_gso_segment() WARNING: CPU: 0 PID: 5871 at ./include/linux/skbuff.h:3032 skb_reset_transport_header include/linux/skbuff.h:3032 [inline] WARNING: CPU: 0 PID: 5871 at ./include/linux/skbuff.h:3032 ipv6_gso_segment+0x15e2/0x21e0 net/ipv6/ip6_offload.c:151 Modules linked in: CPU: 0 UID: 0 PID: 5871 Comm: syz-executor211 Not tainted 6.16.0-rc6-syzkaller-g7abc678e3084 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:skb_reset_transport_header include/linux/skbuff.h:3032 [inline] RIP: 0010:ipv6_gso_segment+0x15e2/0x21e0 net/ipv6/ip6_offload.c:151 Call Trace: skb_mac_gso_segment+0x31c/0x640 net/core/gso.c:53 nsh_gso_segment+0x54a/0xe10 net/nsh/nsh.c:110 skb_mac_gso_segment+0x31c/0x640 net/core/gso.c:53 __skb_gso_segment+0x342/0x510 net/core/gso.c:124 skb_gso_segment include/net/gso.h:83 [inline] validate_xmit_skb+0x857/0x11b0 net/core/dev.c:3950 validate_xmit_skb_list+0x84/0x120 net/core/dev.c:4000 sch_direct_xmit+0xd3/0x4b0 net/sched/sch_generic.c:329 __dev_xmit_skb net/core/dev.c:4102 [inline] __dev_queue_xmit+0x17b6/0x3a70 net/core/dev.c:4679 Fixes: d1da932ed4ec ("ipv6: Separate ipv6 offload support") Reported-by: syzbot+af43e647fd835acc02df@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/688a1a05.050a0220.5d226.0008.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Reviewed-by: Dawid Osuchowski Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250730131738.3385939-1-edumazet@google.com Signed-off-by: Jakub Kicinski