kernel/linux.git/net/core, branch v6.1.168

net: correctly handle tunneled traffic on IPV6_CSUM GSO fallback

2026-04-11T12:16:34+00:00

[ Upstream commit c4336a07eb6b2526dc2b62928b5104b41a7f81f5 ] NETIF_F_IPV6_CSUM only advertises support for checksum offload of packets without IPv6 extension headers. Packets with extension headers must fall back onto software checksumming. Since TSO depends on checksum offload, those must revert to GSO. The below commit introduces that fallback. It always checks network header length. For tunneled packets, the inner header length must be checked instead. Extend the check accordingly. A special case is tunneled packets without inner IP protocol. Such as RFC 6951 SCTP in UDP. Those are not standard IPv6 followed by transport header either, so also must revert to the software GSO path. Cc: stable@vger.kernel.org Fixes: 864e3396976e ("net: gso: Forbid IPv6 TSO with extensions on devices with only IPV6_CSUM") Reported-by: Tangxin Xie Closes: https://lore.kernel.org/netdev/0414e7e2-9a1c-4d7c-a99d-b9039cf68f40@yeah.net/ Suggested-by: Paolo Abeni Signed-off-by: Willem de Bruijn Link: https://patch.msgid.link/20260320190148.2409107-1-willemdebruijn.kernel@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

rtnetlink: count IFLA_INFO_SLAVE_KIND in if_nlmsg_size

2026-04-11T12:16:07+00:00

[ Upstream commit ee00a12593ffb69db4dd1a1c00ecb0253376874a ] rtnl_link_get_slave_info_data_size counts IFLA_INFO_SLAVE_DATA, but rtnl_link_slave_info_fill adds both IFLA_INFO_SLAVE_DATA and IFLA_INFO_SLAVE_KIND. Fixes: ba7d49b1f0f8 ("rtnetlink: provide api for getting and setting slave info") Reviewed-by: Jiri Pirko Signed-off-by: Sabrina Dubroca Link: https://patch.msgid.link/049843b532e23cde7ddba263c0bbe35ba6f0d26d.1773919462.git.sd@queasysnail.net Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

rtnetlink: Honour NLM_F_ECHO flag in rtnl_delete_link

2026-04-11T12:16:07+00:00

[ Upstream commit f3a63cce1b4fbde7738395c5a2dea83f05de3407 ] This patch use the new helper unregister_netdevice_many_notify() for rtnl_delete_link(), so that the kernel could reply unicast when userspace set NLM_F_ECHO flag to request the new created interface info. At the same time, the parameters of rtnl_delete_link() need to be updated since we need nlmsghdr and portid info. Suggested-by: Guillaume Nault Signed-off-by: Hangbin Liu Reviewed-by: Guillaume Nault Signed-off-by: Jakub Kicinski Stable-dep-of: 6931d21f87bc ("openvswitch: defer tunnel netdev_put to RCU release") Signed-off-by: Sasha Levin

net: add new helper unregister_netdevice_many_notify

2026-04-11T12:16:06+00:00

[ Upstream commit 77f4aa9a2a1766a0b9343fd812b71f18d05178da ] Add new helper unregister_netdevice_many_notify(), pass netlink message header and portid, which could be used to notify userspace when flag NLM_F_ECHO is set. Make the unregister_netdevice_many() as a wrapper of new function unregister_netdevice_many_notify(). Suggested-by: Guillaume Nault Signed-off-by: Hangbin Liu Reviewed-by: Guillaume Nault Signed-off-by: Jakub Kicinski Stable-dep-of: 6931d21f87bc ("openvswitch: defer tunnel netdev_put to RCU release") Signed-off-by: Sasha Levin

rtnetlink: pass netlink message header and portid to rtnl_configure_link()

2026-04-11T12:16:06+00:00

[ Upstream commit 1d997f1013079c05b642c739901e3584a3ae558d ] This patch pass netlink message header and portid to rtnl_configure_link() All the functions in this call chain need to add the parameters so we can use them in the last call rtnl_notify(), and notify the userspace about the new link info if NLM_F_ECHO flag is set. - rtnl_configure_link() - __dev_notify_flags() - rtmsg_ifinfo() - rtmsg_ifinfo_event() - rtmsg_ifinfo_build_skb() - rtmsg_ifinfo_send() - rtnl_notify() Also move __dev_notify_flags() declaration to net/core/dev.h, as Jakub suggested. Signed-off-by: Hangbin Liu Reviewed-by: Guillaume Nault Signed-off-by: Jakub Kicinski Stable-dep-of: 6931d21f87bc ("openvswitch: defer tunnel netdev_put to RCU release") Signed-off-by: Sasha Levin

net: fix segmentation of forwarding fraglist GRO

2026-03-25T10:03:24+00:00

[ Upstream commit 426ca15c7f6cb6562a081341ca88893a50c59fa2 ] This patch enhances GSO segment handling by properly checking the SKB_GSO_DODGY flag for frag_list GSO packets, addressing low throughput issues observed when a station accesses IPv4 servers via hotspots with an IPv6-only upstream interface. Specifically, it fixes a bug in GSO segmentation when forwarding GRO packets containing a frag_list. The function skb_segment_list cannot correctly process GRO skbs that have been converted by XLAT, since XLAT only translates the header of the head skb. Consequently, skbs in the frag_list may remain untranslated, resulting in protocol inconsistencies and reduced throughput. To address this, the patch explicitly sets the SKB_GSO_DODGY flag for GSO packets in XLAT's IPv4/IPv6 protocol translation helpers (bpf_skb_proto_4_to_6 and bpf_skb_proto_6_to_4). This marks GSO packets as potentially modified after protocol translation. As a result, GSO segmentation will avoid using skb_segment_list and instead falls back to skb_segment for packets with the SKB_GSO_DODGY flag. This ensures that only safe and fully translated frag_list packets are processed by skb_segment_list, resolving protocol inconsistencies and improving throughput when forwarding GRO packets converted by XLAT. Signed-off-by: Jibin Zhang Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260126152114.1211-1-jibin.zhang@mediatek.com Signed-off-by: Paolo Abeni Signed-off-by: Li hongliang <1468888505@139.com> Signed-off-by: Greg Kroah-Hartman

net: clear the dst when changing skb protocol

2026-03-25T10:03:24+00:00

commit ba9db6f907ac02215e30128770f85fbd7db2fcf9 upstream. A not-so-careful NAT46 BPF program can crash the kernel if it indiscriminately flips ingress packets from v4 to v6: BUG: kernel NULL pointer dereference, address: 0000000000000000 ip6_rcv_core (net/ipv6/ip6_input.c:190:20) ipv6_rcv (net/ipv6/ip6_input.c:306:8) process_backlog (net/core/dev.c:6186:4) napi_poll (net/core/dev.c:6906:9) net_rx_action (net/core/dev.c:7028:13) do_softirq (kernel/softirq.c:462:3) netif_rx (net/core/dev.c:5326:3) dev_loopback_xmit (net/core/dev.c:4015:2) ip_mc_finish_output (net/ipv4/ip_output.c:363:8) NF_HOOK (./include/linux/netfilter.h:314:9) ip_mc_output (net/ipv4/ip_output.c:400:5) dst_output (./include/net/dst.h:459:9) ip_local_out (net/ipv4/ip_output.c:130:9) ip_send_skb (net/ipv4/ip_output.c:1496:8) udp_send_skb (net/ipv4/udp.c:1040:8) udp_sendmsg (net/ipv4/udp.c:1328:10) The output interface has a 4->6 program attached at ingress. We try to loop the multicast skb back to the sending socket. Ingress BPF runs as part of netif_rx(), pushes a valid v6 hdr and changes skb->protocol to v6. We enter ip6_rcv_core which tries to use skb_dst(). But the dst is still an IPv4 one left after IPv4 mcast output. Clear the dst in all BPF helpers which change the protocol. Try to preserve metadata dsts, those may carry non-routing metadata. Cc: stable@vger.kernel.org Reviewed-by: Maciej Żenczykowski Acked-by: Daniel Borkmann Fixes: d219df60a70e ("bpf: Add ipip6 and ip6ip decap support for bpf_skb_adjust_room()") Fixes: 1b00e0dfe7d0 ("bpf: update skb->protocol in bpf_skb_net_grow") Fixes: 6578171a7ff0 ("bpf: add bpf_skb_change_proto helper") Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250610001245.1981782-1-kuba@kernel.org Signed-off-by: Jakub Kicinski [ The context change is due to the commit d219df60a70e ("bpf: Add ipip6 and ip6ip decap support for bpf_skb_adjust_room()") in v6.3 which is irrelevant to the logic of this patch. ] Signed-off-by: Johnny Hao Signed-off-by: Greg Kroah-Hartman

net: Handle napi_schedule() calls from non-interrupt

2026-03-25T10:03:19+00:00

commit 77e45145e3039a0fb212556ab3f8c87f54771757 upstream. napi_schedule() is expected to be called either: * From an interrupt, where raised softirqs are handled on IRQ exit * From a softirq disabled section, where raised softirqs are handled on the next call to local_bh_enable(). * From a softirq handler, where raised softirqs are handled on the next round in do_softirq(), or further deferred to a dedicated kthread. Other bare tasks context may end up ignoring the raised NET_RX vector until the next random softirq handling opportunity, which may not happen before a while if the CPU goes idle afterwards with the tick stopped. Such "misuses" have been detected on several places thanks to messages of the kind: "NOHZ tick-stop error: local softirq work is pending, handler #08!!!" For example: __raise_softirq_irqoff __napi_schedule rtl8152_runtime_resume.isra.0 rtl8152_resume usb_resume_interface.isra.0 usb_resume_both __rpm_callback rpm_callback rpm_resume __pm_runtime_resume usb_autoresume_device usb_remote_wakeup hub_event process_one_work worker_thread kthread ret_from_fork ret_from_fork_asm And also: * drivers/net/usb/r8152.c::rtl_work_func_t * drivers/net/netdevsim/netdev.c::nsim_start_xmit There is a long history of issues of this kind: 019edd01d174 ("ath10k: sdio: Add missing BH locking around napi_schdule()") 330068589389 ("idpf: disable local BH when scheduling napi for marker packets") e3d5d70cb483 ("net: lan78xx: fix "softirq work is pending" error") e55c27ed9ccf ("mt76: mt7615: add missing bh-disable around rx napi schedule") c0182aa98570 ("mt76: mt7915: add missing bh-disable around tx napi enable/schedule") 970be1dff26d ("mt76: disable BH around napi_schedule() calls") 019edd01d174 ("ath10k: sdio: Add missing BH locking around napi_schdule()") 30bfec4fec59 ("can: rx-offload: can_rx_offload_threaded_irq_finish(): add new function to be called from threaded interrupt") e63052a5dd3c ("mlx5e: add add missing BH locking around napi_schdule()") 83a0c6e58901 ("i40e: Invoke softirqs after napi_reschedule") bd4ce941c8d5 ("mlx4: Invoke softirqs after napi_reschedule") 8cf699ec849f ("mlx4: do not call napi_schedule() without care") ec13ee80145c ("virtio_net: invoke softirqs after __napi_schedule") This shows that relying on the caller to arrange a proper context for the softirqs to be handled while calling napi_schedule() is very fragile and error prone. Also fixing them can also prove challenging if the caller may be called from different kinds of contexts. Therefore fix this from napi_schedule() itself with waking up ksoftirqd when softirqs are raised from task contexts. Reported-by: Paul Menzel Reported-by: Jakub Kicinski Reported-by: Francois Romieu Closes: https://lore.kernel.org/lkml/354a2690-9bbf-4ccb-8769-fa94707a9340@molgen.mpg.de/ Cc: Breno Leitao Signed-off-by: Frederic Weisbecker Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20250223221708.27130-1-frederic@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Jan Kiszka Signed-off-by: Greg Kroah-Hartman

xdp: produce a warning when calculated tailroom is negative

2026-03-25T10:03:02+00:00

[ Upstream commit 8821e857759be9db3cde337ad328b71fe5c8a55f ] Many ethernet drivers report xdp Rx queue frag size as being the same as DMA write size. However, the only user of this field, namely bpf_xdp_frags_increase_tail(), clearly expects a truesize. Such difference leads to unspecific memory corruption issues under certain circumstances, e.g. in ixgbevf maximum DMA write size is 3 KB, so when running xskxceiver's XDP_ADJUST_TAIL_GROW_MULTI_BUFF, 6K packet fully uses all DMA-writable space in 2 buffers. This would be fine, if only rxq->frag_size was properly set to 4K, but value of 3K results in a negative tailroom, because there is a non-zero page offset. We are supposed to return -EINVAL and be done with it in such case, but due to tailroom being stored as an unsigned int, it is reported to be somewhere near UINT_MAX, resulting in a tail being grown, even if the requested offset is too much (it is around 2K in the abovementioned test). This later leads to all kinds of unspecific calltraces. [ 7340.337579] xskxceiver[1440]: segfault at 1da718 ip 00007f4161aeac9d sp 00007f41615a6a00 error 6 [ 7340.338040] xskxceiver[1441]: segfault at 7f410000000b ip 00000000004042b5 sp 00007f415bffecf0 error 4 [ 7340.338179] in libc.so.6[61c9d,7f4161aaf000+160000] [ 7340.339230] in xskxceiver[42b5,400000+69000] [ 7340.340300] likely on CPU 6 (core 0, socket 6) [ 7340.340302] Code: ff ff 01 e9 f4 fe ff ff 0f 1f 44 00 00 4c 39 f0 74 73 31 c0 ba 01 00 00 00 f0 0f b1 17 0f 85 ba 00 00 00 49 8b 87 88 00 00 00 <4c> 89 70 08 eb cc 0f 1f 44 00 00 48 8d bd f0 fe ff ff 89 85 ec fe [ 7340.340888] likely on CPU 3 (core 0, socket 3) [ 7340.345088] Code: 00 00 00 ba 00 00 00 00 be 00 00 00 00 89 c7 e8 31 ca ff ff 89 45 ec 8b 45 ec 85 c0 78 07 b8 00 00 00 00 eb 46 e8 0b c8 ff ff <8b> 00 83 f8 69 74 24 e8 ff c7 ff ff 8b 00 83 f8 0b 74 18 e8 f3 c7 [ 7340.404334] Oops: general protection fault, probably for non-canonical address 0x6d255010bdffc: 0000 [#1] SMP NOPTI [ 7340.405972] CPU: 7 UID: 0 PID: 1439 Comm: xskxceiver Not tainted 6.19.0-rc1+ #21 PREEMPT(lazy) [ 7340.408006] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-5.fc42 04/01/2014 [ 7340.409716] RIP: 0010:lookup_swap_cgroup_id+0x44/0x80 [ 7340.410455] Code: 83 f8 1c 73 39 48 ba ff ff ff ff ff ff ff 03 48 8b 04 c5 20 55 fa bd 48 21 d1 48 89 ca 83 e1 01 48 d1 ea c1 e1 04 48 8d 04 90 <8b> 00 48 83 c4 10 d3 e8 c3 cc cc cc cc 31 c0 e9 98 b7 dd 00 48 89 [ 7340.412787] RSP: 0018:ffffcc5c04f7f6d0 EFLAGS: 00010202 [ 7340.413494] RAX: 0006d255010bdffc RBX: ffff891f477895a8 RCX: 0000000000000010 [ 7340.414431] RDX: 0001c17e3fffffff RSI: 00fa070000000000 RDI: 000382fc7fffffff [ 7340.415354] RBP: 00fa070000000000 R08: ffffcc5c04f7f8f8 R09: ffffcc5c04f7f7d0 [ 7340.416283] R10: ffff891f4c1a7000 R11: ffffcc5c04f7f9c8 R12: ffffcc5c04f7f7d0 [ 7340.417218] R13: 03ffffffffffffff R14: 00fa06fffffffe00 R15: ffff891f47789500 [ 7340.418229] FS: 0000000000000000(0000) GS:ffff891ffdfaa000(0000) knlGS:0000000000000000 [ 7340.419489] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 7340.420286] CR2: 00007f415bfffd58 CR3: 0000000103f03002 CR4: 0000000000772ef0 [ 7340.421237] PKRU: 55555554 [ 7340.421623] Call Trace: [ 7340.421987] [ 7340.422309] ? softleaf_from_pte+0x77/0xa0 [ 7340.422855] swap_pte_batch+0xa7/0x290 [ 7340.423363] zap_nonpresent_ptes.constprop.0.isra.0+0xd1/0x270 [ 7340.424102] zap_pte_range+0x281/0x580 [ 7340.424607] zap_pmd_range.isra.0+0xc9/0x240 [ 7340.425177] unmap_page_range+0x24d/0x420 [ 7340.425714] unmap_vmas+0xa1/0x180 [ 7340.426185] exit_mmap+0xe1/0x3b0 [ 7340.426644] __mmput+0x41/0x150 [ 7340.427098] exit_mm+0xb1/0x110 [ 7340.427539] do_exit+0x1b2/0x460 [ 7340.427992] do_group_exit+0x2d/0xc0 [ 7340.428477] get_signal+0x79d/0x7e0 [ 7340.428957] arch_do_signal_or_restart+0x34/0x100 [ 7340.429571] exit_to_user_mode_loop+0x8e/0x4c0 [ 7340.430159] do_syscall_64+0x188/0x6b0 [ 7340.430672] ? __do_sys_clone3+0xd9/0x120 [ 7340.431212] ? switch_fpu_return+0x4e/0xd0 [ 7340.431761] ? arch_exit_to_user_mode_prepare.isra.0+0xa1/0xc0 [ 7340.432498] ? do_syscall_64+0xbb/0x6b0 [ 7340.433015] ? __handle_mm_fault+0x445/0x690 [ 7340.433582] ? count_memcg_events+0xd6/0x210 [ 7340.434151] ? handle_mm_fault+0x212/0x340 [ 7340.434697] ? do_user_addr_fault+0x2b4/0x7b0 [ 7340.435271] ? clear_bhb_loop+0x30/0x80 [ 7340.435788] ? clear_bhb_loop+0x30/0x80 [ 7340.436299] ? clear_bhb_loop+0x30/0x80 [ 7340.436812] ? clear_bhb_loop+0x30/0x80 [ 7340.437323] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 7340.437973] RIP: 0033:0x7f4161b14169 [ 7340.438468] Code: Unable to access opcode bytes at 0x7f4161b1413f. [ 7340.439242] RSP: 002b:00007ffc6ebfa770 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 7340.440173] RAX: fffffffffffffe00 RBX: 00000000000005a1 RCX: 00007f4161b14169 [ 7340.441061] RDX: 00000000000005a1 RSI: 0000000000000109 RDI: 00007f415bfff990 [ 7340.441943] RBP: 00007ffc6ebfa7a0 R08: 0000000000000000 R09: 00000000ffffffff [ 7340.442824] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 7340.443707] R13: 0000000000000000 R14: 00007f415bfff990 R15: 00007f415bfff6c0 [ 7340.444586] [ 7340.444922] Modules linked in: rfkill intel_rapl_msr intel_rapl_common intel_uncore_frequency_common skx_edac_common nfit libnvdimm kvm_intel vfat fat kvm snd_pcm irqbypass rapl iTCO_wdt snd_timer intel_pmc_bxt iTCO_vendor_support snd ixgbevf virtio_net soundcore i2c_i801 pcspkr libeth_xdp net_failover i2c_smbus lpc_ich failover libeth virtio_balloon joydev 9p fuse loop zram lz4hc_compress lz4_compress 9pnet_virtio 9pnet netfs ghash_clmulni_intel serio_raw qemu_fw_cfg [ 7340.449650] ---[ end trace 0000000000000000 ]--- The issue can be fixed in all in-tree drivers, but we cannot just trust OOT drivers to not do this. Therefore, make tailroom a signed int and produce a warning when it is negative to prevent such mistakes in the future. Fixes: bf25146a5595 ("bpf: add frags support to the bpf_xdp_adjust_tail() API") Reviewed-by: Aleksandr Loktionov Reviewed-by: Toke Høiland-Jørgensen Acked-by: Martin KaFai Lau Signed-off-by: Larysa Zaremba Link: https://patch.msgid.link/20260305111253.2317394-10-larysa.zaremba@intel.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

xdp: use modulo operation to calculate XDP frag tailroom

2026-03-25T10:03:02+00:00

[ Upstream commit 88b6b7f7b216108a09887b074395fa7b751880b1 ] The current formula for calculating XDP tailroom in mbuf packets works only if each frag has its own page (if rxq->frag_size is PAGE_SIZE), this defeats the purpose of the parameter overall and without any indication leads to negative calculated tailroom on at least half of frags, if shared pages are used. There are not many drivers that set rxq->frag_size. Among them: * i40e and enetc always split page uniformly between frags, use shared pages * ice uses page_pool frags via libeth, those are power-of-2 and uniformly distributed across page * idpf has variable frag_size with XDP on, so current API is not applicable * mlx5, mtk and mvneta use PAGE_SIZE or 0 as frag_size for page_pool As for AF_XDP ZC, only ice, i40e and idpf declare frag_size for it. Modulo operation yields good results for aligned chunks, they are all power-of-2, between 2K and PAGE_SIZE. Formula without modulo fails when chunk_size is 2K. Buffers in unaligned mode are not distributed uniformly, so modulo operation would not work. To accommodate unaligned buffers, we could define frag_size as data + tailroom, and hence do not subtract offset when calculating tailroom, but this would necessitate more changes in the drivers. Define rxq->frag_size as an even portion of a page that fully belongs to a single frag. When calculating tailroom, locate the data start within such portion by performing a modulo operation on page offset. Fixes: bf25146a5595 ("bpf: add frags support to the bpf_xdp_adjust_tail() API") Acked-by: Jakub Kicinski Reviewed-by: Aleksandr Loktionov Signed-off-by: Larysa Zaremba Link: https://patch.msgid.link/20260305111253.2317394-2-larysa.zaremba@intel.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin