kernel/linux.git/include/linux/skbuff.h, branch linux-6.9.y

inet: introduce dst_rtable() helper

2024-06-12T09:39:55+00:00

[ Upstream commit 05d6d492097c55f2d153fc3fd33cbe78e1e28e0a ] I added dst_rt6_info() in commit e8dfd42c17fa ("ipv6: introduce dst_rt6_info() helper") This patch does a similar change for IPv4. Instead of (struct rtable *)dst casts, we can use : #define dst_rtable(_ptr) \ container_of_const(_ptr, struct rtable, dst) Patch is smaller than IPv6 one, because IPv4 has skb_rtable() helper. Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Reviewed-by: Sabrina Dubroca Link: https://lore.kernel.org/r/20240429133009.1227754-1-edumazet@google.com Signed-off-by: Jakub Kicinski Stable-dep-of: 92f1655aa2b2 ("net: fix __dst_negative_advice() race") Signed-off-by: Sasha Levin

xfrm: Preserve vlan tags for transport mode software GRO

2024-04-26T04:44:33+00:00

The software GRO path for esp transport mode uses skb_mac_header_rebuild prior to re-injecting the packet via the xfrm_napi_dev. This only copies skb->mac_len bytes of header which may not be sufficient if the packet contains 802.1Q tags or other VLAN tags. Worse copying only the initial header will leave a packet marked as being VLAN tagged but without the corresponding tag leading to mangling when it is later untagged. The VLAN tags are important when receiving the decrypted esp transport mode packet after GRO processing to ensure it is received on the correct interface. Therefore record the full mac header length in xfrm*_transport_input for later use in corresponding xfrm*_transport_finish to copy the entire mac header when rebuilding the mac header for GRO. The skb->data pointer is left pointing skb->mac_header bytes after the start of the mac header as is expected by the network stack and network and transport header offsets reset to this location. Fixes: 7785bba299a8 ("esp: Add a software GRO codepath") Signed-off-by: Paul Davey Signed-off-by: Steffen Klassert

inet: inet_defrag: prevent sk release while still in use

2024-03-28T11:06:22+00:00

ip_local_out() and other functions can pass skb->sk as function argument. If the skb is a fragment and reassembly happens before such function call returns, the sk must not be released. This affects skb fragments reassembled via netfilter or similar modules, e.g. openvswitch or ct_act.c, when run as part of tx pipeline. Eric Dumazet made an initial analysis of this bug. Quoting Eric: Calling ip_defrag() in output path is also implying skb_orphan(), which is buggy because output path relies on sk not disappearing. A relevant old patch about the issue was : 8282f27449bf ("inet: frag: Always orphan skbs inside ip_defrag()") [..] net/ipv4/ip_output.c depends on skb->sk being set, and probably to an inet socket, not an arbitrary one. If we orphan the packet in ipvlan, then downstream things like FQ packet scheduler will not work properly. We need to change ip_defrag() to only use skb_orphan() when really needed, ie whenever frag_list is going to be used. Eric suggested to stash sk in fragment queue and made an initial patch. However there is a problem with this: If skb is refragmented again right after, ip_do_fragment() will copy head->sk to the new fragments, and sets up destructor to sock_wfree. IOW, we have no choice but to fix up sk_wmem accouting to reflect the fully reassembled skb, else wmem will underflow. This change moves the orphan down into the core, to last possible moment. As ip_defrag_offset is aliased with sk_buff->sk member, we must move the offset into the FRAG_CB, else skb->sk gets clobbered. This allows to delay the orphaning long enough to learn if the skb has to be queued or if the skb is completing the reasm queue. In the former case, things work as before, skb is orphaned. This is safe because skb gets queued/stolen and won't continue past reasm engine. In the latter case, we will steal the skb->sk reference, reattach it to the head skb, and fix up wmem accouting when inet_frag inflates truesize. Fixes: 7026b1ddb6b8 ("netfilter: Pass socket pointer down through okfn().") Diagnosed-by: Eric Dumazet Reported-by: xingwei lee Reported-by: yue sun Reported-by: syzbot+e5167d7144a62715044c@syzkaller.appspotmail.com Signed-off-by: Florian Westphal Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20240326101845.30836-1-fw@strlen.de Signed-off-by: Paolo Abeni

Merge tag 'ipsec-2024-03-19' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2024-03-20T02:44:03+00:00

Steffen Klassert says: ==================== pull request (net): ipsec 2024-03-19 1) Fix possible page_pool leak triggered by esp_output. From Dragos Tatulea. 2) Fix UDP encapsulation in software GSO path. From Leon Romanovsky. * tag 'ipsec-2024-03-19' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec: xfrm: Allow UDP encapsulation only in offload modes net: esp: fix bad handling of pages from page_pool ==================== Link: https://lore.kernel.org/r/20240319110151.409825-1-steffen.klassert@secunet.com Signed-off-by: Jakub Kicinski

Revert "net: Re-use and set mono_delivery_time bit for userspace tstamp packets"

2024-03-18T12:29:53+00:00

This reverts commit 885c36e59f46375c138de18ff1692f18eff67b7f. The patch currently broke the bpf selftest test_tc_dtime because uapi field __sk_buff->tstamp_type depends on skb->mono_delivery_time which does not necessarily mean mono with the original fix as the bit was re-used for userspace timestamp as well to avoid tstamp reset in the forwarding path. To solve this we need to keep mono_delivery_time as is and introduce another bit called user_delivery_time and fall back to the initial proposal of setting the user_delivery_time bit based on sk_clockid set from userspace. Fixes: 885c36e59f46 ("net: Re-use and set mono_delivery_time bit for userspace tstamp packets") Link: https://lore.kernel.org/netdev/bc037db4-58bb-4861-ac31-a361a93841d3@linux.dev/ Signed-off-by: Abhishek Chauhan Acked-by: Daniel Borkmann Acked-by: Martin KaFai Lau Signed-off-by: David S. Miller

net: esp: fix bad handling of pages from page_pool

2024-03-18T10:53:46+00:00

When the skb is reorganized during esp_output (!esp->inline), the pages coming from the original skb fragments are supposed to be released back to the system through put_page. But if the skb fragment pages are originating from a page_pool, calling put_page on them will trigger a page_pool leak which will eventually result in a crash. This leak can be easily observed when using CONFIG_DEBUG_VM and doing ipsec + gre (non offloaded) forwarding: BUG: Bad page state in process ksoftirqd/16 pfn:1451b6 page:00000000de2b8d32 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1451b6000 pfn:0x1451b6 flags: 0x200000000000000(node=0|zone=2) page_type: 0xffffffff() raw: 0200000000000000 dead000000000040 ffff88810d23c000 0000000000000000 raw: 00000001451b6000 0000000000000001 00000000ffffffff 0000000000000000 page dumped because: page_pool leak Modules linked in: ip_gre gre mlx5_ib mlx5_core xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink iptable_nat nf_nat xt_addrtype br_netfilter rpcrdma rdma_ucm ib_iser libiscsi scsi_transport_iscsi ib_umad rdma_cm ib_ipoib iw_cm ib_cm ib_uverbs ib_core overlay zram zsmalloc fuse [last unloaded: mlx5_core] CPU: 16 PID: 96 Comm: ksoftirqd/16 Not tainted 6.8.0-rc4+ #22 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack_lvl+0x36/0x50 bad_page+0x70/0xf0 free_unref_page_prepare+0x27a/0x460 free_unref_page+0x38/0x120 esp_ssg_unref.isra.0+0x15f/0x200 esp_output_tail+0x66d/0x780 esp_xmit+0x2c5/0x360 validate_xmit_xfrm+0x313/0x370 ? validate_xmit_skb+0x1d/0x330 validate_xmit_skb_list+0x4c/0x70 sch_direct_xmit+0x23e/0x350 __dev_queue_xmit+0x337/0xba0 ? nf_hook_slow+0x3f/0xd0 ip_finish_output2+0x25e/0x580 iptunnel_xmit+0x19b/0x240 ip_tunnel_xmit+0x5fb/0xb60 ipgre_xmit+0x14d/0x280 [ip_gre] dev_hard_start_xmit+0xc3/0x1c0 __dev_queue_xmit+0x208/0xba0 ? nf_hook_slow+0x3f/0xd0 ip_finish_output2+0x1ca/0x580 ip_sublist_rcv_finish+0x32/0x40 ip_sublist_rcv+0x1b2/0x1f0 ? ip_rcv_finish_core.constprop.0+0x460/0x460 ip_list_rcv+0x103/0x130 __netif_receive_skb_list_core+0x181/0x1e0 netif_receive_skb_list_internal+0x1b3/0x2c0 napi_gro_receive+0xc8/0x200 gro_cell_poll+0x52/0x90 __napi_poll+0x25/0x1a0 net_rx_action+0x28e/0x300 __do_softirq+0xc3/0x276 ? sort_range+0x20/0x20 run_ksoftirqd+0x1e/0x30 smpboot_thread_fn+0xa6/0x130 kthread+0xcd/0x100 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x31/0x50 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork_asm+0x11/0x20 The suggested fix is to introduce a new wrapper (skb_page_unref) that covers page refcounting for page_pool pages as well. Cc: stable@vger.kernel.org Fixes: 6a5bcd84e886 ("page_pool: Allow drivers to hint on SKB recycling") Reported-and-tested-by: Anatoli N.Chechelnickiy Reported-by: Ian Kumlien Link: https://lore.kernel.org/netdev/CAA85sZvvHtrpTQRqdaOx6gd55zPAVsqMYk_Lwh4Md5knTq7AyA@mail.gmail.com Signed-off-by: Dragos Tatulea Reviewed-by: Mina Almasry Reviewed-by: Jakub Kicinski Acked-by: Ilias Apalodimas Signed-off-by: Steffen Klassert

net: add skb_data_unref() helper

2024-03-08T19:38:45+00:00

Similar to skb_unref(), add skb_data_unref() to save an expensive atomic operation (and cache line dirtying) when last reference on shinfo->dataref is released. I saw this opportunity on hosts with RAW sockets accidentally bound to UDP protocol, forcing an skb_clone() on all received packets. These RAW sockets had their receive queue full, so all clone packets were immediately dropped. When UDP recvmsg() consumes later the original skb, skb_release_data() is hitting atomic_sub_return() quite badly, because skb->clone has been set permanently. Note that this patch helps TCP TX performance, because TCP stack also use (fast) clones. This means that at least one of the two packets (the main skb or its clone) will no longer have to perform this atomic operation in skb_release_data(). Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20240307123446.2302230-1-edumazet@google.com Signed-off-by: Jakub Kicinski

net: move skbuff_cache(s) to net_hotdata

2024-03-08T05:12:42+00:00

skbuff_cache, skbuff_fclone_cache and skb_small_head_cache are used in rx/tx fast paths. Move them to net_hotdata for better cache locality. Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240306160031.874438-11-edumazet@google.com Signed-off-by: Jakub Kicinski

net: Re-use and set mono_delivery_time bit for userspace tstamp packets

2024-03-05T12:41:16+00:00

Bridge driver today has no support to forward the userspace timestamp packets and ends up resetting the timestamp. ETF qdisc checks the packet coming from userspace and encounters to be 0 thereby dropping time sensitive packets. These changes will allow userspace timestamps packets to be forwarded from the bridge to NIC drivers. Setting the same bit (mono_delivery_time) to avoid dropping of userspace tstamp packets in the forwarding path. Existing functionality of mono_delivery_time remains unaltered here, instead just extended with userspace tstamp support for bridge forwarding path. Signed-off-by: Abhishek Chauhan Reviewed-by: Willem de Bruijn Link: https://lore.kernel.org/r/20240301201348.2815102-1-quic_abchauha@quicinc.com Signed-off-by: Paolo Abeni

net: adopt skb_network_header_len() more broadly

2024-03-04T08:47:06+00:00

(skb_transport_header(skb) - skb_network_header(skb)) can be replaced by skb_network_header_len(skb) Add a DEBUG_NET_WARN_ON_ONCE() in skb_network_header_len() to catch cases were the transport_header was not set. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller