kernel/linux.git/net/ipv6/ip6_offload.c, branch linux-4.13.y

gso: fix payload length when gso_size is zero

2017-11-18T10:30:35+00:00

[ Upstream commit 3d0241d57c7b25bb75ac9d7a62753642264fdbce ] When gso_size reset to zero for the tail segment in skb_segment(), later in ipv6_gso_segment(), __skb_udp_tunnel_segment() and gre_gso_segment() we will get incorrect results (payload length, pcsum) for that segment. inet_gso_segment() already has a check for gso_size before calculating payload. The issue was found with LTP vxlan & gre tests over ixgbe NIC. Fixes: 07b26c9454a2 ("gso: Support partial splitting at the frag_list pointer") Signed-off-by: Alexey Kodanev Acked-by: Alexander Duyck Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv6: Fix leak in ipv6_gso_segment().

2017-06-05T01:41:10+00:00

If ip6_find_1stfragopt() fails and we return an error we have to free up 'segs' because nobody else is going to. Fixes: 2423496af35d ("ipv6: Prevent overrun when parsing v6 header options") Reported-by: Ben Hutchings Signed-off-by: David S. Miller

ipv6: Check ip6_find_1stfragopt() return value properly.

2017-05-18T02:54:11+00:00

Do not use unsigned variables to see if it returns a negative error or not. Fixes: 2423496af35d ("ipv6: Prevent overrun when parsing v6 header options") Reported-by: Julia Lawall Signed-off-by: David S. Miller

ipv6: Prevent overrun when parsing v6 header options

2017-05-17T18:55:59+00:00

The KASAN warning repoted below was discovered with a syzkaller program. The reproducer is basically: int s = socket(AF_INET6, SOCK_RAW, NEXTHDR_HOP); send(s, &one_byte_of_data, 1, MSG_MORE); send(s, &more_than_mtu_bytes_data, 2000, 0); The socket() call sets the nexthdr field of the v6 header to NEXTHDR_HOP, the first send call primes the payload with a non zero byte of data, and the second send call triggers the fragmentation path. The fragmentation code tries to parse the header options in order to figure out where to insert the fragment option. Since nexthdr points to an invalid option, the calculation of the size of the network header can made to be much larger than the linear section of the skb and data is read outside of it. This fix makes ip6_find_1stfrag return an error if it detects running out-of-bounds. [ 42.361487] ================================================================== [ 42.364412] BUG: KASAN: slab-out-of-bounds in ip6_fragment+0x11c8/0x3730 [ 42.365471] Read of size 840 at addr ffff88000969e798 by task ip6_fragment-oo/3789 [ 42.366469] [ 42.366696] CPU: 1 PID: 3789 Comm: ip6_fragment-oo Not tainted 4.11.0+ #41 [ 42.367628] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-1ubuntu1 04/01/2014 [ 42.368824] Call Trace: [ 42.369183] dump_stack+0xb3/0x10b [ 42.369664] print_address_description+0x73/0x290 [ 42.370325] kasan_report+0x252/0x370 [ 42.370839] ? ip6_fragment+0x11c8/0x3730 [ 42.371396] check_memory_region+0x13c/0x1a0 [ 42.371978] memcpy+0x23/0x50 [ 42.372395] ip6_fragment+0x11c8/0x3730 [ 42.372920] ? nf_ct_expect_unregister_notifier+0x110/0x110 [ 42.373681] ? ip6_copy_metadata+0x7f0/0x7f0 [ 42.374263] ? ip6_forward+0x2e30/0x2e30 [ 42.374803] ip6_finish_output+0x584/0x990 [ 42.375350] ip6_output+0x1b7/0x690 [ 42.375836] ? ip6_finish_output+0x990/0x990 [ 42.376411] ? ip6_fragment+0x3730/0x3730 [ 42.376968] ip6_local_out+0x95/0x160 [ 42.377471] ip6_send_skb+0xa1/0x330 [ 42.377969] ip6_push_pending_frames+0xb3/0xe0 [ 42.378589] rawv6_sendmsg+0x2051/0x2db0 [ 42.379129] ? rawv6_bind+0x8b0/0x8b0 [ 42.379633] ? _copy_from_user+0x84/0xe0 [ 42.380193] ? debug_check_no_locks_freed+0x290/0x290 [ 42.380878] ? ___sys_sendmsg+0x162/0x930 [ 42.381427] ? rcu_read_lock_sched_held+0xa3/0x120 [ 42.382074] ? sock_has_perm+0x1f6/0x290 [ 42.382614] ? ___sys_sendmsg+0x167/0x930 [ 42.383173] ? lock_downgrade+0x660/0x660 [ 42.383727] inet_sendmsg+0x123/0x500 [ 42.384226] ? inet_sendmsg+0x123/0x500 [ 42.384748] ? inet_recvmsg+0x540/0x540 [ 42.385263] sock_sendmsg+0xca/0x110 [ 42.385758] SYSC_sendto+0x217/0x380 [ 42.386249] ? SYSC_connect+0x310/0x310 [ 42.386783] ? __might_fault+0x110/0x1d0 [ 42.387324] ? lock_downgrade+0x660/0x660 [ 42.387880] ? __fget_light+0xa1/0x1f0 [ 42.388403] ? __fdget+0x18/0x20 [ 42.388851] ? sock_common_setsockopt+0x95/0xd0 [ 42.389472] ? SyS_setsockopt+0x17f/0x260 [ 42.390021] ? entry_SYSCALL_64_fastpath+0x5/0xbe [ 42.390650] SyS_sendto+0x40/0x50 [ 42.391103] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 42.391731] RIP: 0033:0x7fbbb711e383 [ 42.392217] RSP: 002b:00007ffff4d34f28 EFLAGS: 00000246 ORIG_RAX: 000000000000002c [ 42.393235] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbbb711e383 [ 42.394195] RDX: 0000000000001000 RSI: 00007ffff4d34f60 RDI: 0000000000000003 [ 42.395145] RBP: 0000000000000046 R08: 00007ffff4d34f40 R09: 0000000000000018 [ 42.396056] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000400aad [ 42.396598] R13: 0000000000000066 R14: 00007ffff4d34ee0 R15: 00007fbbb717af00 [ 42.397257] [ 42.397411] Allocated by task 3789: [ 42.397702] save_stack_trace+0x16/0x20 [ 42.398005] save_stack+0x46/0xd0 [ 42.398267] kasan_kmalloc+0xad/0xe0 [ 42.398548] kasan_slab_alloc+0x12/0x20 [ 42.398848] __kmalloc_node_track_caller+0xcb/0x380 [ 42.399224] __kmalloc_reserve.isra.32+0x41/0xe0 [ 42.399654] __alloc_skb+0xf8/0x580 [ 42.400003] sock_wmalloc+0xab/0xf0 [ 42.400346] __ip6_append_data.isra.41+0x2472/0x33d0 [ 42.400813] ip6_append_data+0x1a8/0x2f0 [ 42.401122] rawv6_sendmsg+0x11ee/0x2db0 [ 42.401505] inet_sendmsg+0x123/0x500 [ 42.401860] sock_sendmsg+0xca/0x110 [ 42.402209] ___sys_sendmsg+0x7cb/0x930 [ 42.402582] __sys_sendmsg+0xd9/0x190 [ 42.402941] SyS_sendmsg+0x2d/0x50 [ 42.403273] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 42.403718] [ 42.403871] Freed by task 1794: [ 42.404146] save_stack_trace+0x16/0x20 [ 42.404515] save_stack+0x46/0xd0 [ 42.404827] kasan_slab_free+0x72/0xc0 [ 42.405167] kfree+0xe8/0x2b0 [ 42.405462] skb_free_head+0x74/0xb0 [ 42.405806] skb_release_data+0x30e/0x3a0 [ 42.406198] skb_release_all+0x4a/0x60 [ 42.406563] consume_skb+0x113/0x2e0 [ 42.406910] skb_free_datagram+0x1a/0xe0 [ 42.407288] netlink_recvmsg+0x60d/0xe40 [ 42.407667] sock_recvmsg+0xd7/0x110 [ 42.408022] ___sys_recvmsg+0x25c/0x580 [ 42.408395] __sys_recvmsg+0xd6/0x190 [ 42.408753] SyS_recvmsg+0x2d/0x50 [ 42.409086] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 42.409513] [ 42.409665] The buggy address belongs to the object at ffff88000969e780 [ 42.409665] which belongs to the cache kmalloc-512 of size 512 [ 42.410846] The buggy address is located 24 bytes inside of [ 42.410846] 512-byte region [ffff88000969e780, ffff88000969e980) [ 42.411941] The buggy address belongs to the page: [ 42.412405] page:ffffea000025a780 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 42.413298] flags: 0x100000000008100(slab|head) [ 42.413729] raw: 0100000000008100 0000000000000000 0000000000000000 00000001800c000c [ 42.414387] raw: ffffea00002a9500 0000000900000007 ffff88000c401280 0000000000000000 [ 42.415074] page dumped because: kasan: bad access detected [ 42.415604] [ 42.415757] Memory state around the buggy address: [ 42.416222] ffff88000969e880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 42.416904] ffff88000969e900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 42.417591] >ffff88000969e980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 42.418273] ^ [ 42.418588] ffff88000969ea00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.419273] ffff88000969ea80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 42.419882] ================================================================== Reported-by: Andrey Konovalov Signed-off-by: Craig Gallek Signed-off-by: David S. Miller

net/tunnel: set inner protocol in network gro hooks

2017-03-09T21:19:52+00:00

The gso code of several tunnels type (gre and udp tunnels) takes for granted that the skb->inner_protocol is properly initialized and drops the packet elsewhere. On the forwarding path no one is initializing such field, so gro encapsulated packets are dropped on forward. Since commit 38720352412a ("gre: Use inner_proto to obtain inner header protocol"), this can be reproduced when the encapsulated packets use gre as the tunneling protocol. The issue happens also with vxlan and geneve tunnels since commit 8bce6d7d0d1e ("udp: Generalize skb_udp_segment"), if the forwarding host's ingress nic has h/w offload for such tunnel and a vxlan/geneve device is configured on top of it, regardless of the configured peer address and vni. To address the issue, this change initialize the inner_protocol field for encapsulated packets in both ipv4 and ipv6 gro complete callbacks. Fixes: 38720352412a ("gre: Use inner_proto to obtain inner header protocol") Fixes: 8bce6d7d0d1e ("udp: Generalize skb_udp_segment") Signed-off-by: Paolo Abeni Acked-by: Alexander Duyck Signed-off-by: David S. Miller

net: Add a skb_gro_flush_final helper.

2017-02-15T08:39:39+00:00

Add a skb_gro_flush_final helper to prepare for consuming skbs in call_gro_receive. We will extend this helper to not touch the skb if the skb is consumed by a gro callback with a followup patch. We need this to handle the upcomming IPsec ESP callbacks as they reinject the skb to the napi_gro_receive asynchronous. The handler is used in all gro_receive functions that can call the ESP gro handlers. Signed-off-by: Steffen Klassert

gro: Disable frag0 optimization on IPv6 ext headers

2017-01-11T02:30:33+00:00

The GRO fast path caches the frag0 address. This address becomes invalid if frag0 is modified by pskb_may_pull or its variants. So whenever that happens we must disable the frag0 optimization. This is usually done through the combination of gro_header_hard and gro_header_slow, however, the IPv6 extension header path did the pulling directly and would continue to use the GRO fast path incorrectly. This patch fixes it by disabling the fast path when we enter the IPv6 extension header path. Fixes: 78a478d0efd9 ("gro: Inline skb_gro_header and cache frag0 virtual address") Reported-by: Slava Shwartsman Signed-off-by: Herbert Xu Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ip6_offload: check segs for NULL in ipv6_gso_segment.

2016-12-02T18:34:58+00:00

segs needs to be checked for being NULL in ipv6_gso_segment() before calling skb_shinfo(segs), otherwise kernel can run into a NULL-pointer dereference: [ 97.811262] BUG: unable to handle kernel NULL pointer dereference at 00000000000000cc [ 97.819112] IP: [] ipv6_gso_segment+0x119/0x2f0 [ 97.825214] PGD 0 [ 97.827047] [ 97.828540] Oops: 0000 [#1] SMP [ 97.831678] Modules linked in: vhost_net vhost macvtap macvlan nfsv3 rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter bridge stp llc snd_hda_codec_realtek snd_hda_codec_hdmi snd_hda_codec_generic snd_hda_intel snd_hda_codec edac_mce_amd snd_hda_core edac_core snd_hwdep kvm_amd snd_seq kvm snd_seq_device snd_pcm irqbypass snd_timer ppdev parport_serial snd parport_pc k10temp pcspkr soundcore parport sp5100_tco shpchp sg wmi i2c_piix4 acpi_cpufreq nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sr_mod cdrom sd_mod ata_generic pata_acpi amdkfd amd_iommu_v2 radeon broadcom bcm_phy_lib i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm ahci serio_raw tg3 firewire_ohci libahci pata_atiixp drm ptp libata firewire_core pps_core i2c_core crc_itu_t fjes dm_mirror dm_region_hash dm_log dm_mod [ 97.927721] CPU: 1 PID: 3504 Comm: vhost-3495 Not tainted 4.9.0-7.el7.test.x86_64 #1 [ 97.935457] Hardware name: AMD Snook/Snook, BIOS ESK0726A 07/26/2010 [ 97.941806] task: ffff880129a1c080 task.stack: ffffc90001bcc000 [ 97.947720] RIP: 0010:[] [] ipv6_gso_segment+0x119/0x2f0 [ 97.956251] RSP: 0018:ffff88012fc43a10 EFLAGS: 00010207 [ 97.961557] RAX: 0000000000000000 RBX: ffff8801292c8700 RCX: 0000000000000594 [ 97.968687] RDX: 0000000000000593 RSI: ffff880129a846c0 RDI: 0000000000240000 [ 97.975814] RBP: ffff88012fc43a68 R08: ffff880129a8404e R09: 0000000000000000 [ 97.982942] R10: 0000000000000000 R11: ffff880129a84076 R12: 00000020002949b3 [ 97.990070] R13: ffff88012a580000 R14: 0000000000000000 R15: ffff88012a580000 [ 97.997198] FS: 0000000000000000(0000) GS:ffff88012fc40000(0000) knlGS:0000000000000000 [ 98.005280] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 98.011021] CR2: 00000000000000cc CR3: 0000000126c5d000 CR4: 00000000000006e0 [ 98.018149] Stack: [ 98.020157] 00000000ffffffff ffff88012fc43ac8 ffffffffa017ad0a 000000000000000e [ 98.027584] 0000001300000000 0000000077d59998 ffff8801292c8700 00000020002949b3 [ 98.035010] ffff88012a580000 0000000000000000 ffff88012a580000 ffff88012fc43a98 [ 98.042437] Call Trace: [ 98.044879] [ 98.046803] [] ? tg3_start_xmit+0x84a/0xd60 [tg3] [ 98.053156] [] skb_mac_gso_segment+0xb0/0x130 [ 98.059158] [] __skb_gso_segment+0x73/0x110 [ 98.064985] [] validate_xmit_skb+0x12d/0x2b0 [ 98.070899] [] validate_xmit_skb_list+0x42/0x70 [ 98.077073] [] sch_direct_xmit+0xd0/0x1b0 [ 98.082726] [] __dev_queue_xmit+0x486/0x690 [ 98.088554] [] ? cpumask_next_and+0x35/0x50 [ 98.094380] [] dev_queue_xmit+0x10/0x20 [ 98.099863] [] br_dev_queue_push_xmit+0xa7/0x170 [bridge] [ 98.106907] [] br_forward_finish+0x41/0xc0 [bridge] [ 98.113430] [] ? nf_iterate+0x52/0x60 [ 98.118735] [] ? nf_hook_slow+0x6b/0xc0 [ 98.124216] [] __br_forward+0x14c/0x1e0 [bridge] [ 98.130480] [] ? br_dev_queue_push_xmit+0x170/0x170 [bridge] [ 98.137785] [] br_forward+0x9d/0xb0 [bridge] [ 98.143701] [] br_handle_frame_finish+0x267/0x560 [bridge] [ 98.150834] [] br_handle_frame+0x174/0x2f0 [bridge] [ 98.157355] [] ? sched_clock+0x9/0x10 [ 98.162662] [] ? sched_clock_cpu+0x72/0xa0 [ 98.168403] [] __netif_receive_skb_core+0x1e5/0xa20 [ 98.174926] [] ? timerqueue_add+0x59/0xb0 [ 98.180580] [] __netif_receive_skb+0x18/0x60 [ 98.186494] [] process_backlog+0x95/0x140 [ 98.192145] [] net_rx_action+0x16d/0x380 [ 98.197713] [] __do_softirq+0xd1/0x283 [ 98.203106] [] do_softirq_own_stack+0x1c/0x30 [ 98.209107] [ 98.211029] [] do_softirq+0x50/0x60 [ 98.216166] [] netif_rx_ni+0x33/0x80 [ 98.221386] [] tun_get_user+0x487/0x7f0 [tun] [ 98.227388] [] tun_sendmsg+0x4b/0x60 [tun] [ 98.233129] [] handle_tx+0x282/0x540 [vhost_net] [ 98.239392] [] handle_tx_kick+0x15/0x20 [vhost_net] [ 98.245916] [] vhost_worker+0x9e/0xf0 [vhost] [ 98.251919] [] ? vhost_umem_alloc+0x40/0x40 [vhost] [ 98.258440] [] ? do_syscall_64+0x67/0x180 [ 98.264094] [] kthread+0xd9/0xf0 [ 98.268965] [] ? kthread_park+0x60/0x60 [ 98.274444] [] ret_from_fork+0x25/0x30 [ 98.279836] Code: 8b 93 d8 00 00 00 48 2b 93 d0 00 00 00 4c 89 e6 48 89 df 66 89 93 c2 00 00 00 ff 10 48 3d 00 f0 ff ff 49 89 c2 0f 87 52 01 00 00 <41> 8b 92 cc 00 00 00 48 8b 80 d0 00 00 00 44 0f b7 74 10 06 66 [ 98.299425] RIP [] ipv6_gso_segment+0x119/0x2f0 [ 98.305612] RSP [ 98.309094] CR2: 00000000000000cc [ 98.312406] ---[ end trace 726a2c7a2d2d78d0 ]--- Signed-off-by: Artem Savkov Acked-by: Eric Dumazet Signed-off-by: David S. Miller

net: add recursion limit to GRO

2016-10-20T18:32:22+00:00

Currently, GRO can do unlimited recursion through the gro_receive handlers. This was fixed for tunneling protocols by limiting tunnel GRO to one level with encap_mark, but both VLAN and TEB still have this problem. Thus, the kernel is vulnerable to a stack overflow, if we receive a packet composed entirely of VLAN headers. This patch adds a recursion counter to the GRO layer to prevent stack overflow. When a gro_receive function hits the recursion limit, GRO is aborted for this skb and it is processed normally. This recursion counter is put in the GRO CB, but could be turned into a percpu counter if we run out of space in the CB. Thanks to Vladimír Beneš for the initial bug report. Fixes: CVE-2016-7039 Fixes: 9b174d88c257 ("net: Add Transparent Ethernet Bridging GRO support.") Fixes: 66e5133f19e9 ("vlan: Add GRO support for non hardware accelerated vlan") Signed-off-by: Sabrina Dubroca Reviewed-by: Jiri Benc Acked-by: Hannes Frederic Sowa Acked-by: Tom Herbert Signed-off-by: David S. Miller

gso: Support partial splitting at the frag_list pointer

2016-09-20T00:59:34+00:00

Since commit 8a29111c7 ("net: gro: allow to build full sized skb") gro may build buffers with a frag_list. This can hurt forwarding because most NICs can't offload such packets, they need to be segmented in software. This patch splits buffers with a frag_list at the frag_list pointer into buffers that can be TSO offloaded. Signed-off-by: Steffen Klassert Acked-by: Alexander Duyck Signed-off-by: David S. Miller