linux-stable.git/net/ipv6, branch v4.9.331 Linux kernel stable tree inet: fully convert sk->sk_rx_dst to RCU rules 2022-10-26T11:15:48+00:00 Eric Dumazet edumazet@google.com 2021-12-20T14:33:30+00:00 68c34ce11ef23328692aa35fa6aaafdd75913100 commit 8f905c0e7354ef261360fb7535ea079b1082c105 upstream. syzbot reported various issues around early demux, one being included in this changelog [1] sk->sk_rx_dst is using RCU protection without clearly documenting it. And following sequences in tcp_v4_do_rcv()/tcp_v6_do_rcv() are not following standard RCU rules. [a] dst_release(dst); [b] sk->sk_rx_dst = NULL; They look wrong because a delete operation of RCU protected pointer is supposed to clear the pointer before the call_rcu()/synchronize_rcu() guarding actual memory freeing. In some cases indeed, dst could be freed before [b] is done. We could cheat by clearing sk_rx_dst before calling dst_release(), but this seems the right time to stick to standard RCU annotations and debugging facilities. [1] BUG: KASAN: use-after-free in dst_check include/net/dst.h:470 [inline] BUG: KASAN: use-after-free in tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792 Read of size 2 at addr ffff88807f1cb73a by task syz-executor.5/9204 CPU: 0 PID: 9204 Comm: syz-executor.5 Not tainted 5.16.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247 __kasan_report mm/kasan/report.c:433 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:450 dst_check include/net/dst.h:470 [inline] tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792 ip_rcv_finish_core.constprop.0+0x15de/0x1e80 net/ipv4/ip_input.c:340 ip_list_rcv_finish.constprop.0+0x1b2/0x6e0 net/ipv4/ip_input.c:583 ip_sublist_rcv net/ipv4/ip_input.c:609 [inline] ip_list_rcv+0x34e/0x490 net/ipv4/ip_input.c:644 __netif_receive_skb_list_ptype net/core/dev.c:5508 [inline] __netif_receive_skb_list_core+0x549/0x8e0 net/core/dev.c:5556 __netif_receive_skb_list net/core/dev.c:5608 [inline] netif_receive_skb_list_internal+0x75e/0xd80 net/core/dev.c:5699 gro_normal_list net/core/dev.c:5853 [inline] gro_normal_list net/core/dev.c:5849 [inline] napi_complete_done+0x1f1/0x880 net/core/dev.c:6590 virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline] virtnet_poll+0xca2/0x11b0 drivers/net/virtio_net.c:1557 __napi_poll+0xaf/0x440 net/core/dev.c:7023 napi_poll net/core/dev.c:7090 [inline] net_rx_action+0x801/0xb40 net/core/dev.c:7177 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 common_interrupt+0x52/0xc0 arch/x86/kernel/irq.c:240 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629 RIP: 0033:0x7f5e972bfd57 Code: 39 d1 73 14 0f 1f 80 00 00 00 00 48 8b 50 f8 48 83 e8 08 48 39 ca 77 f3 48 39 c3 73 3e 48 89 13 48 8b 50 f8 48 89 38 49 8b 0e <48> 8b 3e 48 83 c3 08 48 83 c6 08 eb bc 48 39 d1 72 9e 48 39 d0 73 RSP: 002b:00007fff8a413210 EFLAGS: 00000283 RAX: 00007f5e97108990 RBX: 00007f5e97108338 RCX: ffffffff81d3aa45 RDX: ffffffff81d3aa45 RSI: 00007f5e97108340 RDI: ffffffff81d3aa45 RBP: 00007f5e97107eb8 R08: 00007f5e97108d88 R09: 0000000093c2e8d9 R10: 0000000000000000 R11: 0000000000000000 R12: 00007f5e97107eb0 R13: 00007f5e97108338 R14: 00007f5e97107ea8 R15: 0000000000000019 </TASK> Allocated by task 13: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:259 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc_node mm/slub.c:3234 [inline] slab_alloc mm/slub.c:3242 [inline] kmem_cache_alloc+0x202/0x3a0 mm/slub.c:3247 dst_alloc+0x146/0x1f0 net/core/dst.c:92 rt_dst_alloc+0x73/0x430 net/ipv4/route.c:1613 ip_route_input_slow+0x1817/0x3a20 net/ipv4/route.c:2340 ip_route_input_rcu net/ipv4/route.c:2470 [inline] ip_route_input_noref+0x116/0x2a0 net/ipv4/route.c:2415 ip_rcv_finish_core.constprop.0+0x288/0x1e80 net/ipv4/ip_input.c:354 ip_list_rcv_finish.constprop.0+0x1b2/0x6e0 net/ipv4/ip_input.c:583 ip_sublist_rcv net/ipv4/ip_input.c:609 [inline] ip_list_rcv+0x34e/0x490 net/ipv4/ip_input.c:644 __netif_receive_skb_list_ptype net/core/dev.c:5508 [inline] __netif_receive_skb_list_core+0x549/0x8e0 net/core/dev.c:5556 __netif_receive_skb_list net/core/dev.c:5608 [inline] netif_receive_skb_list_internal+0x75e/0xd80 net/core/dev.c:5699 gro_normal_list net/core/dev.c:5853 [inline] gro_normal_list net/core/dev.c:5849 [inline] napi_complete_done+0x1f1/0x880 net/core/dev.c:6590 virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline] virtnet_poll+0xca2/0x11b0 drivers/net/virtio_net.c:1557 __napi_poll+0xaf/0x440 net/core/dev.c:7023 napi_poll net/core/dev.c:7090 [inline] net_rx_action+0x801/0xb40 net/core/dev.c:7177 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 Freed by task 13: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1749 slab_free mm/slub.c:3513 [inline] kmem_cache_free+0xbd/0x5d0 mm/slub.c:3530 dst_destroy+0x2d6/0x3f0 net/core/dst.c:127 rcu_do_batch kernel/rcu/tree.c:2506 [inline] rcu_core+0x7ab/0x1470 kernel/rcu/tree.c:2741 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 Last potentially related work creation: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 __kasan_record_aux_stack+0xf5/0x120 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:2985 [inline] call_rcu+0xb1/0x740 kernel/rcu/tree.c:3065 dst_release net/core/dst.c:177 [inline] dst_release+0x79/0xe0 net/core/dst.c:167 tcp_v4_do_rcv+0x612/0x8d0 net/ipv4/tcp_ipv4.c:1712 sk_backlog_rcv include/net/sock.h:1030 [inline] __release_sock+0x134/0x3b0 net/core/sock.c:2768 release_sock+0x54/0x1b0 net/core/sock.c:3300 tcp_sendmsg+0x36/0x40 net/ipv4/tcp.c:1441 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 sock_write_iter+0x289/0x3c0 net/socket.c:1057 call_write_iter include/linux/fs.h:2162 [inline] new_sync_write+0x429/0x660 fs/read_write.c:503 vfs_write+0x7cd/0xae0 fs/read_write.c:590 ksys_write+0x1ee/0x250 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff88807f1cb700 which belongs to the cache ip_dst_cache of size 176 The buggy address is located 58 bytes inside of 176-byte region [ffff88807f1cb700, ffff88807f1cb7b0) The buggy address belongs to the page: page:ffffea0001fc72c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7f1cb flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 dead000000000100 dead000000000122 ffff8881413bb780 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 5, ts 108466983062, free_ts 108048976062 prep_new_page mm/page_alloc.c:2418 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369 alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191 alloc_slab_page mm/slub.c:1793 [inline] allocate_slab mm/slub.c:1930 [inline] new_slab+0x32d/0x4a0 mm/slub.c:1993 ___slab_alloc+0x918/0xfe0 mm/slub.c:3022 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109 slab_alloc_node mm/slub.c:3200 [inline] slab_alloc mm/slub.c:3242 [inline] kmem_cache_alloc+0x35c/0x3a0 mm/slub.c:3247 dst_alloc+0x146/0x1f0 net/core/dst.c:92 rt_dst_alloc+0x73/0x430 net/ipv4/route.c:1613 __mkroute_output net/ipv4/route.c:2564 [inline] ip_route_output_key_hash_rcu+0x921/0x2d00 net/ipv4/route.c:2791 ip_route_output_key_hash+0x18b/0x300 net/ipv4/route.c:2619 __ip_route_output_key include/net/route.h:126 [inline] ip_route_output_flow+0x23/0x150 net/ipv4/route.c:2850 ip_route_output_key include/net/route.h:142 [inline] geneve_get_v4_rt+0x3a6/0x830 drivers/net/geneve.c:809 geneve_xmit_skb drivers/net/geneve.c:899 [inline] geneve_xmit+0xc4a/0x3540 drivers/net/geneve.c:1082 __netdev_start_xmit include/linux/netdevice.h:4994 [inline] netdev_start_xmit include/linux/netdevice.h:5008 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3606 __dev_queue_xmit+0x299a/0x3650 net/core/dev.c:4229 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1338 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1389 free_unref_page_prepare mm/page_alloc.c:3309 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3388 qlink_free mm/kasan/quarantine.c:146 [inline] qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:259 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc_node mm/slub.c:3234 [inline] kmem_cache_alloc_node+0x255/0x3f0 mm/slub.c:3270 __alloc_skb+0x215/0x340 net/core/skbuff.c:414 alloc_skb include/linux/skbuff.h:1126 [inline] alloc_skb_with_frags+0x93/0x620 net/core/skbuff.c:6078 sock_alloc_send_pskb+0x783/0x910 net/core/sock.c:2575 mld_newpack+0x1df/0x770 net/ipv6/mcast.c:1754 add_grhead+0x265/0x330 net/ipv6/mcast.c:1857 add_grec+0x1053/0x14e0 net/ipv6/mcast.c:1995 mld_send_initial_cr.part.0+0xf6/0x230 net/ipv6/mcast.c:2242 mld_send_initial_cr net/ipv6/mcast.c:1232 [inline] mld_dad_work+0x1d3/0x690 net/ipv6/mcast.c:2268 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 Memory state around the buggy address: ffff88807f1cb600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807f1cb680: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc >ffff88807f1cb700: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807f1cb780: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc ffff88807f1cb800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 41063e9dd119 ("ipv4: Early TCP socket demux.") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20211220143330.680945-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> [cmllamas: backported to 4.9; dropped irrelevant hunks in ipv6/udp.c; added rcu_access_pointer(sk->sk_rx_dst) in tcp_prequeue().] Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8f905c0e7354ef261360fb7535ea079b1082c105 upstream.

syzbot reported various issues around early demux,
one being included in this changelog [1]

sk->sk_rx_dst is using RCU protection without clearly
documenting it.

And following sequences in tcp_v4_do_rcv()/tcp_v6_do_rcv()
are not following standard RCU rules.

[a]    dst_release(dst);
[b]    sk->sk_rx_dst = NULL;

They look wrong because a delete operation of RCU protected
pointer is supposed to clear the pointer before
the call_rcu()/synchronize_rcu() guarding actual memory freeing.

In some cases indeed, dst could be freed before [b] is done.

We could cheat by clearing sk_rx_dst before calling
dst_release(), but this seems the right time to stick
to standard RCU annotations and debugging facilities.

[1]
BUG: KASAN: use-after-free in dst_check include/net/dst.h:470 [inline]
BUG: KASAN: use-after-free in tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792
Read of size 2 at addr ffff88807f1cb73a by task syz-executor.5/9204

CPU: 0 PID: 9204 Comm: syz-executor.5 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247
 __kasan_report mm/kasan/report.c:433 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:450
 dst_check include/net/dst.h:470 [inline]
 tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792
 ip_rcv_finish_core.constprop.0+0x15de/0x1e80 net/ipv4/ip_input.c:340
 ip_list_rcv_finish.constprop.0+0x1b2/0x6e0 net/ipv4/ip_input.c:583
 ip_sublist_rcv net/ipv4/ip_input.c:609 [inline]
 ip_list_rcv+0x34e/0x490 net/ipv4/ip_input.c:644
 __netif_receive_skb_list_ptype net/core/dev.c:5508 [inline]
 __netif_receive_skb_list_core+0x549/0x8e0 net/core/dev.c:5556
 __netif_receive_skb_list net/core/dev.c:5608 [inline]
 netif_receive_skb_list_internal+0x75e/0xd80 net/core/dev.c:5699
 gro_normal_list net/core/dev.c:5853 [inline]
 gro_normal_list net/core/dev.c:5849 [inline]
 napi_complete_done+0x1f1/0x880 net/core/dev.c:6590
 virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline]
 virtnet_poll+0xca2/0x11b0 drivers/net/virtio_net.c:1557
 __napi_poll+0xaf/0x440 net/core/dev.c:7023
 napi_poll net/core/dev.c:7090 [inline]
 net_rx_action+0x801/0xb40 net/core/dev.c:7177
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
 common_interrupt+0x52/0xc0 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629
RIP: 0033:0x7f5e972bfd57
Code: 39 d1 73 14 0f 1f 80 00 00 00 00 48 8b 50 f8 48 83 e8 08 48 39 ca 77 f3 48 39 c3 73 3e 48 89 13 48 8b 50 f8 48 89 38 49 8b 0e <48> 8b 3e 48 83 c3 08 48 83 c6 08 eb bc 48 39 d1 72 9e 48 39 d0 73
RSP: 002b:00007fff8a413210 EFLAGS: 00000283
RAX: 00007f5e97108990 RBX: 00007f5e97108338 RCX: ffffffff81d3aa45
RDX: ffffffff81d3aa45 RSI: 00007f5e97108340 RDI: ffffffff81d3aa45
RBP: 00007f5e97107eb8 R08: 00007f5e97108d88 R09: 0000000093c2e8d9
R10: 0000000000000000 R11: 0000000000000000 R12: 00007f5e97107eb0
R13: 00007f5e97108338 R14: 00007f5e97107ea8 R15: 0000000000000019
 </TASK>

Allocated by task 13:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:259 [inline]
 slab_post_alloc_hook mm/slab.h:519 [inline]
 slab_alloc_node mm/slub.c:3234 [inline]
 slab_alloc mm/slub.c:3242 [inline]
 kmem_cache_alloc+0x202/0x3a0 mm/slub.c:3247
 dst_alloc+0x146/0x1f0 net/core/dst.c:92
 rt_dst_alloc+0x73/0x430 net/ipv4/route.c:1613
 ip_route_input_slow+0x1817/0x3a20 net/ipv4/route.c:2340
 ip_route_input_rcu net/ipv4/route.c:2470 [inline]
 ip_route_input_noref+0x116/0x2a0 net/ipv4/route.c:2415
 ip_rcv_finish_core.constprop.0+0x288/0x1e80 net/ipv4/ip_input.c:354
 ip_list_rcv_finish.constprop.0+0x1b2/0x6e0 net/ipv4/ip_input.c:583
 ip_sublist_rcv net/ipv4/ip_input.c:609 [inline]
 ip_list_rcv+0x34e/0x490 net/ipv4/ip_input.c:644
 __netif_receive_skb_list_ptype net/core/dev.c:5508 [inline]
 __netif_receive_skb_list_core+0x549/0x8e0 net/core/dev.c:5556
 __netif_receive_skb_list net/core/dev.c:5608 [inline]
 netif_receive_skb_list_internal+0x75e/0xd80 net/core/dev.c:5699
 gro_normal_list net/core/dev.c:5853 [inline]
 gro_normal_list net/core/dev.c:5849 [inline]
 napi_complete_done+0x1f1/0x880 net/core/dev.c:6590
 virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline]
 virtnet_poll+0xca2/0x11b0 drivers/net/virtio_net.c:1557
 __napi_poll+0xaf/0x440 net/core/dev.c:7023
 napi_poll net/core/dev.c:7090 [inline]
 net_rx_action+0x801/0xb40 net/core/dev.c:7177
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558

Freed by task 13:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free mm/kasan/common.c:328 [inline]
 __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:1723 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1749
 slab_free mm/slub.c:3513 [inline]
 kmem_cache_free+0xbd/0x5d0 mm/slub.c:3530
 dst_destroy+0x2d6/0x3f0 net/core/dst.c:127
 rcu_do_batch kernel/rcu/tree.c:2506 [inline]
 rcu_core+0x7ab/0x1470 kernel/rcu/tree.c:2741
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558

Last potentially related work creation:
 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xf5/0x120 mm/kasan/generic.c:348
 __call_rcu kernel/rcu/tree.c:2985 [inline]
 call_rcu+0xb1/0x740 kernel/rcu/tree.c:3065
 dst_release net/core/dst.c:177 [inline]
 dst_release+0x79/0xe0 net/core/dst.c:167
 tcp_v4_do_rcv+0x612/0x8d0 net/ipv4/tcp_ipv4.c:1712
 sk_backlog_rcv include/net/sock.h:1030 [inline]
 __release_sock+0x134/0x3b0 net/core/sock.c:2768
 release_sock+0x54/0x1b0 net/core/sock.c:3300
 tcp_sendmsg+0x36/0x40 net/ipv4/tcp.c:1441
 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:724
 sock_write_iter+0x289/0x3c0 net/socket.c:1057
 call_write_iter include/linux/fs.h:2162 [inline]
 new_sync_write+0x429/0x660 fs/read_write.c:503
 vfs_write+0x7cd/0xae0 fs/read_write.c:590
 ksys_write+0x1ee/0x250 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff88807f1cb700
 which belongs to the cache ip_dst_cache of size 176
The buggy address is located 58 bytes inside of
 176-byte region [ffff88807f1cb700, ffff88807f1cb7b0)
The buggy address belongs to the page:
page:ffffea0001fc72c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7f1cb
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 dead000000000100 dead000000000122 ffff8881413bb780
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 5, ts 108466983062, free_ts 108048976062
 prep_new_page mm/page_alloc.c:2418 [inline]
 get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369
 alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191
 alloc_slab_page mm/slub.c:1793 [inline]
 allocate_slab mm/slub.c:1930 [inline]
 new_slab+0x32d/0x4a0 mm/slub.c:1993
 ___slab_alloc+0x918/0xfe0 mm/slub.c:3022
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109
 slab_alloc_node mm/slub.c:3200 [inline]
 slab_alloc mm/slub.c:3242 [inline]
 kmem_cache_alloc+0x35c/0x3a0 mm/slub.c:3247
 dst_alloc+0x146/0x1f0 net/core/dst.c:92
 rt_dst_alloc+0x73/0x430 net/ipv4/route.c:1613
 __mkroute_output net/ipv4/route.c:2564 [inline]
 ip_route_output_key_hash_rcu+0x921/0x2d00 net/ipv4/route.c:2791
 ip_route_output_key_hash+0x18b/0x300 net/ipv4/route.c:2619
 __ip_route_output_key include/net/route.h:126 [inline]
 ip_route_output_flow+0x23/0x150 net/ipv4/route.c:2850
 ip_route_output_key include/net/route.h:142 [inline]
 geneve_get_v4_rt+0x3a6/0x830 drivers/net/geneve.c:809
 geneve_xmit_skb drivers/net/geneve.c:899 [inline]
 geneve_xmit+0xc4a/0x3540 drivers/net/geneve.c:1082
 __netdev_start_xmit include/linux/netdevice.h:4994 [inline]
 netdev_start_xmit include/linux/netdevice.h:5008 [inline]
 xmit_one net/core/dev.c:3590 [inline]
 dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3606
 __dev_queue_xmit+0x299a/0x3650 net/core/dev.c:4229
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1338 [inline]
 free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1389
 free_unref_page_prepare mm/page_alloc.c:3309 [inline]
 free_unref_page+0x19/0x690 mm/page_alloc.c:3388
 qlink_free mm/kasan/quarantine.c:146 [inline]
 qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165
 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272
 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:259 [inline]
 slab_post_alloc_hook mm/slab.h:519 [inline]
 slab_alloc_node mm/slub.c:3234 [inline]
 kmem_cache_alloc_node+0x255/0x3f0 mm/slub.c:3270
 __alloc_skb+0x215/0x340 net/core/skbuff.c:414
 alloc_skb include/linux/skbuff.h:1126 [inline]
 alloc_skb_with_frags+0x93/0x620 net/core/skbuff.c:6078
 sock_alloc_send_pskb+0x783/0x910 net/core/sock.c:2575
 mld_newpack+0x1df/0x770 net/ipv6/mcast.c:1754
 add_grhead+0x265/0x330 net/ipv6/mcast.c:1857
 add_grec+0x1053/0x14e0 net/ipv6/mcast.c:1995
 mld_send_initial_cr.part.0+0xf6/0x230 net/ipv6/mcast.c:2242
 mld_send_initial_cr net/ipv6/mcast.c:1232 [inline]
 mld_dad_work+0x1d3/0x690 net/ipv6/mcast.c:2268
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445

Memory state around the buggy address:
 ffff88807f1cb600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807f1cb680: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
>ffff88807f1cb700: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff88807f1cb780: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
 ffff88807f1cb800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Fixes: 41063e9dd119 ("ipv4: Early TCP socket demux.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20211220143330.680945-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[cmllamas: backported to 4.9; dropped irrelevant hunks in ipv6/udp.c;
 added rcu_access_pointer(sk->sk_rx_dst) in tcp_prequeue().]
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: ping6: Fix memleak in ipv6_renew_options(). 2022-08-25T09:09:20+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2022-07-28T01:22:20+00:00 dd3fdf3b35e747593ed7ec5e59dea9b6df03cf62 commit e27326009a3d247b831eda38878c777f6f4eb3d1 upstream. When we close ping6 sockets, some resources are left unfreed because pingv6_prot is missing sk->sk_prot->destroy(). As reported by syzbot [0], just three syscalls leak 96 bytes and easily cause OOM. struct ipv6_sr_hdr *hdr; char data[24] = {0}; int fd; hdr = (struct ipv6_sr_hdr *)data; hdr->hdrlen = 2; hdr->type = IPV6_SRCRT_TYPE_4; fd = socket(AF_INET6, SOCK_DGRAM, NEXTHDR_ICMP); setsockopt(fd, IPPROTO_IPV6, IPV6_RTHDR, data, 24); close(fd); To fix memory leaks, let's add a destroy function. Note the socket() syscall checks if the GID is within the range of net.ipv4.ping_group_range. The default value is [1, 0] so that no GID meets the condition (1 <= GID <= 0). Thus, the local DoS does not succeed until we change the default value. However, at least Ubuntu/Fedora/RHEL loosen it. $ cat /usr/lib/sysctl.d/50-default.conf ... -net.ipv4.ping_group_range = 0 2147483647 Also, there could be another path reported with these options, and some of them require CAP_NET_RAW. setsockopt IPV6_ADDRFORM (inet6_sk(sk)->pktoptions) IPV6_RECVPATHMTU (inet6_sk(sk)->rxpmtu) IPV6_HOPOPTS (inet6_sk(sk)->opt) IPV6_RTHDRDSTOPTS (inet6_sk(sk)->opt) IPV6_RTHDR (inet6_sk(sk)->opt) IPV6_DSTOPTS (inet6_sk(sk)->opt) IPV6_2292PKTOPTIONS (inet6_sk(sk)->opt) getsockopt IPV6_FLOWLABEL_MGR (inet6_sk(sk)->ipv6_fl_list) For the record, I left a different splat with syzbot's one. unreferenced object 0xffff888006270c60 (size 96): comm "repro2", pid 231, jiffies 4294696626 (age 13.118s) hex dump (first 32 bytes): 01 00 00 00 44 00 00 00 00 00 00 00 00 00 00 00 ....D........... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000f6bc7ea9>] sock_kmalloc (net/core/sock.c:2564 net/core/sock.c:2554) [<000000006d699550>] do_ipv6_setsockopt.constprop.0 (net/ipv6/ipv6_sockglue.c:715) [<00000000c3c3b1f5>] ipv6_setsockopt (net/ipv6/ipv6_sockglue.c:1024) [<000000007096a025>] __sys_setsockopt (net/socket.c:2254) [<000000003a8ff47b>] __x64_sys_setsockopt (net/socket.c:2265 net/socket.c:2262 net/socket.c:2262) [<000000007c409dcb>] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) [<00000000e939c4a9>] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) [0]: https://syzkaller.appspot.com/bug?extid=a8430774139ec3ab7176 Fixes: 6d0bfe226116 ("net: ipv6: Add IPv6 support to the ping socket.") Reported-by: syzbot+a8430774139ec3ab7176@syzkaller.appspotmail.com Reported-by: Ayushman Dutta <ayudutta@amazon.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20220728012220.46918-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e27326009a3d247b831eda38878c777f6f4eb3d1 upstream.

When we close ping6 sockets, some resources are left unfreed because
pingv6_prot is missing sk->sk_prot->destroy().  As reported by
syzbot [0], just three syscalls leak 96 bytes and easily cause OOM.

    struct ipv6_sr_hdr *hdr;
    char data[24] = {0};
    int fd;

    hdr = (struct ipv6_sr_hdr *)data;
    hdr->hdrlen = 2;
    hdr->type = IPV6_SRCRT_TYPE_4;

    fd = socket(AF_INET6, SOCK_DGRAM, NEXTHDR_ICMP);
    setsockopt(fd, IPPROTO_IPV6, IPV6_RTHDR, data, 24);
    close(fd);

To fix memory leaks, let's add a destroy function.

Note the socket() syscall checks if the GID is within the range of
net.ipv4.ping_group_range.  The default value is [1, 0] so that no
GID meets the condition (1 <= GID <= 0).  Thus, the local DoS does
not succeed until we change the default value.  However, at least
Ubuntu/Fedora/RHEL loosen it.

    $ cat /usr/lib/sysctl.d/50-default.conf
    ...
    -net.ipv4.ping_group_range = 0 2147483647

Also, there could be another path reported with these options, and
some of them require CAP_NET_RAW.

  setsockopt
      IPV6_ADDRFORM (inet6_sk(sk)->pktoptions)
      IPV6_RECVPATHMTU (inet6_sk(sk)->rxpmtu)
      IPV6_HOPOPTS (inet6_sk(sk)->opt)
      IPV6_RTHDRDSTOPTS (inet6_sk(sk)->opt)
      IPV6_RTHDR (inet6_sk(sk)->opt)
      IPV6_DSTOPTS (inet6_sk(sk)->opt)
      IPV6_2292PKTOPTIONS (inet6_sk(sk)->opt)

  getsockopt
      IPV6_FLOWLABEL_MGR (inet6_sk(sk)->ipv6_fl_list)

For the record, I left a different splat with syzbot's one.

  unreferenced object 0xffff888006270c60 (size 96):
    comm "repro2", pid 231, jiffies 4294696626 (age 13.118s)
    hex dump (first 32 bytes):
      01 00 00 00 44 00 00 00 00 00 00 00 00 00 00 00  ....D...........
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    backtrace:
      [<00000000f6bc7ea9>] sock_kmalloc (net/core/sock.c:2564 net/core/sock.c:2554)
      [<000000006d699550>] do_ipv6_setsockopt.constprop.0 (net/ipv6/ipv6_sockglue.c:715)
      [<00000000c3c3b1f5>] ipv6_setsockopt (net/ipv6/ipv6_sockglue.c:1024)
      [<000000007096a025>] __sys_setsockopt (net/socket.c:2254)
      [<000000003a8ff47b>] __x64_sys_setsockopt (net/socket.c:2265 net/socket.c:2262 net/socket.c:2262)
      [<000000007c409dcb>] do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
      [<00000000e939c4a9>] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)

[0]: https://syzkaller.appspot.com/bug?extid=a8430774139ec3ab7176

Fixes: 6d0bfe226116 ("net: ipv6: Add IPv6 support to the ping socket.")
Reported-by: syzbot+a8430774139ec3ab7176@syzkaller.appspotmail.com
Reported-by: Ayushman Dutta <ayudutta@amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220728012220.46918-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6/sit: fix ipip6_tunnel_get_prl return value 2022-07-07T15:30:11+00:00 katrinzhou katrinzhou@tencent.com 2022-06-28T03:50:30+00:00 bb5584c25b7cef769690f64355a9941b822b4d30 commit adabdd8f6acabc0c3fdbba2e7f5a2edd9c5ef22d upstream. When kcalloc fails, ipip6_tunnel_get_prl() should return -ENOMEM. Move the position of label "out" to return correctly. Addresses-Coverity: ("Unused value") Fixes: 300aaeeaab5f ("[IPV6] SIT: Add SIOCGETPRL ioctl to get/dump PRL.") Signed-off-by: katrinzhou <katrinzhou@tencent.com> Reviewed-by: Eric Dumazet<edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20220628035030.1039171-1-zys.zljxml@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit adabdd8f6acabc0c3fdbba2e7f5a2edd9c5ef22d upstream.

When kcalloc fails, ipip6_tunnel_get_prl() should return -ENOMEM.
Move the position of label "out" to return correctly.

Addresses-Coverity: ("Unused value")
Fixes: 300aaeeaab5f ("[IPV6] SIT: Add SIOCGETPRL ioctl to get/dump PRL.")
Signed-off-by: katrinzhou <katrinzhou@tencent.com>
Reviewed-by: Eric Dumazet<edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220628035030.1039171-1-zys.zljxml@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sit: use min 2022-07-07T15:30:11+00:00 kernel test robot lkp@intel.com 2021-03-27T09:29:32+00:00 c74f0e0243cbdf0244ba56c64c2d72edb49f3631 commit 284fda1eff8a8b27d2cafd7dc8fb423d13720f21 upstream. Opportunity for min() Generated by: scripts/coccinelle/misc/minmax.cocci CC: Denis Efremov <efremov@linux.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: kernel test robot <lkp@intel.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 284fda1eff8a8b27d2cafd7dc8fb423d13720f21 upstream.

Opportunity for min()

Generated by: scripts/coccinelle/misc/minmax.cocci

CC: Denis Efremov <efremov@linux.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
secure_seq: use the 64 bits of the siphash for port offset calculation 2022-06-25T09:45:19+00:00 Willy Tarreau w@1wt.eu 2022-05-02T08:46:08+00:00 576696ed0dee677ec868960c39d96ae3b8c95a3f commit b2d057560b8107c633b39aabe517ff9d93f285e3 upstream. SipHash replaced MD5 in secure_ipv{4,6}_port_ephemeral() via commit 7cd23e5300c1 ("secure_seq: use SipHash in place of MD5"), but the output remained truncated to 32-bit only. In order to exploit more bits from the hash, let's make the functions return the full 64-bit of siphash_3u32(). We also make sure the port offset calculation in __inet_hash_connect() remains done on 32-bit to avoid the need for div_u64_rem() and an extra cost on 32-bit systems. Cc: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Moshe Kol <moshe.kol@mail.huji.ac.il> Cc: Yossi Gilad <yossi.gilad@mail.huji.ac.il> Cc: Amit Klein <aksecurity@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b2d057560b8107c633b39aabe517ff9d93f285e3 upstream.

SipHash replaced MD5 in secure_ipv{4,6}_port_ephemeral() via commit
7cd23e5300c1 ("secure_seq: use SipHash in place of MD5"), but the output
remained truncated to 32-bit only. In order to exploit more bits from the
hash, let's make the functions return the full 64-bit of siphash_3u32().
We also make sure the port offset calculation in __inet_hash_connect()
remains done on 32-bit to avoid the need for div_u64_rem() and an extra
cost on 32-bit systems.

Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Moshe Kol <moshe.kol@mail.huji.ac.il>
Cc: Yossi Gilad <yossi.gilad@mail.huji.ac.il>
Cc: Amit Klein <aksecurity@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: Don't send rs packets to the interface of ARPHRD_TUNNEL 2022-06-14T14:52:29+00:00 jianghaoran jianghaoran@kylinos.cn 2022-04-29T05:38:02+00:00 b0caa4967dd2d87023124b33f8998827f653872c [ Upstream commit b52e1cce31ca721e937d517411179f9196ee6135 ] ARPHRD_TUNNEL interface can't process rs packets and will generate TX errors ex: ip tunnel add ethn mode ipip local 192.168.1.1 remote 192.168.1.2 ifconfig ethn x.x.x.x ethn: flags=209<UP,POINTOPOINT,RUNNING,NOARP> mtu 1480 inet x.x.x.x netmask 255.255.255.255 destination x.x.x.x inet6 fe80::5efe:ac1e:3cdb prefixlen 64 scopeid 0x20<link> tunnel txqueuelen 1000 (IPIP Tunnel) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 3 dropped 0 overruns 0 carrier 0 collisions 0 Signed-off-by: jianghaoran <jianghaoran@kylinos.cn> Link: https://lore.kernel.org/r/20220429053802.246681-1-jianghaoran@kylinos.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b52e1cce31ca721e937d517411179f9196ee6135 ]

ARPHRD_TUNNEL interface can't process rs packets
and will generate TX errors

ex:
ip tunnel add ethn mode ipip local 192.168.1.1 remote 192.168.1.2
ifconfig ethn x.x.x.x

ethn: flags=209<UP,POINTOPOINT,RUNNING,NOARP>  mtu 1480
	inet x.x.x.x  netmask 255.255.255.255  destination x.x.x.x
	inet6 fe80::5efe:ac1e:3cdb  prefixlen 64  scopeid 0x20<link>
	tunnel   txqueuelen 1000  (IPIP Tunnel)
	RX packets 0  bytes 0 (0.0 B)
	RX errors 0  dropped 0  overruns 0  frame 0
	TX packets 0  bytes 0 (0.0 B)
	TX errors 3  dropped 0 overruns 0  carrier 0  collisions 0

Signed-off-by: jianghaoran <jianghaoran@kylinos.cn>
Link: https://lore.kernel.org/r/20220429053802.246681-1-jianghaoran@kylinos.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: ipv6: ensure we call ipv6_mc_down() at most once 2022-05-12T10:14:58+00:00 j.nixdorf@avm.de j.nixdorf@avm.de 2022-02-24T09:06:49+00:00 9a8736b2da28b24f01707f592ff059b9f90a058c commit 9995b408f17ff8c7f11bc725c8aa225ba3a63b1c upstream. There are two reasons for addrconf_notify() to be called with NETDEV_DOWN: either the network device is actually going down, or IPv6 was disabled on the interface. If either of them stays down while the other is toggled, we repeatedly call the code for NETDEV_DOWN, including ipv6_mc_down(), while never calling the corresponding ipv6_mc_up() in between. This will cause a new entry in idev->mc_tomb to be allocated for each multicast group the interface is subscribed to, which in turn leaks one struct ifmcaddr6 per nontrivial multicast group the interface is subscribed to. The following reproducer will leak at least $n objects: ip addr add ff2e::4242/32 dev eth0 autojoin sysctl -w net.ipv6.conf.eth0.disable_ipv6=1 for i in $(seq 1 $n); do ip link set up eth0; ip link set down eth0 done Joining groups with IPV6_ADD_MEMBERSHIP (unprivileged) or setting the sysctl net.ipv6.conf.eth0.forwarding to 1 (=> subscribing to ff02::2) can also be used to create a nontrivial idev->mc_list, which will the leak objects with the right up-down-sequence. Based on both sources for NETDEV_DOWN events the interface IPv6 state should be considered: - not ready if the network interface is not ready OR IPv6 is disabled for it - ready if the network interface is ready AND IPv6 is enabled for it The functions ipv6_mc_up() and ipv6_down() should only be run when this state changes. Implement this by remembering when the IPv6 state is ready, and only run ipv6_mc_down() if it actually changed from ready to not ready. The other direction (not ready -> ready) already works correctly, as: - the interface notification triggered codepath for NETDEV_UP / NETDEV_CHANGE returns early if ipv6 is disabled, and - the disable_ipv6=0 triggered codepath skips fully initializing the interface as long as addrconf_link_ready(dev) returns false - calling ipv6_mc_up() repeatedly does not leak anything Fixes: 3ce62a84d53c ("ipv6: exit early in addrconf_notify() if IPv6 is disabled") Signed-off-by: Johannes Nixdorf <j.nixdorf@avm.de> Signed-off-by: David S. Miller <davem@davemloft.net> [jnixdorf: context updated for bpo to v4.9/v4.14] Signed-off-by: Johannes Nixdorf <j.nixdorf@avm.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9995b408f17ff8c7f11bc725c8aa225ba3a63b1c upstream.

There are two reasons for addrconf_notify() to be called with NETDEV_DOWN:
either the network device is actually going down, or IPv6 was disabled
on the interface.

If either of them stays down while the other is toggled, we repeatedly
call the code for NETDEV_DOWN, including ipv6_mc_down(), while never
calling the corresponding ipv6_mc_up() in between. This will cause a
new entry in idev->mc_tomb to be allocated for each multicast group
the interface is subscribed to, which in turn leaks one struct ifmcaddr6
per nontrivial multicast group the interface is subscribed to.

The following reproducer will leak at least $n objects:

ip addr add ff2e::4242/32 dev eth0 autojoin
sysctl -w net.ipv6.conf.eth0.disable_ipv6=1
for i in $(seq 1 $n); do
	ip link set up eth0; ip link set down eth0
done

Joining groups with IPV6_ADD_MEMBERSHIP (unprivileged) or setting the
sysctl net.ipv6.conf.eth0.forwarding to 1 (=> subscribing to ff02::2)
can also be used to create a nontrivial idev->mc_list, which will the
leak objects with the right up-down-sequence.

Based on both sources for NETDEV_DOWN events the interface IPv6 state
should be considered:

 - not ready if the network interface is not ready OR IPv6 is disabled
   for it
 - ready if the network interface is ready AND IPv6 is enabled for it

The functions ipv6_mc_up() and ipv6_down() should only be run when this
state changes.

Implement this by remembering when the IPv6 state is ready, and only
run ipv6_mc_down() if it actually changed from ready to not ready.

The other direction (not ready -> ready) already works correctly, as:

 - the interface notification triggered codepath for NETDEV_UP /
   NETDEV_CHANGE returns early if ipv6 is disabled, and
 - the disable_ipv6=0 triggered codepath skips fully initializing the
   interface as long as addrconf_link_ready(dev) returns false
 - calling ipv6_mc_up() repeatedly does not leak anything

Fixes: 3ce62a84d53c ("ipv6: exit early in addrconf_notify() if IPv6 is disabled")
Signed-off-by: Johannes Nixdorf <j.nixdorf@avm.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
[jnixdorf: context updated for bpo to v4.9/v4.14]
Signed-off-by: Johannes Nixdorf <j.nixdorf@avm.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: ipv6: fix skb_over_panic in __ip6_append_data 2022-03-28T06:06:05+00:00 Tadeusz Struk tadeusz.struk@linaro.org 2022-03-10T23:25:38+00:00 08fe8723ffe50d76860dc8ea5ed16005e59c0d62 commit 5e34af4142ffe68f01c8a9acae83300f8911e20c upstream. Syzbot found a kernel bug in the ipv6 stack: LINK: https://syzkaller.appspot.com/bug?id=205d6f11d72329ab8d62a610c44c5e7e25415580 The reproducer triggers it by sending a crafted message via sendmmsg() call, which triggers skb_over_panic, and crashes the kernel: skbuff: skb_over_panic: text:ffffffff84647fb4 len:65575 put:65575 head:ffff888109ff0000 data:ffff888109ff0088 tail:0x100af end:0xfec0 dev:<NULL> Update the check that prevents an invalid packet with MTU equal to the fregment header size to eat up all the space for payload. The reproducer can be found here: LINK: https://syzkaller.appspot.com/text?tag=ReproC&x=1648c83fb00000 Reported-by: syzbot+e223cf47ec8ae183f2a0@syzkaller.appspotmail.com Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org> Acked-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/r/20220310232538.1044947-1-tadeusz.struk@linaro.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5e34af4142ffe68f01c8a9acae83300f8911e20c upstream.

Syzbot found a kernel bug in the ipv6 stack:
LINK: https://syzkaller.appspot.com/bug?id=205d6f11d72329ab8d62a610c44c5e7e25415580
The reproducer triggers it by sending a crafted message via sendmmsg()
call, which triggers skb_over_panic, and crashes the kernel:

skbuff: skb_over_panic: text:ffffffff84647fb4 len:65575 put:65575
head:ffff888109ff0000 data:ffff888109ff0088 tail:0x100af end:0xfec0
dev:<NULL>

Update the check that prevents an invalid packet with MTU equal
to the fregment header size to eat up all the space for payload.

The reproducer can be found here:
LINK: https://syzkaller.appspot.com/text?tag=ReproC&x=1648c83fb00000

Reported-by: syzbot+e223cf47ec8ae183f2a0@syzkaller.appspotmail.com
Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org>
Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20220310232538.1044947-1-tadeusz.struk@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xfrm: fix MTU regression 2022-03-08T18:00:57+00:00 Jiri Bohac jbohac@suse.cz 2022-01-19T09:22:53+00:00 80080bbcb25d386add6482aea9969e89834a8678 commit 6596a0229541270fb8d38d989f91b78838e5e9da upstream. Commit 749439bfac6e1a2932c582e2699f91d329658196 ("ipv6: fix udpv6 sendmsg crash caused by too small MTU") breaks PMTU for xfrm. A Packet Too Big ICMPv6 message received in response to an ESP packet will prevent all further communication through the tunnel if the reported MTU minus the ESP overhead is smaller than 1280. E.g. in a case of a tunnel-mode ESP with sha256/aes the overhead is 92 bytes. Receiving a PTB with MTU of 1371 or less will result in all further packets in the tunnel dropped. A ping through the tunnel fails with "ping: sendmsg: Invalid argument". Apparently the MTU on the xfrm route is smaller than 1280 and fails the check inside ip6_setup_cork() added by 749439bf. We found this by debugging USGv6/ipv6ready failures. Failing tests are: "Phase-2 Interoperability Test Scenario IPsec" / 5.3.11 and 5.4.11 (Tunnel Mode: Fragmentation). Commit b515d2637276a3810d6595e10ab02c13bfd0b63a ("xfrm: xfrm_state_mtu should return at least 1280 for ipv6") attempted to fix this but caused another regression in TCP MSS calculations and had to be reverted. The patch below fixes the situation by dropping the MTU check and instead checking for the underflows described in the 749439bf commit message. Signed-off-by: Jiri Bohac <jbohac@suse.cz> Fixes: 749439bfac6e ("ipv6: fix udpv6 sendmsg crash caused by too small MTU") Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6596a0229541270fb8d38d989f91b78838e5e9da upstream.

Commit 749439bfac6e1a2932c582e2699f91d329658196 ("ipv6: fix udpv6
sendmsg crash caused by too small MTU") breaks PMTU for xfrm.

A Packet Too Big ICMPv6 message received in response to an ESP
packet will prevent all further communication through the tunnel
if the reported MTU minus the ESP overhead is smaller than 1280.

E.g. in a case of a tunnel-mode ESP with sha256/aes the overhead
is 92 bytes. Receiving a PTB with MTU of 1371 or less will result
in all further packets in the tunnel dropped. A ping through the
tunnel fails with "ping: sendmsg: Invalid argument".

Apparently the MTU on the xfrm route is smaller than 1280 and
fails the check inside ip6_setup_cork() added by 749439bf.

We found this by debugging USGv6/ipv6ready failures. Failing
tests are: "Phase-2 Interoperability Test Scenario IPsec" /
5.3.11 and 5.4.11 (Tunnel Mode: Fragmentation).

Commit b515d2637276a3810d6595e10ab02c13bfd0b63a ("xfrm:
xfrm_state_mtu should return at least 1280 for ipv6") attempted
to fix this but caused another regression in TCP MSS calculations
and had to be reverted.

The patch below fixes the situation by dropping the MTU
check and instead checking for the underflows described in the
749439bf commit message.

Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Fixes: 749439bfac6e ("ipv6: fix udpv6 sendmsg crash caused by too small MTU")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gso: do not skip outer ip header in case of ipip and net_failover 2022-03-02T10:32:02+00:00 Tao Liu thomas.liu@ucloud.cn 2022-02-18T14:35:24+00:00 45d006c2c7ed7baf1fa258fa7b5bc9923d3a983e commit cc20cced0598d9a5ff91ae4ab147b3b5e99ee819 upstream. We encounter a tcp drop issue in our cloud environment. Packet GROed in host forwards to a VM virtio_net nic with net_failover enabled. VM acts as a IPVS LB with ipip encapsulation. The full path like: host gro -> vm virtio_net rx -> net_failover rx -> ipvs fullnat -> ipip encap -> net_failover tx -> virtio_net tx When net_failover transmits a ipip pkt (gso_type = 0x0103, which means SKB_GSO_TCPV4, SKB_GSO_DODGY and SKB_GSO_IPXIP4), there is no gso did because it supports TSO and GSO_IPXIP4. But network_header points to inner ip header. Call Trace: tcp4_gso_segment ------> return NULL inet_gso_segment ------> inner iph, network_header points to ipip_gso_segment inet_gso_segment ------> outer iph skb_mac_gso_segment Afterwards virtio_net transmits the pkt, only inner ip header is modified. And the outer one just keeps unchanged. The pkt will be dropped in remote host. Call Trace: inet_gso_segment ------> inner iph, outer iph is skipped skb_mac_gso_segment __skb_gso_segment validate_xmit_skb validate_xmit_skb_list sch_direct_xmit __qdisc_run __dev_queue_xmit ------> virtio_net dev_hard_start_xmit __dev_queue_xmit ------> net_failover ip_finish_output2 ip_output iptunnel_xmit ip_tunnel_xmit ipip_tunnel_xmit ------> ipip dev_hard_start_xmit __dev_queue_xmit ip_finish_output2 ip_output ip_forward ip_rcv __netif_receive_skb_one_core netif_receive_skb_internal napi_gro_receive receive_buf virtnet_poll net_rx_action The root cause of this issue is specific with the rare combination of SKB_GSO_DODGY and a tunnel device that adds an SKB_GSO_ tunnel option. SKB_GSO_DODGY is set from external virtio_net. We need to reset network header when callbacks.gso_segment() returns NULL. This patch also includes ipv6_gso_segment(), considering SIT, etc. Fixes: cb32f511a70b ("ipip: add GSO/TSO support") Signed-off-by: Tao Liu <thomas.liu@ucloud.cn> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit cc20cced0598d9a5ff91ae4ab147b3b5e99ee819 upstream.

We encounter a tcp drop issue in our cloud environment. Packet GROed in
host forwards to a VM virtio_net nic with net_failover enabled. VM acts
as a IPVS LB with ipip encapsulation. The full path like:
host gro -> vm virtio_net rx -> net_failover rx -> ipvs fullnat
 -> ipip encap -> net_failover tx -> virtio_net tx

When net_failover transmits a ipip pkt (gso_type = 0x0103, which means
SKB_GSO_TCPV4, SKB_GSO_DODGY and SKB_GSO_IPXIP4), there is no gso
did because it supports TSO and GSO_IPXIP4. But network_header points to
inner ip header.

Call Trace:
 tcp4_gso_segment        ------> return NULL
 inet_gso_segment        ------> inner iph, network_header points to
 ipip_gso_segment
 inet_gso_segment        ------> outer iph
 skb_mac_gso_segment

Afterwards virtio_net transmits the pkt, only inner ip header is modified.
And the outer one just keeps unchanged. The pkt will be dropped in remote
host.

Call Trace:
 inet_gso_segment        ------> inner iph, outer iph is skipped
 skb_mac_gso_segment
 __skb_gso_segment
 validate_xmit_skb
 validate_xmit_skb_list
 sch_direct_xmit
 __qdisc_run
 __dev_queue_xmit        ------> virtio_net
 dev_hard_start_xmit
 __dev_queue_xmit        ------> net_failover
 ip_finish_output2
 ip_output
 iptunnel_xmit
 ip_tunnel_xmit
 ipip_tunnel_xmit        ------> ipip
 dev_hard_start_xmit
 __dev_queue_xmit
 ip_finish_output2
 ip_output
 ip_forward
 ip_rcv
 __netif_receive_skb_one_core
 netif_receive_skb_internal
 napi_gro_receive
 receive_buf
 virtnet_poll
 net_rx_action

The root cause of this issue is specific with the rare combination of
SKB_GSO_DODGY and a tunnel device that adds an SKB_GSO_ tunnel option.
SKB_GSO_DODGY is set from external virtio_net. We need to reset network
header when callbacks.gso_segment() returns NULL.

This patch also includes ipv6_gso_segment(), considering SIT, etc.

Fixes: cb32f511a70b ("ipip: add GSO/TSO support")
Signed-off-by: Tao Liu <thomas.liu@ucloud.cn>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>