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  1. Mar 22, 2022
  2. Mar 17, 2022
  3. Mar 15, 2022
    • Eric Dumazet's avatar
      net/packet: fix slab-out-of-bounds access in packet_recvmsg() · c700525f
      Eric Dumazet authored
      syzbot found that when an AF_PACKET socket is using PACKET_COPY_THRESH
      and mmap operations, tpacket_rcv() is queueing skbs with
      garbage in skb->cb[], triggering a too big copy [1]
      
      Presumably, users of af_packet using mmap() already gets correct
      metadata from the mapped buffer, we can simply make sure
      to clear 12 bytes that might be copied to user space later.
      
      BUG: KASAN: stack-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline]
      BUG: KASAN: stack-out-of-bounds in packet_recvmsg+0x56c/0x1150 net/packet/af_packet.c:3489
      Write of size 165 at addr ffffc9000385fb78 by task syz-executor233/3631
      
      CPU: 0 PID: 3631 Comm: syz-executor233 Not tainted 5.17.0-rc7-syzkaller-02396-g0b3660695e80 #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+0xf/0x336 mm/kasan/report.c:255
       __kasan_report mm/kasan/report.c:442 [inline]
       kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
       check_region_inline mm/kasan/generic.c:183 [inline]
       kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
       memcpy+0x39/0x60 mm/kasan/shadow.c:66
       memcpy include/linux/fortify-string.h:225 [inline]
       packet_recvmsg+0x56c/0x1150 net/packet/af_packet.c:3489
       sock_recvmsg_nosec net/socket.c:948 [inline]
       sock_recvmsg net/socket.c:966 [inline]
       sock_recvmsg net/socket.c:962 [inline]
       ____sys_recvmsg+0x2c4/0x600 net/socket.c:2632
       ___sys_recvmsg+0x127/0x200 net/socket.c:2674
       __sys_recvmsg+0xe2/0x1a0 net/socket.c:2704
       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
      RIP: 0033:0x7fdfd5954c29
      Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
      RSP: 002b:00007ffcf8e71e48 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
      RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fdfd5954c29
      RDX: 0000000000000000 RSI: 0000000020000500 RDI: 0000000000000005
      RBP: 0000000000000000 R08: 000000000000000d R09: 000000000000000d
      R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcf8e71e60
      R13: 00000000000f4240 R14: 000000000000c1ff R15: 00007ffcf8e71e54
       </TASK>
      
      addr ffffc9000385fb78 is located in stack of task syz-executor233/3631 at offset 32 in frame:
       ____sys_recvmsg+0x0/0x600 include/linux/uio.h:246
      
      this frame has 1 object:
       [32, 160) 'addr'
      
      Memory state around the buggy address:
       ffffc9000385fa80: 00 04 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00 00
       ffffc9000385fb00: 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00
      >ffffc9000385fb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f3
                                                                      ^
       ffffc9000385fc00: f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 f1
       ffffc9000385fc80: f1 f1 f1 00 f2 f2 f2 00 f2 f2 f2 00 00 00 00 00
      ==================================================================
      
      Fixes: 0fb375fb
      
       ("[AF_PACKET]: Allow for > 8 byte hardware addresses.")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Link: https://lore.kernel.org/r/20220312232958.3535620-1-eric.dumazet@gmail.com
      
      
      Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      c700525f
  4. Mar 14, 2022
    • Sabrina Dubroca's avatar
      esp6: fix check on ipv6_skip_exthdr's return value · 4db4075f
      Sabrina Dubroca authored
      Commit 5f9c55c8 ("ipv6: check return value of ipv6_skip_exthdr")
      introduced an incorrect check, which leads to all ESP packets over
      either TCPv6 or UDPv6 encapsulation being dropped. In this particular
      case, offset is negative, since skb->data points to the ESP header in
      the following chain of headers, while skb->network_header points to
      the IPv6 header:
      
          IPv6 | ext | ... | ext | UDP | ESP | ...
      
      That doesn't seem to be a problem, especially considering that if we
      reach esp6_input_done2, we're guaranteed to have a full set of headers
      available (otherwise the packet would have been dropped earlier in the
      stack). However, it means that the return value will (intentionally)
      be negative. We can make the test more specific, as the expected
      return value of ipv6_skip_exthdr will be the (negated) size of either
      a UDP header, or a TCP header with possible options.
      
      In the future, we should probably either make ipv6_skip_exthdr
      explicitly accept negative offsets (and adjust its return value for
      error cases), or make ipv6_skip_exthdr only take non-negative
      offsets (and audit all callers).
      
      Fixes: 5f9c55c8
      
       ("ipv6: check return value of ipv6_skip_exthdr")
      Reported-by: default avatarXiumei Mu <xmu@redhat.com>
      Signed-off-by: default avatarSabrina Dubroca <sd@queasysnail.net>
      Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
      4db4075f
  5. Mar 12, 2022
  6. Mar 11, 2022
  7. Mar 10, 2022
    • Sebastian Andrzej Siewior's avatar
      xdp: xdp_mem_allocator can be NULL in trace_mem_connect(). · e0ae7130
      Sebastian Andrzej Siewior authored
      Since the commit mentioned below __xdp_reg_mem_model() can return a NULL
      pointer. This pointer is dereferenced in trace_mem_connect() which leads
      to segfault.
      
      The trace points (mem_connect + mem_disconnect) were put in place to
      pair connect/disconnect using the IDs. The ID is only assigned if
      __xdp_reg_mem_model() does not return NULL. That connect trace point is
      of no use if there is no ID.
      
      Skip that connect trace point if xdp_alloc is NULL.
      
      [ Toke Høiland-Jørgensen delivered the reasoning for skipping the trace
        point ]
      
      Fixes: 4a48ef70
      
       ("xdp: Allow registering memory model without rxq reference")
      Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
      Acked-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
      Link: https://lore.kernel.org/r/YikmmXsffE+QajTB@linutronix.de
      
      
      Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      e0ae7130
    • Eric Dumazet's avatar
      sctp: fix kernel-infoleak for SCTP sockets · 633593a8
      Eric Dumazet authored
      syzbot reported a kernel infoleak [1] of 4 bytes.
      
      After analysis, it turned out r->idiag_expires is not initialized
      if inet_sctp_diag_fill() calls inet_diag_msg_common_fill()
      
      Make sure to clear idiag_timer/idiag_retrans/idiag_expires
      and let inet_diag_msg_sctpasoc_fill() fill them again if needed.
      
      [1]
      
      BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline]
      BUG: KMSAN: kernel-infoleak in copyout lib/iov_iter.c:154 [inline]
      BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x6ef/0x25a0 lib/iov_iter.c:668
       instrument_copy_to_user include/linux/instrumented.h:121 [inline]
       copyout lib/iov_iter.c:154 [inline]
       _copy_to_iter+0x6ef/0x25a0 lib/iov_iter.c:668
       copy_to_iter include/linux/uio.h:162 [inline]
       simple_copy_to_iter+0xf3/0x140 net/core/datagram.c:519
       __skb_datagram_iter+0x2d5/0x11b0 net/core/datagram.c:425
       skb_copy_datagram_iter+0xdc/0x270 net/core/datagram.c:533
       skb_copy_datagram_msg include/linux/skbuff.h:3696 [inline]
       netlink_recvmsg+0x669/0x1c80 net/netlink/af_netlink.c:1977
       sock_recvmsg_nosec net/socket.c:948 [inline]
       sock_recvmsg net/socket.c:966 [inline]
       __sys_recvfrom+0x795/0xa10 net/socket.c:2097
       __do_sys_recvfrom net/socket.c:2115 [inline]
       __se_sys_recvfrom net/socket.c:2111 [inline]
       __x64_sys_recvfrom+0x19d/0x210 net/socket.c:2111
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x44/0xae
      
      Uninit was created at:
       slab_post_alloc_hook mm/slab.h:737 [inline]
       slab_alloc_node mm/slub.c:3247 [inline]
       __kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4975
       kmalloc_reserve net/core/skbuff.c:354 [inline]
       __alloc_skb+0x545/0xf90 net/core/skbuff.c:426
       alloc_skb include/linux/skbuff.h:1158 [inline]
       netlink_dump+0x3e5/0x16c0 net/netlink/af_netlink.c:2248
       __netlink_dump_start+0xcf8/0xe90 net/netlink/af_netlink.c:2373
       netlink_dump_start include/linux/netlink.h:254 [inline]
       inet_diag_handler_cmd+0x2e7/0x400 net/ipv4/inet_diag.c:1341
       sock_diag_rcv_msg+0x24a/0x620
       netlink_rcv_skb+0x40c/0x7e0 net/netlink/af_netlink.c:2494
       sock_diag_rcv+0x63/0x80 net/core/sock_diag.c:277
       netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
       netlink_unicast+0x1093/0x1360 net/netlink/af_netlink.c:1343
       netlink_sendmsg+0x14d9/0x1720 net/netlink/af_netlink.c:1919
       sock_sendmsg_nosec net/socket.c:705 [inline]
       sock_sendmsg net/socket.c:725 [inline]
       sock_write_iter+0x594/0x690 net/socket.c:1061
       do_iter_readv_writev+0xa7f/0xc70
       do_iter_write+0x52c/0x1500 fs/read_write.c:851
       vfs_writev fs/read_write.c:924 [inline]
       do_writev+0x645/0xe00 fs/read_write.c:967
       __do_sys_writev fs/read_write.c:1040 [inline]
       __se_sys_writev fs/read_write.c:1037 [inline]
       __x64_sys_writev+0xe5/0x120 fs/read_write.c:1037
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x44/0xae
      
      Bytes 68-71 of 2508 are uninitialized
      Memory access of size 2508 starts at ffff888114f9b000
      Data copied to user address 00007f7fe09ff2e0
      
      CPU: 1 PID: 3478 Comm: syz-executor306 Not tainted 5.17.0-rc4-syzkaller #0
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      
      Fixes: 8f840e47
      
       ("sctp: add the sctp_diag.c file")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Cc: Vlad Yasevich <vyasevich@gmail.com>
      Cc: Neil Horman <nhorman@tuxdriver.com>
      Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
      Reviewed-by: default avatarXin Long <lucien.xin@gmail.com>
      Link: https://lore.kernel.org/r/20220310001145.297371-1-eric.dumazet@gmail.com
      
      
      Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      633593a8
    • Haimin Zhang's avatar
      af_key: add __GFP_ZERO flag for compose_sadb_supported in function pfkey_register · 9a564bcc
      Haimin Zhang authored
      
      Add __GFP_ZERO flag for compose_sadb_supported in function pfkey_register
      to initialize the buffer of supp_skb to fix a kernel-info-leak issue.
      1) Function pfkey_register calls compose_sadb_supported to request
      a sk_buff. 2) compose_sadb_supported calls alloc_sbk to allocate
      a sk_buff, but it doesn't zero it. 3) If auth_len is greater 0, then
      compose_sadb_supported treats the memory as a struct sadb_supported and
      begins to initialize. But it just initializes the field sadb_supported_len
      and field sadb_supported_exttype without field sadb_supported_reserved.
      
      Reported-by: default avatarTCS Robot <tcs_robot@tencent.com>
      Signed-off-by: default avatarHaimin Zhang <tcs_kernel@tencent.com>
      Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
      9a564bcc
  8. Mar 09, 2022
    • Duoming Zhou's avatar
      ax25: Fix NULL pointer dereference in ax25_kill_by_device · 71171ac8
      Duoming Zhou authored
      When two ax25 devices attempted to establish connection, the requester use ax25_create(),
      ax25_bind() and ax25_connect() to initiate connection. The receiver use ax25_rcv() to
      accept connection and use ax25_create_cb() in ax25_rcv() to create ax25_cb, but the
      ax25_cb->sk is NULL. When the receiver is detaching, a NULL pointer dereference bug
      caused by sock_hold(sk) in ax25_kill_by_device() will happen. The corresponding
      fail log is shown below:
      
      ===============================================================
      BUG: KASAN: null-ptr-deref in ax25_device_event+0xfd/0x290
      Call Trace:
      ...
      ax25_device_event+0xfd/0x290
      raw_notifier_call_chain+0x5e/0x70
      dev_close_many+0x174/0x220
      unregister_netdevice_many+0x1f7/0xa60
      unregister_netdevice_queue+0x12f/0x170
      unregister_netdev+0x13/0x20
      mkiss_close+0xcd/0x140
      tty_ldisc_release+0xc0/0x220
      tty_release_struct+0x17/0xa0
      tty_release+0x62d/0x670
      ...
      
      This patch add condition check in ax25_kill_by_device(). If s->sk is
      NULL, it will goto if branch to kill device.
      
      Fixes: 4e0f718d
      
       ("ax25: improve the incomplete fix to avoid UAF and NPD bugs")
      Reported-by: default avatarThomas Osterried <thomas@osterried.de>
      Signed-off-by: default avatarDuoming Zhou <duoming@zju.edu.cn>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      71171ac8
    • Tung Nguyen's avatar
      tipc: fix incorrect order of state message data sanity check · c79fcc27
      Tung Nguyen authored
      When receiving a state message, function tipc_link_validate_msg()
      is called to validate its header portion. Then, its data portion
      is validated before it can be accessed correctly. However, current
      data sanity  check is done after the message header is accessed to
      update some link variables.
      
      This commit fixes this issue by moving the data sanity check to
      the beginning of state message handling and right after the header
      sanity check.
      
      Fixes: 9aa422ad
      
       ("tipc: improve size validations for received domain records")
      Acked-by: default avatarJon Maloy <jmaloy@redhat.com>
      Signed-off-by: default avatarTung Nguyen <tung.q.nguyen@dektech.com.au>
      Link: https://lore.kernel.org/r/20220308021200.9245-1-tung.q.nguyen@dektech.com.au
      
      
      Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      c79fcc27
  9. Mar 08, 2022
  10. Mar 07, 2022
    • Steffen Klassert's avatar
      net: Fix esp GSO on inter address family tunnels. · 23c7f8d7
      Steffen Klassert authored
      The esp tunnel GSO handlers use skb_mac_gso_segment to
      push the inner packet to the segmentation handlers.
      However, skb_mac_gso_segment takes the Ethernet Protocol
      ID from 'skb->protocol' which is wrong for inter address
      family tunnels. We fix this by introducing a new
      skb_eth_gso_segment function.
      
      This function can be used if it is necessary to pass the
      Ethernet Protocol ID directly to the segmentation handler.
      First users of this function will be the esp4 and esp6
      tunnel segmentation handlers.
      
      Fixes: c35fe410
      
       ("xfrm: Add mode handlers for IPsec on layer 2")
      Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
      23c7f8d7
    • Steffen Klassert's avatar
      esp: Fix BEET mode inter address family tunneling on GSO · 053c8fdf
      Steffen Klassert authored
      The xfrm{4,6}_beet_gso_segment() functions did not correctly set the
      SKB_GSO_IPXIP4 and SKB_GSO_IPXIP6 gso types for the address family
      tunneling case. Fix this by setting these gso types.
      
      Fixes: 384a46ea ("esp4: add gso_segment for esp4 beet mode")
      Fixes: 7f9e40eb
      
       ("esp6: add gso_segment for esp6 beet mode")
      Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
      053c8fdf
    • Steffen Klassert's avatar
      esp: Fix possible buffer overflow in ESP transformation · ebe48d36
      Steffen Klassert authored
      The maximum message size that can be send is bigger than
      the  maximum site that skb_page_frag_refill can allocate.
      So it is possible to write beyond the allocated buffer.
      
      Fix this by doing a fallback to COW in that case.
      
      v2:
      
      Avoid get get_order() costs as suggested by Linus Torvalds.
      
      Fixes: cac2661c ("esp4: Avoid skb_cow_data whenever possible")
      Fixes: 03e2a30f
      
       ("esp6: Avoid skb_cow_data whenever possible")
      Reported-by: default avatarvalis <sec@valis.email>
      Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
      ebe48d36
    • Juergen Gross's avatar
      xen/9p: use alloc/free_pages_exact() · 5cadd4bb
      Juergen Gross authored
      
      Instead of __get_free_pages() and free_pages() use alloc_pages_exact()
      and free_pages_exact(). This is in preparation of a change of
      gnttab_end_foreign_access() which will prohibit use of high-order
      pages.
      
      By using the local variable "order" instead of ring->intf->ring_order
      in the error path of xen_9pfs_front_alloc_dataring() another bug is
      fixed, as the error path can be entered before ring->intf->ring_order
      is being set.
      
      By using alloc_pages_exact() the size in bytes is specified for the
      allocation, which fixes another bug for the case of
      order < (PAGE_SHIFT - XEN_PAGE_SHIFT).
      
      This is part of CVE-2022-23041 / XSA-396.
      
      Reported-by: default avatarSimon Gaiser <simon@invisiblethingslab.com>
      Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
      Reviewed-by: default avatarJan Beulich <jbeulich@suse.com>
      ---
      V4:
      - new patch
      5cadd4bb
  11. Mar 06, 2022
  12. Mar 04, 2022
    • Tung Nguyen's avatar
      tipc: fix kernel panic when enabling bearer · be4977b8
      Tung Nguyen authored
      When enabling a bearer on a node, a kernel panic is observed:
      
      [    4.498085] RIP: 0010:tipc_mon_prep+0x4e/0x130 [tipc]
      ...
      [    4.520030] Call Trace:
      [    4.520689]  <IRQ>
      [    4.521236]  tipc_link_build_proto_msg+0x375/0x750 [tipc]
      [    4.522654]  tipc_link_build_state_msg+0x48/0xc0 [tipc]
      [    4.524034]  __tipc_node_link_up+0xd7/0x290 [tipc]
      [    4.525292]  tipc_rcv+0x5da/0x730 [tipc]
      [    4.526346]  ? __netif_receive_skb_core+0xb7/0xfc0
      [    4.527601]  tipc_l2_rcv_msg+0x5e/0x90 [tipc]
      [    4.528737]  __netif_receive_skb_list_core+0x20b/0x260
      [    4.530068]  netif_receive_skb_list_internal+0x1bf/0x2e0
      [    4.531450]  ? dev_gro_receive+0x4c2/0x680
      [    4.532512]  napi_complete_done+0x6f/0x180
      [    4.533570]  virtnet_poll+0x29c/0x42e [virtio_net]
      ...
      
      The node in question is receiving activate messages in another
      thread after changing bearer status to allow message sending/
      receiving in current thread:
      
               thread 1           |              thread 2
               --------           |              --------
                                  |
      tipc_enable_bearer()        |
        test_and_set_bit_lock()   |
          tipc_bearer_xmit_skb()  |
                                  | tipc_l2_rcv_msg()
                                  |   tipc_rcv()
                                  |     __tipc_node_link_up()
                                  |       tipc_link_build_state_msg()
                                  |         tipc_link_build_proto_msg()
                                  |           tipc_mon_prep()
                                  |           {
                                  |             ...
                                  |             // null-pointer dereference
                                  |             u16 gen = mon->dom_gen;
                                  |             ...
                                  |           }
        // Not being executed yet |
        tipc_mon_create()         |
        {                         |
          ...                     |
          // allocate             |
          mon = kzalloc();        |
          ...                     |
        }                         |
      
      Monitoring pointer in thread 2 is dereferenced before monitoring data
      is allocated in thread 1. This causes kernel panic.
      
      This commit fixes it by allocating the monitoring data before enabling
      the bearer to receive messages.
      
      Fixes: 35c55c98
      
       ("tipc: add neighbor monitoring framework")
      Reported-by: default avatarShuang Li <shuali@redhat.com>
      Acked-by: default avatarJon Maloy <jmaloy@redhat.com>
      Signed-off-by: default avatarTung Nguyen <tung.q.nguyen@dektech.com.au>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      be4977b8
  13. Mar 03, 2022
  14. Mar 02, 2022
    • Sreeramya Soratkal's avatar
      nl80211: Update bss channel on channel switch for P2P_CLIENT · e50b88c4
      Sreeramya Soratkal authored
      
      The wdev channel information is updated post channel switch only for
      the station mode and not for the other modes. Due to this, the P2P client
      still points to the old value though it moved to the new channel
      when the channel change is induced from the P2P GO.
      
      Update the bss channel after CSA channel switch completion for P2P client
      interface as well.
      
      Signed-off-by: default avatarSreeramya Soratkal <quic_ssramya@quicinc.com>
      Link: https://lore.kernel.org/r/1646114600-31479-1-git-send-email-quic_ssramya@quicinc.com
      
      
      Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      e50b88c4
    • Sven Eckelmann's avatar
      batman-adv: Don't expect inter-netns unique iflink indices · 6c1f41af
      Sven Eckelmann authored
      The ifindex doesn't have to be unique for multiple network namespaces on
      the same machine.
      
        $ ip netns add test1
        $ ip -net test1 link add dummy1 type dummy
        $ ip netns add test2
        $ ip -net test2 link add dummy2 type dummy
      
        $ ip -net test1 link show dev dummy1
        6: dummy1: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
            link/ether 96:81:55:1e:dd:85 brd ff:ff:ff:ff:ff:ff
        $ ip -net test2 link show dev dummy2
        6: dummy2: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
            link/ether 5a:3c:af:35:07:c3 brd ff:ff:ff:ff:ff:ff
      
      But the batman-adv code to walk through the various layers of virtual
      interfaces uses this assumption because dev_get_iflink handles it
      internally and doesn't return the actual netns of the iflink. And
      dev_get_iflink only documents the situation where ifindex == iflink for
      physical devices.
      
      But only checking for dev->netdev_ops->ndo_get_iflink is also not an option
      because ipoib_get_iflink implements it even when it sometimes returns an
      iflink != ifindex and sometimes iflink == ifindex. The caller must
      therefore make sure itself to check both netns and iflink + ifindex for
      equality. Only when they are equal, a "physical" interface was detected
      which should stop the traversal. On the other hand, vxcan_get_iflink can
      also return 0 in case there was currently no valid peer. In this case, it
      is still necessary to stop.
      
      Fixes: b7eddd0b ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface")
      Fixes: 5ed4a460
      
       ("batman-adv: additional checks for virtual interfaces on top of WiFi")
      Reported-by: default avatarSabrina Dubroca <sd@queasysnail.net>
      Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
      Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
      6c1f41af
    • Sven Eckelmann's avatar
      batman-adv: Request iflink once in batadv_get_real_netdevice · 6116ba09
      Sven Eckelmann authored
      There is no need to call dev_get_iflink multiple times for the same
      net_device in batadv_get_real_netdevice. And since some of the
      ndo_get_iflink callbacks are dynamic (for example via RCUs like in
      vxcan_get_iflink), it could easily happen that the returned values are not
      stable. The pre-checks before __dev_get_by_index are then of course bogus.
      
      Fixes: 5ed4a460
      
       ("batman-adv: additional checks for virtual interfaces on top of WiFi")
      Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
      Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
      6116ba09
    • Sven Eckelmann's avatar
      batman-adv: Request iflink once in batadv-on-batadv check · 690bb6fb
      Sven Eckelmann authored
      There is no need to call dev_get_iflink multiple times for the same
      net_device in batadv_is_on_batman_iface. And since some of the
      .ndo_get_iflink callbacks are dynamic (for example via RCUs like in
      vxcan_get_iflink), it could easily happen that the returned values are not
      stable. The pre-checks before __dev_get_by_index are then of course bogus.
      
      Fixes: b7eddd0b
      
       ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface")
      Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
      Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
      690bb6fb
  15. Mar 01, 2022