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  1. Nov 29, 2017
    • Eric Dumazet's avatar
      net/packet: fix a race in packet_bind() and packet_notifier() · 15fe076e
      Eric Dumazet authored
      syzbot reported crashes [1] and provided a C repro easing bug hunting.
      
      When/if packet_do_bind() calls __unregister_prot_hook() and releases
      po->bind_lock, another thread can run packet_notifier() and process an
      NETDEV_UP event.
      
      This calls register_prot_hook() and hooks again the socket right before
      first thread is able to grab again po->bind_lock.
      
      Fixes this issue by temporarily setting po->num to 0, as suggested by
      David Miller.
      
      [1]
      dev_remove_pack: ffff8801bf16fa80 not found
      ------------[ cut here ]------------
      kernel BUG at net/core/dev.c:7945!  ( BUG_ON(!list_empty(&dev->ptype_all)); )
      invalid opcode: 0000 [#1] SMP KASAN
      Dumping ftrace buffer:
         (ftrace buffer empty)
      Modules linked in:
      device syz0 entered promiscuous mode
      CPU: 0 PID: 3161 Comm: syzkaller404108 Not tainted 4.14.0+ #190
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      task: ffff8801cc57a500 task.stack: ffff8801cc588000
      RIP: 0010:netdev_run_todo+0x772/0xae0 net/core/dev.c:7945
      RSP: 0018:ffff8801cc58f598 EFLAGS: 00010293
      RAX: ffff8801cc57a500 RBX: dffffc0000000000 RCX: ffffffff841f75b2
      RDX: 0000000000000000 RSI: 1ffff100398b1ede RDI: ffff8801bf1f8810
      device syz0 entered promiscuous mode
      RBP: ffff8801cc58f898 R08: 0000000000000001 R09: 0000000000000000
      R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801bf1f8cd8
      R13: ffff8801cc58f870 R14: ffff8801bf1f8780 R15: ffff8801cc58f7f0
      FS:  0000000001716880(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000
      CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: 0000000020b13000 CR3: 0000000005e25000 CR4: 00000000001406f0
      DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
      Call Trace:
       rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:106
       tun_detach drivers/net/tun.c:670 [inline]
       tun_chr_close+0x49/0x60 drivers/net/tun.c:2845
       __fput+0x333/0x7f0 fs/file_table.c:210
       ____fput+0x15/0x20 fs/file_table.c:244
       task_work_run+0x199/0x270 kernel/task_work.c:113
       exit_task_work include/linux/task_work.h:22 [inline]
       do_exit+0x9bb/0x1ae0 kernel/exit.c:865
       do_group_exit+0x149/0x400 kernel/exit.c:968
       SYSC_exit_group kernel/exit.c:979 [inline]
       SyS_exit_group+0x1d/0x20 kernel/exit.c:977
       entry_SYSCALL_64_fastpath+0x1f/0x96
      RIP: 0033:0x44ad19
      
      Fixes: 30f7ea1c
      
       ("packet: race condition in packet_bind")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Cc: Francesco Ruggeri <fruggeri@aristanetworks.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      15fe076e
    • Mike Maloney's avatar
      packet: fix crash in fanout_demux_rollover() · 57f015f5
      Mike Maloney authored
      syzkaller found a race condition fanout_demux_rollover() while removing
      a packet socket from a fanout group.
      
      po->rollover is read and operated on during packet_rcv_fanout(), via
      fanout_demux_rollover(), but the pointer is currently cleared before the
      synchronization in packet_release().   It is safer to delay the cleanup
      until after synchronize_net() has been called, ensuring all calls to
      packet_rcv_fanout() for this socket have finished.
      
      To further simplify synchronization around the rollover structure, set
      po->rollover in fanout_add() only if there are no errors.  This removes
      the need for rcu in the struct and in the call to
      packet_getsockopt(..., PACKET_ROLLOVER_STATS, ...).
      
      Crashing stack trace:
       fanout_demux_rollover+0xb6/0x4d0 net/packet/af_packet.c:1392
       packet_rcv_fanout+0x649/0x7c8 net/packet/af_packet.c:1487
       dev_queue_xmit_nit+0x835/0xc10 net/core/dev.c:1953
       xmit_one net/core/dev.c:2975 [inline]
       dev_hard_start_xmit+0x16b/0xac0 net/core/dev.c:2995
       __dev_queue_xmit+0x17a4/0x2050 net/core/dev.c:3476
       dev_queue_xmit+0x17/0x20 net/core/dev.c:3509
       neigh_connected_output+0x489/0x720 net/core/neighbour.c:1379
       neigh_output include/net/neighbour.h:482 [inline]
       ip6_finish_output2+0xad1/0x22a0 net/ipv6/ip6_output.c:120
       ip6_finish_output+0x2f9/0x920 net/ipv6/ip6_output.c:146
       NF_HOOK_COND include/linux/netfilter.h:239 [inline]
       ip6_output+0x1f4/0x850 net/ipv6/ip6_output.c:163
       dst_output include/net/dst.h:459 [inline]
       NF_HOOK.constprop.35+0xff/0x630 include/linux/netfilter.h:250
       mld_sendpack+0x6a8/0xcc0 net/ipv6/mcast.c:1660
       mld_send_initial_cr.part.24+0x103/0x150 net/ipv6/mcast.c:2072
       mld_send_initial_cr net/ipv6/mcast.c:2056 [inline]
       ipv6_mc_dad_complete+0x99/0x130 net/ipv6/mcast.c:2079
       addrconf_dad_completed+0x595/0x970 net/ipv6/addrconf.c:4039
       addrconf_dad_work+0xac9/0x1160 net/ipv6/addrconf.c:3971
       process_one_work+0xbf0/0x1bc0 kernel/workqueue.c:2113
       worker_thread+0x223/0x1990 kernel/workqueue.c:2247
       kthread+0x35e/0x430 kernel/kthread.c:231
       ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:432
      
      Fixes: 0648ab70 ("packet: rollover prepare: per-socket state")
      Fixes: 509c7a1e
      
       ("packet: avoid panic in packet_getsockopt()")
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Signed-off-by: default avatarMike Maloney <maloney@google.com>
      Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      57f015f5
    • David S. Miller's avatar
      Merge branch 'sctp-fix-sparse-errors' · a51a40b7
      David S. Miller authored
      
      
      Xin Long says:
      
      ====================
      sctp: fix some other sparse errors
      
      After the last fixes for sparse errors, there are still three sparse
      errors in sctp codes, two of them are type cast, and the other one
      is using extern.
      ====================
      
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a51a40b7
    • Xin Long's avatar
      sctp: remove extern from stream sched · 1ba896f6
      Xin Long authored
      Now each stream sched ops is defined in different .c file and
      added into the global ops in another .c file, it uses extern
      to make this work.
      
      However extern is not good coding style to get them in and
      even make C=2 reports errors for this.
      
      This patch adds sctp_sched_ops_xxx_init for each stream sched
      ops in their .c file, then get them into the global ops by
      calling them when initializing sctp module.
      
      Fixes: 637784ad ("sctp: introduce priority based stream scheduler")
      Fixes: ac1ed8b8
      
       ("sctp: introduce round robin stream scheduler")
      Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
      Acked-by: default avatarMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1ba896f6
    • Xin Long's avatar
      sctp: force the params with right types for sctp csum apis · af2697a0
      Xin Long authored
      Now sctp_csum_xxx doesn't really match the param types of these common
      csum apis. As sctp_csum_xxx is defined in sctp/checksum.h, many sparse
      errors occur when make C=2 not only with M=net/sctp but also with other
      modules that include this header file.
      
      This patch is to force them fit in csum apis with the right types.
      
      Fixes: e6d8b64b
      
       ("net: sctp: fix and consolidate SCTP checksumming code")
      Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
      Acked-by: default avatarMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      af2697a0
    • Xin Long's avatar
      sctp: force SCTP_ERROR_INV_STRM with __u32 when calling sctp_chunk_fail · 08f46070
      Xin Long authored
      
      
      This patch is to force SCTP_ERROR_INV_STRM with right type to
      fit in sctp_chunk_fail to avoid the sparse error.
      
      Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
      Acked-by: default avatarMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      08f46070
  2. Nov 28, 2017
  3. Nov 27, 2017
  4. Nov 26, 2017