1. 18 Apr, 2017 7 commits
    • Eric Dumazet's avatar
      ipv4: keep skb->dst around in presence of IP options · eeae5e03
      Eric Dumazet authored
      [ Upstream commit 34b2cef2 ]
      
      Andrey Konovalov got crashes in __ip_options_echo() when a NULL skb->dst
      is accessed.
      
      ipv4_pktinfo_prepare() should not drop the dst if (evil) IP options
      are present.
      
      We could refine the test to the presence of ts_needtime or srr,
      but IP options are not often used, so let's be conservative.
      
      Thanks to syzkaller team for finding this bug.
      
      Fixes: d826eb14 ("ipv4: PKTINFO doesnt need dst reference")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      eeae5e03
    • Eric Dumazet's avatar
      net: use a work queue to defer net_disable_timestamp() work · 1d3dbc1d
      Eric Dumazet authored
      [ Upstream commit 5fa8bbda ]
      
      Dmitry reported a warning [1] showing that we were calling
      net_disable_timestamp() -> static_key_slow_dec() from a non
      process context.
      
      Grabbing a mutex while holding a spinlock or rcu_read_lock()
      is not allowed.
      
      As Cong suggested, we now use a work queue.
      
      It is possible netstamp_clear() exits while netstamp_needed_deferred
      is not zero, but it is probably not worth trying to do better than that.
      
      netstamp_needed_deferred atomic tracks the exact number of deferred
      decrements.
      
      [1]
      [ INFO: suspicious RCU usage. ]
      4.10.0-rc5+ #192 Not tainted
      -------------------------------
      ./include/linux/rcupdate.h:561 Illegal context switch in RCU read-side
      critical section!
      
      other info that might help us debug this:
      
      rcu_scheduler_active = 2, debug_locks = 0
      2 locks held by syz-executor14/23111:
       #0:  (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff83a35c35>] lock_sock
      include/net/sock.h:1454 [inline]
       #0:  (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff83a35c35>]
      rawv6_sendmsg+0x1e65/0x3ec0 net/ipv6/raw.c:919
       #1:  (rcu_read_lock){......}, at: [<ffffffff83ae2678>] nf_hook
      include/linux/netfilter.h:201 [inline]
       #1:  (rcu_read_lock){......}, at: [<ffffffff83ae2678>]
      __ip6_local_out+0x258/0x840 net/ipv6/output_core.c:160
      
      stack backtrace:
      CPU: 2 PID: 23111 Comm: syz-executor14 Not tainted 4.10.0-rc5+ #192
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
      01/01/2011
      Call Trace:
       __dump_stack lib/dump_stack.c:15 [inline]
       dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
       lockdep_rcu_suspicious+0x139/0x180 kernel/locking/lockdep.c:4452
       rcu_preempt_sleep_check include/linux/rcupdate.h:560 [inline]
       ___might_sleep+0x560/0x650 kernel/sched/core.c:7748
       __might_sleep+0x95/0x1a0 kernel/sched/core.c:7739
       mutex_lock_nested+0x24f/0x1730 kernel/locking/mutex.c:752
       atomic_dec_and_mutex_lock+0x119/0x160 kernel/locking/mutex.c:1060
       __static_key_slow_dec+0x7a/0x1e0 kernel/jump_label.c:149
       static_key_slow_dec+0x51/0x90 kernel/jump_label.c:174
       net_disable_timestamp+0x3b/0x50 net/core/dev.c:1728
       sock_disable_timestamp+0x98/0xc0 net/core/sock.c:403
       __sk_destruct+0x27d/0x6b0 net/core/sock.c:1441
       sk_destruct+0x47/0x80 net/core/sock.c:1460
       __sk_free+0x57/0x230 net/core/sock.c:1468
       sock_wfree+0xae/0x120 net/core/sock.c:1645
       skb_release_head_state+0xfc/0x200 net/core/skbuff.c:655
       skb_release_all+0x15/0x60 net/core/skbuff.c:668
       __kfree_skb+0x15/0x20 net/core/skbuff.c:684
       kfree_skb+0x16e/0x4c0 net/core/skbuff.c:705
       inet_frag_destroy+0x121/0x290 net/ipv4/inet_fragment.c:304
       inet_frag_put include/net/inet_frag.h:133 [inline]
       nf_ct_frag6_gather+0x1106/0x3840
      net/ipv6/netfilter/nf_conntrack_reasm.c:617
       ipv6_defrag+0x1be/0x2b0 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:68
       nf_hook_entry_hookfn include/linux/netfilter.h:102 [inline]
       nf_hook_slow+0xc3/0x290 net/netfilter/core.c:310
       nf_hook include/linux/netfilter.h:212 [inline]
       __ip6_local_out+0x489/0x840 net/ipv6/output_core.c:160
       ip6_local_out+0x2d/0x170 net/ipv6/output_core.c:170
       ip6_send_skb+0xa1/0x340 net/ipv6/ip6_output.c:1722
       ip6_push_pending_frames+0xb3/0xe0 net/ipv6/ip6_output.c:1742
       rawv6_push_pending_frames net/ipv6/raw.c:613 [inline]
       rawv6_sendmsg+0x2d1a/0x3ec0 net/ipv6/raw.c:927
       inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:744
       sock_sendmsg_nosec net/socket.c:635 [inline]
       sock_sendmsg+0xca/0x110 net/socket.c:645
       sock_write_iter+0x326/0x600 net/socket.c:848
       do_iter_readv_writev+0x2e3/0x5b0 fs/read_write.c:695
       do_readv_writev+0x42c/0x9b0 fs/read_write.c:872
       vfs_writev+0x87/0xc0 fs/read_write.c:911
       do_writev+0x110/0x2c0 fs/read_write.c:944
       SYSC_writev fs/read_write.c:1017 [inline]
       SyS_writev+0x27/0x30 fs/read_write.c:1014
       entry_SYSCALL_64_fastpath+0x1f/0xc2
      RIP: 0033:0x445559
      RSP: 002b:00007f6f46fceb58 EFLAGS: 00000292 ORIG_RAX: 0000000000000014
      RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000445559
      RDX: 0000000000000001 RSI: 0000000020f1eff0 RDI: 0000000000000005
      RBP: 00000000006e19c0 R08: 0000000000000000 R09: 0000000000000000
      R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000700000
      R13: 0000000020f59000 R14: 0000000000000015 R15: 0000000000020400
      BUG: sleeping function called from invalid context at
      kernel/locking/mutex.c:752
      in_atomic(): 1, irqs_disabled(): 0, pid: 23111, name: syz-executor14
      INFO: lockdep is turned off.
      CPU: 2 PID: 23111 Comm: syz-executor14 Not tainted 4.10.0-rc5+ #192
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
      01/01/2011
      Call Trace:
       __dump_stack lib/dump_stack.c:15 [inline]
       dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
       ___might_sleep+0x47e/0x650 kernel/sched/core.c:7780
       __might_sleep+0x95/0x1a0 kernel/sched/core.c:7739
       mutex_lock_nested+0x24f/0x1730 kernel/locking/mutex.c:752
       atomic_dec_and_mutex_lock+0x119/0x160 kernel/locking/mutex.c:1060
       __static_key_slow_dec+0x7a/0x1e0 kernel/jump_label.c:149
       static_key_slow_dec+0x51/0x90 kernel/jump_label.c:174
       net_disable_timestamp+0x3b/0x50 net/core/dev.c:1728
       sock_disable_timestamp+0x98/0xc0 net/core/sock.c:403
       __sk_destruct+0x27d/0x6b0 net/core/sock.c:1441
       sk_destruct+0x47/0x80 net/core/sock.c:1460
       __sk_free+0x57/0x230 net/core/sock.c:1468
       sock_wfree+0xae/0x120 net/core/sock.c:1645
       skb_release_head_state+0xfc/0x200 net/core/skbuff.c:655
       skb_release_all+0x15/0x60 net/core/skbuff.c:668
       __kfree_skb+0x15/0x20 net/core/skbuff.c:684
       kfree_skb+0x16e/0x4c0 net/core/skbuff.c:705
       inet_frag_destroy+0x121/0x290 net/ipv4/inet_fragment.c:304
       inet_frag_put include/net/inet_frag.h:133 [inline]
       nf_ct_frag6_gather+0x1106/0x3840
      net/ipv6/netfilter/nf_conntrack_reasm.c:617
       ipv6_defrag+0x1be/0x2b0 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:68
       nf_hook_entry_hookfn include/linux/netfilter.h:102 [inline]
       nf_hook_slow+0xc3/0x290 net/netfilter/core.c:310
       nf_hook include/linux/netfilter.h:212 [inline]
       __ip6_local_out+0x489/0x840 net/ipv6/output_core.c:160
       ip6_local_out+0x2d/0x170 net/ipv6/output_core.c:170
       ip6_send_skb+0xa1/0x340 net/ipv6/ip6_output.c:1722
       ip6_push_pending_frames+0xb3/0xe0 net/ipv6/ip6_output.c:1742
       rawv6_push_pending_frames net/ipv6/raw.c:613 [inline]
       rawv6_sendmsg+0x2d1a/0x3ec0 net/ipv6/raw.c:927
       inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:744
       sock_sendmsg_nosec net/socket.c:635 [inline]
       sock_sendmsg+0xca/0x110 net/socket.c:645
       sock_write_iter+0x326/0x600 net/socket.c:848
       do_iter_readv_writev+0x2e3/0x5b0 fs/read_write.c:695
       do_readv_writev+0x42c/0x9b0 fs/read_write.c:872
       vfs_writev+0x87/0xc0 fs/read_write.c:911
       do_writev+0x110/0x2c0 fs/read_write.c:944
       SYSC_writev fs/read_write.c:1017 [inline]
       SyS_writev+0x27/0x30 fs/read_write.c:1014
       entry_SYSCALL_64_fastpath+0x1f/0xc2
      RIP: 0033:0x445559
      
      Fixes: b90e5794 ("net: dont call jump_label_dec from irq context")
      Suggested-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1d3dbc1d
    • Eric Dumazet's avatar
      tcp: fix 0 divide in __tcp_select_window() · 457432f3
      Eric Dumazet authored
      [ Upstream commit 06425c30 ]
      
      syszkaller fuzzer was able to trigger a divide by zero, when
      TCP window scaling is not enabled.
      
      SO_RCVBUF can be used not only to increase sk_rcvbuf, also
      to decrease it below current receive buffers utilization.
      
      If mss is negative or 0, just return a zero TCP window.
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarDmitry Vyukov  <dvyukov@google.com>
      Acked-by: default avatarNeal Cardwell <ncardwell@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      457432f3
    • Dan Carpenter's avatar
      ipv6: pointer math error in ip6_tnl_parse_tlv_enc_lim() · a5042c99
      Dan Carpenter authored
      [ Upstream commit 63117f09 ]
      
      Casting is a high precedence operation but "off" and "i" are in terms of
      bytes so we need to have some parenthesis here.
      
      Fixes: fbfa743a ("ipv6: fix ip6_tnl_parse_tlv_enc_lim()")
      Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Acked-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a5042c99
    • Eric Dumazet's avatar
      ipv6: fix ip6_tnl_parse_tlv_enc_lim() · d397f703
      Eric Dumazet authored
      [ Upstream commit fbfa743a ]
      
      This function suffers from multiple issues.
      
      First one is that pskb_may_pull() may reallocate skb->head,
      so the 'raw' pointer needs either to be reloaded or not used at all.
      
      Second issue is that NEXTHDR_DEST handling does not validate
      that the options are present in skb->data, so we might read
      garbage or access non existent memory.
      
      With help from Willem de Bruijn.
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarDmitry Vyukov  <dvyukov@google.com>
      Cc: Willem de Bruijn <willemb@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d397f703
    • Eric Dumazet's avatar
      can: Fix kernel panic at security_sock_rcv_skb · 2b88a4ce
      Eric Dumazet authored
      [ Upstream commit f1712c73 ]
      
      Zhang Yanmin reported crashes [1] and provided a patch adding a
      synchronize_rcu() call in can_rx_unregister()
      
      The main problem seems that the sockets themselves are not RCU
      protected.
      
      If CAN uses RCU for delivery, then sockets should be freed only after
      one RCU grace period.
      
      Recent kernels could use sock_set_flag(sk, SOCK_RCU_FREE), but let's
      ease stable backports with the following fix instead.
      
      [1]
      BUG: unable to handle kernel NULL pointer dereference at (null)
      IP: [<ffffffff81495e25>] selinux_socket_sock_rcv_skb+0x65/0x2a0
      
      Call Trace:
       <IRQ>
       [<ffffffff81485d8c>] security_sock_rcv_skb+0x4c/0x60
       [<ffffffff81d55771>] sk_filter+0x41/0x210
       [<ffffffff81d12913>] sock_queue_rcv_skb+0x53/0x3a0
       [<ffffffff81f0a2b3>] raw_rcv+0x2a3/0x3c0
       [<ffffffff81f06eab>] can_rcv_filter+0x12b/0x370
       [<ffffffff81f07af9>] can_receive+0xd9/0x120
       [<ffffffff81f07beb>] can_rcv+0xab/0x100
       [<ffffffff81d362ac>] __netif_receive_skb_core+0xd8c/0x11f0
       [<ffffffff81d36734>] __netif_receive_skb+0x24/0xb0
       [<ffffffff81d37f67>] process_backlog+0x127/0x280
       [<ffffffff81d36f7b>] net_rx_action+0x33b/0x4f0
       [<ffffffff810c88d4>] __do_softirq+0x184/0x440
       [<ffffffff81f9e86c>] do_softirq_own_stack+0x1c/0x30
       <EOI>
       [<ffffffff810c76fb>] do_softirq.part.18+0x3b/0x40
       [<ffffffff810c8bed>] do_softirq+0x1d/0x20
       [<ffffffff81d30085>] netif_rx_ni+0xe5/0x110
       [<ffffffff8199cc87>] slcan_receive_buf+0x507/0x520
       [<ffffffff8167ef7c>] flush_to_ldisc+0x21c/0x230
       [<ffffffff810e3baf>] process_one_work+0x24f/0x670
       [<ffffffff810e44ed>] worker_thread+0x9d/0x6f0
       [<ffffffff810e4450>] ? rescuer_thread+0x480/0x480
       [<ffffffff810ebafc>] kthread+0x12c/0x150
       [<ffffffff81f9ccef>] ret_from_fork+0x3f/0x70
      Reported-by: default avatarZhang Yanmin <yanmin.zhang@intel.com>
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Acked-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2b88a4ce
    • Linus Torvalds's avatar
      Revert "af_unix: Fix splice-bind deadlock" · 9547c9a2
      Linus Torvalds authored
      commit 38f7bd94 upstream.
      
      This reverts commit c845acb3.
      
      It turns out that it just replaces one deadlock with another one: we can
      still get the wrong lock ordering with the readlock due to overlayfs
      calling back into the filesystem layer and still taking the vfs locks
      after the readlock.
      
      The proper solution ends up being to just split the readlock into two
      pieces: the bind lock (taken *outside* the vfs locks) and the IO lock
      (taken *inside* the filesystem locks).  The two locks are independent
      anyway.
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Reviewed-by: default avatarShmulik Ladkani <shmulik.ladkani@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9547c9a2
  2. 08 Feb, 2017 33 commits