1. 13 Aug, 2017 18 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.9.43 · 6da35f43
      Greg Kroah-Hartman authored
      6da35f43
    • Greg Kroah-Hartman's avatar
      Revert "ARM: dts: sun8i: Support DTB build for NanoPi M1" · 1166e3e0
      Greg Kroah-Hartman authored
      This reverts commit 1e9e7178 which is
      commit 661ccdc1 upstream.
      
      It's not needed in 4.9, and it breaks the build.
      Reported-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Cc: Milo Kim <woogyom.kim@gmail.com>
      Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
      Cc: Sasha Levin <alexander.levin@verizon.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1166e3e0
    • Suzuki K Poulose's avatar
      KVM: arm/arm64: Handle hva aging while destroying the vm · 3f0075cd
      Suzuki K Poulose authored
      commit 7e5a6722 upstream.
      
      The mmu_notifier_release() callback of KVM triggers cleaning up
      the stage2 page table on kvm-arm. However there could be other
      notifier callbacks in parallel with the mmu_notifier_release(),
      which could cause the call backs ending up in an empty stage2
      page table. Make sure we check it for all the notifier callbacks.
      
      Fixes: commit 293f2936 ("kvm-arm: Unmap shadow pagetables properly")
      Reported-by: default avatarAlex Graf <agraf@suse.de>
      Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
      Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      
      3f0075cd
    • Rob Gardner's avatar
      sparc64: Prevent perf from running during super critical sections · 6309eb77
      Rob Gardner authored
      commit fc290a11 upstream.
      
      This fixes another cause of random segfaults and bus errors that may
      occur while running perf with the callgraph option.
      
      Critical sections beginning with spin_lock_irqsave() raise the interrupt
      level to PIL_NORMAL_MAX (14) and intentionally do not block performance
      counter interrupts, which arrive at PIL_NMI (15).
      
      But some sections of code are "super critical" with respect to perf
      because the perf_callchain_user() path accesses user space and may cause
      TLB activity as well as faults as it unwinds the user stack.
      
      One particular critical section occurs in switch_mm:
      
              spin_lock_irqsave(&mm->context.lock, flags);
              ...
              load_secondary_context(mm);
              tsb_context_switch(mm);
              ...
              spin_unlock_irqrestore(&mm->context.lock, flags);
      
      If a perf interrupt arrives in between load_secondary_context() and
      tsb_context_switch(), then perf_callchain_user() could execute with
      the context ID of one process, but with an active TSB for a different
      process. When the user stack is accessed, it is very likely to
      incur a TLB miss, since the h/w context ID has been changed. The TLB
      will then be reloaded with a translation from the TSB for one process,
      but using a context ID for another process. This exposes memory from
      one process to another, and since it is a mapping for stack memory,
      this usually causes the new process to crash quickly.
      
      This super critical section needs more protection than is provided
      by spin_lock_irqsave() since perf interrupts must not be allowed in.
      
      Since __tsb_context_switch already goes through the trouble of
      disabling interrupts completely, we fix this by moving the secondary
      context load down into this better protected region.
      
      Orabug: 25577560
      Signed-off-by: default avatarDave Aldridge <david.j.aldridge@oracle.com>
      Signed-off-by: default avatarRob Gardner <rob.gardner@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6309eb77
    • Willem de Bruijn's avatar
      udp: consistently apply ufo or fragmentation · 33dc6a6a
      Willem de Bruijn authored
      
      [ Upstream commit 85f1bd9a ]
      
      When iteratively building a UDP datagram with MSG_MORE and that
      datagram exceeds MTU, consistently choose UFO or fragmentation.
      
      Once skb_is_gso, always apply ufo. Conversely, once a datagram is
      split across multiple skbs, do not consider ufo.
      
      Sendpage already maintains the first invariant, only add the second.
      IPv6 does not have a sendpage implementation to modify.
      
      A gso skb must have a partial checksum, do not follow sk_no_check_tx
      in udp_send_skb.
      
      Found by syzkaller.
      
      Fixes: e89e9cf5 ("[IPv4/IPv6]: UFO Scatter-gather approach")
      Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Signed-off-by: default avatarWillem 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>
      33dc6a6a
    • Greg Kroah-Hartman's avatar
      revert "ipv4: Should use consistent conditional judgement for ip fragment in... · 4688f042
      Greg Kroah-Hartman authored
      revert "ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish_output"
      
      This reverts commit f102bb71 which is
      commit 0a28cfd5 upstream as there is
      another patch that needs to be applied instead of this one.
      
      Cc: Zheng Li <james.z.li@ericsson.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Sasha Levin <alexander.levin@verizon.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      
      4688f042
    • Greg Kroah-Hartman's avatar
      revert "net: account for current skb length when deciding about UFO" · 53eed8aa
      Greg Kroah-Hartman authored
      This reverts commit ef09c9ff which is
      commit a5cb659b upstream as it causes
      merge issues with later patches that are much more important...
      
      Cc: Michal Kubecek <mkubecek@suse.cz>
      Cc: Vlad Yasevich <vyasevic@redhat.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Sasha Levin <alexander.levin@verizon.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      53eed8aa
    • Willem de Bruijn's avatar
      packet: fix tp_reserve race in packet_set_ring · e5841355
      Willem de Bruijn authored
      
      [ Upstream commit c27927e3 ]
      
      Updates to tp_reserve can race with reads of the field in
      packet_set_ring. Avoid this by holding the socket lock during
      updates in setsockopt PACKET_RESERVE.
      
      This bug was discovered by syzkaller.
      
      Fixes: 8913336a ("packet: add PACKET_RESERVE sockopt")
      Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Signed-off-by: default avatarWillem 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>
      e5841355
    • Nikolay Borisov's avatar
      igmp: Fix regression caused by igmp sysctl namespace code. · f628c9df
      Nikolay Borisov authored
      
      [ Upstream commit 1714020e ]
      
      Commit dcd87999 ("igmp: net: Move igmp namespace init to correct file")
      moved the igmp sysctls initialization from tcp_sk_init to igmp_net_init. This
      function is only called as part of per-namespace initialization, only if
      CONFIG_IP_MULTICAST is defined, otherwise igmp_mc_init() call in ip_init is
      compiled out, casuing the igmp pernet ops to not be registerd and those sysctl
      being left initialized with 0. However, there are certain functions, such as
      ip_mc_join_group which are always compiled and make use of some of those
      sysctls. Let's do a partial revert of the aforementioned commit and move the
      sysctl initialization into inet_init_net, that way they will always have
      sane values.
      
      Fixes: dcd87999 ("igmp: net: Move igmp namespace init to correct file")
      Link: https://bugzilla.kernel.org/show_bug.cgi?id=196595Reported-by: default avatarGerardo Exequiel Pozzi <vmlinuz386@gmail.com>
      Signed-off-by: default avatarNikolay Borisov <nborisov@suse.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f628c9df
    • Willem de Bruijn's avatar
      net: avoid skb_warn_bad_offload false positives on UFO · 69ffc964
      Willem de Bruijn authored
      
      [ Upstream commit 8d63bee6 ]
      
      skb_warn_bad_offload triggers a warning when an skb enters the GSO
      stack at __skb_gso_segment that does not have CHECKSUM_PARTIAL
      checksum offload set.
      
      Commit b2504a5d ("net: reduce skb_warn_bad_offload() noise")
      observed that SKB_GSO_DODGY producers can trigger the check and
      that passing those packets through the GSO handlers will fix it
      up. But, the software UFO handler will set ip_summed to
      CHECKSUM_NONE.
      
      When __skb_gso_segment is called from the receive path, this
      triggers the warning again.
      
      Make UFO set CHECKSUM_UNNECESSARY instead of CHECKSUM_NONE. On
      Tx these two are equivalent. On Rx, this better matches the
      skb state (checksum computed), as CHECKSUM_NONE here means no
      checksum computed.
      
      See also this thread for context:
      http://patchwork.ozlabs.org/patch/799015/
      
      Fixes: b2504a5d ("net: reduce skb_warn_bad_offload() noise")
      Signed-off-by: default avatarWillem 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>
      69ffc964
    • Eric Dumazet's avatar
      tcp: fastopen: tcp_connect() must refresh the route · 87fdcfe2
      Eric Dumazet authored
      
      [ Upstream commit 8ba60924 ]
      
      With new TCP_FASTOPEN_CONNECT socket option, there is a possibility
      to call tcp_connect() while socket sk_dst_cache is either NULL
      or invalid.
      
       +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 4
       +0 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0
       +0 setsockopt(4, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0
       +0 connect(4, ..., ...) = 0
      
      << sk->sk_dst_cache becomes obsolete, or even set to NULL >>
      
       +1 sendto(4, ..., 1000, MSG_FASTOPEN, ..., ...) = 1000
      
      We need to refresh the route otherwise bad things can happen,
      especially when syzkaller is running on the host :/
      
      Fixes: 19f6d3f3 ("net/tcp-fastopen: Add new API support")
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Cc: Wei Wang <weiwan@google.com>
      Cc: Yuchung Cheng <ycheng@google.com>
      Acked-by: default avatarWei Wang <weiwan@google.com>
      Acked-by: default avatarYuchung Cheng <ycheng@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      87fdcfe2
    • Xin Long's avatar
      net: sched: set xt_tgchk_param par.nft_compat as 0 in ipt_init_target · e392e305
      Xin Long authored
      
      [ Upstream commit 96d97030 ]
      
      Commit 55917a21 ("netfilter: x_tables: add context to know if
      extension runs from nft_compat") introduced a member nft_compat to
      xt_tgchk_param structure.
      
      But it didn't set it's value for ipt_init_target. With unexpected
      value in par.nft_compat, it may return unexpected result in some
      target's checkentry.
      
      This patch is to set all it's fields as 0 and only initialize the
      non-zero fields in ipt_init_target.
      
      v1->v2:
        As Wang Cong's suggestion, fix it by setting all it's fields as
        0 and only initializing the non-zero fields.
      
      Fixes: 55917a21 ("netfilter: x_tables: add context to know if extension runs from nft_compat")
      Suggested-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
      Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e392e305
    • Davide Caratti's avatar
      net/mlx4_en: don't set CHECKSUM_COMPLETE on SCTP packets · 35d90144
      Davide Caratti authored
      
      [ Upstream commit e718fe45 ]
      
      if the NIC fails to validate the checksum on TCP/UDP, and validation of IP
      checksum is successful, the driver subtracts the pseudo-header checksum
      from the value obtained by the hardware and sets CHECKSUM_COMPLETE. Don't
      do that if protocol is IPPROTO_SCTP, otherwise CRC32c validation fails.
      
      V2: don't test MLX4_CQE_STATUS_IPV6 if MLX4_CQE_STATUS_IPV4 is set
      Reported-by: default avatarShuang Li <shuali@redhat.com>
      Fixes: f8c6455b ("net/mlx4_en: Extend checksum offloading by CHECKSUM COMPLETE")
      Signed-off-by: default avatarDavide Caratti <dcaratti@redhat.com>
      Acked-by: default avatarSaeed Mahameed <saeedm@mellanox.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      35d90144
    • Daniel Borkmann's avatar
      bpf, s390: fix jit branch offset related to ldimm64 · 1b582a2c
      Daniel Borkmann authored
      
      [ Upstream commit b0a0c256 ]
      
      While testing some other work that required JIT modifications, I
      run into test_bpf causing a hang when JIT enabled on s390. The
      problematic test case was the one from ddc665a4 (bpf, arm64:
      fix jit branch offset related to ldimm64), and turns out that we
      do have a similar issue on s390 as well. In bpf_jit_prog() we
      update next instruction address after returning from bpf_jit_insn()
      with an insn_count. bpf_jit_insn() returns either -1 in case of
      error (e.g. unsupported insn), 1 or 2. The latter is only the
      case for ldimm64 due to spanning 2 insns, however, next address
      is only set to i + 1 not taking actual insn_count into account,
      thus fix is to use insn_count instead of 1. bpf_jit_enable in
      mode 2 provides also disasm on s390:
      
      Before fix:
      
        000003ff800349b6: a7f40003   brc     15,3ff800349bc                 ; target
        000003ff800349ba: 0000               unknown
        000003ff800349bc: e3b0f0700024       stg     %r11,112(%r15)
        000003ff800349c2: e3e0f0880024       stg     %r14,136(%r15)
        000003ff800349c8: 0db0               basr    %r11,%r0
        000003ff800349ca: c0ef00000000       llilf   %r14,0
        000003ff800349d0: e320b0360004       lg      %r2,54(%r11)
        000003ff800349d6: e330b03e0004       lg      %r3,62(%r11)
        000003ff800349dc: ec23ffeda065       clgrj   %r2,%r3,10,3ff800349b6 ; jmp
        000003ff800349e2: e3e0b0460004       lg      %r14,70(%r11)
        000003ff800349e8: e3e0b04e0004       lg      %r14,78(%r11)
        000003ff800349ee: b904002e   lgr     %r2,%r14
        000003ff800349f2: e3b0f0700004       lg      %r11,112(%r15)
        000003ff800349f8: e3e0f0880004       lg      %r14,136(%r15)
        000003ff800349fe: 07fe               bcr     15,%r14
      
      After fix:
      
        000003ff80ef3db4: a7f40003   brc     15,3ff80ef3dba
        000003ff80ef3db8: 0000               unknown
        000003ff80ef3dba: e3b0f0700024       stg     %r11,112(%r15)
        000003ff80ef3dc0: e3e0f0880024       stg     %r14,136(%r15)
        000003ff80ef3dc6: 0db0               basr    %r11,%r0
        000003ff80ef3dc8: c0ef00000000       llilf   %r14,0
        000003ff80ef3dce: e320b0360004       lg      %r2,54(%r11)
        000003ff80ef3dd4: e330b03e0004       lg      %r3,62(%r11)
        000003ff80ef3dda: ec230006a065       clgrj   %r2,%r3,10,3ff80ef3de6 ; jmp
        000003ff80ef3de0: e3e0b0460004       lg      %r14,70(%r11)
        000003ff80ef3de6: e3e0b04e0004       lg      %r14,78(%r11)          ; target
        000003ff80ef3dec: b904002e   lgr     %r2,%r14
        000003ff80ef3df0: e3b0f0700004       lg      %r11,112(%r15)
        000003ff80ef3df6: e3e0f0880004       lg      %r14,136(%r15)
        000003ff80ef3dfc: 07fe               bcr     15,%r14
      
      test_bpf.ko suite runs fine after the fix.
      
      Fixes: 05462310 ("s390/bpf: Add s390x eBPF JIT compiler backend")
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Tested-by: default avatarMichael Holzheu <holzheu@linux.vnet.ibm.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1b582a2c
    • Eric Dumazet's avatar
      net: fix keepalive code vs TCP_FASTOPEN_CONNECT · 05046af3
      Eric Dumazet authored
      
      [ Upstream commit 2dda6400 ]
      
      syzkaller was able to trigger a divide by 0 in TCP stack [1]
      
      Issue here is that keepalive timer needs to be updated to not attempt
      to send a probe if the connection setup was deferred using
      TCP_FASTOPEN_CONNECT socket option added in linux-4.11
      
      [1]
       divide error: 0000 [#1] SMP
       CPU: 18 PID: 0 Comm: swapper/18 Not tainted
       task: ffff986f62f4b040 ti: ffff986f62fa2000 task.ti: ffff986f62fa2000
       RIP: 0010:[<ffffffff8409cc0d>]  [<ffffffff8409cc0d>] __tcp_select_window+0x8d/0x160
       Call Trace:
        <IRQ>
        [<ffffffff8409d951>] tcp_transmit_skb+0x11/0x20
        [<ffffffff8409da21>] tcp_xmit_probe_skb+0xc1/0xe0
        [<ffffffff840a0ee8>] tcp_write_wakeup+0x68/0x160
        [<ffffffff840a151b>] tcp_keepalive_timer+0x17b/0x230
        [<ffffffff83b3f799>] call_timer_fn+0x39/0xf0
        [<ffffffff83b40797>] run_timer_softirq+0x1d7/0x280
        [<ffffffff83a04ddb>] __do_softirq+0xcb/0x257
        [<ffffffff83ae03ac>] irq_exit+0x9c/0xb0
        [<ffffffff83a04c1a>] smp_apic_timer_interrupt+0x6a/0x80
        [<ffffffff83a03eaf>] apic_timer_interrupt+0x7f/0x90
        <EOI>
        [<ffffffff83fed2ea>] ? cpuidle_enter_state+0x13a/0x3b0
        [<ffffffff83fed2cd>] ? cpuidle_enter_state+0x11d/0x3b0
      
      Tested:
      
      Following packetdrill no longer crashes the kernel
      
      `echo 0 >/proc/sys/net/ipv4/tcp_timestamps`
      
      // Cache warmup: send a Fast Open cookie request
          0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
         +0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0
         +0 setsockopt(3, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0
         +0 connect(3, ..., ...) = -1 EINPROGRESS (Operation is now in progress)
         +0 > S 0:0(0) <mss 1460,nop,nop,sackOK,nop,wscale 8,FO,nop,nop>
       +.01 < S. 123:123(0) ack 1 win 14600 <mss 1460,nop,nop,sackOK,nop,wscale 6,FO abcd1234,nop,nop>
         +0 > . 1:1(0) ack 1
         +0 close(3) = 0
         +0 > F. 1:1(0) ack 1
         +0 < F. 1:1(0) ack 2 win 92
         +0 > .  2:2(0) ack 2
      
         +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 4
         +0 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0
         +0 setsockopt(4, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0
         +0 setsockopt(4, SOL_SOCKET, SO_KEEPALIVE, [1], 4) = 0
       +.01 connect(4, ..., ...) = 0
         +0 setsockopt(4, SOL_TCP, TCP_KEEPIDLE, [5], 4) = 0
         +10 close(4) = 0
      
      `echo 1 >/proc/sys/net/ipv4/tcp_timestamps`
      
      Fixes: 19f6d3f3 ("net/tcp-fastopen: Add new API support")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: Wei Wang <weiwan@google.com>
      Cc: Yuchung Cheng <ycheng@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      05046af3
    • Yuchung Cheng's avatar
      tcp: avoid setting cwnd to invalid ssthresh after cwnd reduction states · 3914a7ec
      Yuchung Cheng authored
      
      [ Upstream commit ed254971 ]
      
      If the sender switches the congestion control during ECN-triggered
      cwnd-reduction state (CA_CWR), upon exiting recovery cwnd is set to
      the ssthresh value calculated by the previous congestion control. If
      the previous congestion control is BBR that always keep ssthresh
      to TCP_INIFINITE_SSTHRESH, cwnd ends up being infinite. The safe
      step is to avoid assigning invalid ssthresh value when recovery ends.
      Signed-off-by: default avatarYuchung Cheng <ycheng@google.com>
      Signed-off-by: default avatarNeal Cardwell <ncardwell@google.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>
      3914a7ec
    • Guillaume Nault's avatar
      ppp: fix xmit recursion detection on ppp channels · 6ec6ec3b
      Guillaume Nault authored
      
      [ Upstream commit 0a0e1a85 ]
      
      Commit e5dadc65 ("ppp: Fix false xmit recursion detect with two ppp
      devices") dropped the xmit_recursion counter incrementation in
      ppp_channel_push() and relied on ppp_xmit_process() for this task.
      But __ppp_channel_push() can also send packets directly (using the
      .start_xmit() channel callback), in which case the xmit_recursion
      counter isn't incremented anymore. If such packets get routed back to
      the parent ppp unit, ppp_xmit_process() won't notice the recursion and
      will call ppp_channel_push() on the same channel, effectively creating
      the deadlock situation that the xmit_recursion mechanism was supposed
      to prevent.
      
      This patch re-introduces the xmit_recursion counter incrementation in
      ppp_channel_push(). Since the xmit_recursion variable is now part of
      the parent ppp unit, incrementation is skipped if the channel doesn't
      have any. This is fine because only packets routed through the parent
      unit may enter the channel recursively.
      
      Finally, we have to ensure that pch->ppp is not going to be modified
      while executing ppp_channel_push(). Instead of taking this lock only
      while calling ppp_xmit_process(), we now have to hold it for the full
      ppp_channel_push() execution. This respects the ppp locks ordering
      which requires locking ->upl before ->downl.
      
      Fixes: e5dadc65 ("ppp: Fix false xmit recursion detect with two ppp devices")
      Signed-off-by: default avatarGuillaume Nault <g.nault@alphalink.fr>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6ec6ec3b
    • Gao Feng's avatar
      ppp: Fix false xmit recursion detect with two ppp devices · 3b25bfc1
      Gao Feng authored
      
      [ Upstream commit e5dadc65 ]
      
      The global percpu variable ppp_xmit_recursion is used to detect the ppp
      xmit recursion to avoid the deadlock, which is caused by one CPU tries to
      lock the xmit lock twice. But it would report false recursion when one CPU
      wants to send the skb from two different PPP devices, like one L2TP on the
      PPPoE. It is a normal case actually.
      
      Now use one percpu member of struct ppp instead of the gloable variable to
      detect the xmit recursion of one ppp device.
      
      Fixes: 55454a56 ("ppp: avoid dealock on recursive xmit")
      Signed-off-by: default avatarGao Feng <gfree.wind@vip.163.com>
      Signed-off-by: default avatarLiu Jianying <jianying.liu@ikuai8.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3b25bfc1
  2. 11 Aug, 2017 22 commits