1. 28 11月, 2020 4 次提交
  2. 27 11月, 2020 4 次提交
  3. 26 11月, 2020 12 次提交
  4. 25 11月, 2020 16 次提交
    • J
      Documentation: netdev-FAQ: suggest how to post co-dependent series · 6f7a1f9c
      Jakub Kicinski 提交于
      Make an explicit suggestion how to post user space side of kernel
      patches to avoid reposts when patchwork groups the wrong patches.
      
      v2: mention the cases unlike iproute2 explicitly
      Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
      Reviewed-by: NDavid Ahern <dsahern@kernel.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6f7a1f9c
    • J
      Merge tag 'batadv-net-pullrequest-20201124' of git://git.open-mesh.org/linux-merge · 26c89965
      Jakub Kicinski 提交于
      Simon Wunderlich says:
      
      ====================
      Here is a batman-adv bugfix:
      
       - set module owner to THIS_MODULE, by Taehee Yoo
      
      * tag 'batadv-net-pullrequest-20201124' of git://git.open-mesh.org/linux-merge:
        batman-adv: set .owner to THIS_MODULE
      ====================
      
      Link: https://lore.kernel.org/r/20201124134417.17269-1-sw@simonwunderlich.deSigned-off-by: NJakub Kicinski <kuba@kernel.org>
      26c89965
    • J
      Merge branch 'ibmvnic-null-pointer-dereference' · 49d66ed8
      Jakub Kicinski 提交于
      Lijun Pan says:
      
      ====================
      ibmvnic: null pointer dereference
      
      Fix two NULL pointer dereference crash issues.
      Improve module removal procedure.
      ====================
      
      Link: https://lore.kernel.org/r/20201123193547.57225-1-ljp@linux.ibm.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>
      49d66ed8
    • L
      ibmvnic: enhance resetting status check during module exit · 3ada2881
      Lijun Pan 提交于
      Based on the discussion with Sukadev Bhattiprolu and Dany Madden,
      we believe that checking adapter->resetting bit is preferred
      since RESETTING state flag is not as strict as resetting bit.
      RESETTING state flag is removed since it is verbose now.
      
      Fixes: 7d7195a0 ("ibmvnic: Do not process device remove during device reset")
      Signed-off-by: NLijun Pan <ljp@linux.ibm.com>
      Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      3ada2881
    • L
      ibmvnic: fix NULL pointer dereference in ibmvic_reset_crq · 0e435bef
      Lijun Pan 提交于
      crq->msgs could be NULL if the previous reset did not complete after
      freeing crq->msgs. Check for NULL before dereferencing them.
      
      Snippet of call trace:
      ...
      ibmvnic 30000003 env3 (unregistering): Releasing sub-CRQ
      ibmvnic 30000003 env3 (unregistering): Releasing CRQ
      BUG: Kernel NULL pointer dereference on read at 0x00000000
      Faulting instruction address: 0xc0000000000c1a30
      Oops: Kernel access of bad area, sig: 11 [#1]
      LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
      Modules linked in: ibmvnic(E-) rpadlpar_io rpaphp xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 nft_compat nft_counter nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables xsk_diag tcp_diag udp_diag tun raw_diag inet_diag unix_diag bridge af_packet_diag netlink_diag stp llc rfkill sunrpc pseries_rng xts vmx_crypto uio_pdrv_genirq uio binfmt_misc ip_tables xfs libcrc32c sd_mod t10_pi sg ibmvscsi ibmveth scsi_transport_srp dm_mirror dm_region_hash dm_log dm_mod [last unloaded: ibmvnic]
      CPU: 20 PID: 8426 Comm: kworker/20:0 Tainted: G            E     5.10.0-rc1+ #12
      Workqueue: events __ibmvnic_reset [ibmvnic]
      NIP:  c0000000000c1a30 LR: c008000001b00c18 CTR: 0000000000000400
      REGS: c00000000d05b7a0 TRAP: 0380   Tainted: G            E      (5.10.0-rc1+)
      MSR:  800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 44002480  XER: 20040000
      CFAR: c0000000000c19ec IRQMASK: 0
      GPR00: 0000000000000400 c00000000d05ba30 c008000001b17c00 0000000000000000
      GPR04: 0000000000000000 0000000000000000 0000000000000000 00000000000001e2
      GPR08: 000000000001f400 ffffffffffffd950 0000000000000000 c008000001b0b280
      GPR12: c0000000000c19c8 c00000001ec72e00 c00000000019a778 c00000002647b440
      GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
      GPR20: 0000000000000006 0000000000000001 0000000000000003 0000000000000002
      GPR24: 0000000000001000 c008000001b0d570 0000000000000005 c00000007ab5d550
      GPR28: c00000007ab5c000 c000000032fcf848 c00000007ab5cc00 c000000032fcf800
      NIP [c0000000000c1a30] memset+0x68/0x104
      LR [c008000001b00c18] ibmvnic_reset_crq+0x70/0x110 [ibmvnic]
      Call Trace:
      [c00000000d05ba30] [0000000000000800] 0x800 (unreliable)
      [c00000000d05bab0] [c008000001b0a930] do_reset.isra.40+0x224/0x634 [ibmvnic]
      [c00000000d05bb80] [c008000001b08574] __ibmvnic_reset+0x17c/0x3c0 [ibmvnic]
      [c00000000d05bc50] [c00000000018d9ac] process_one_work+0x2cc/0x800
      [c00000000d05bd20] [c00000000018df58] worker_thread+0x78/0x520
      [c00000000d05bdb0] [c00000000019a934] kthread+0x1c4/0x1d0
      [c00000000d05be20] [c00000000000d5d0] ret_from_kernel_thread+0x5c/0x6c
      
      Fixes: 032c5e82 ("Driver for IBM System i/p VNIC protocol")
      Signed-off-by: NLijun Pan <ljp@linux.ibm.com>
      Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      0e435bef
    • L
      ibmvnic: fix NULL pointer dereference in reset_sub_crq_queues · a0faaa27
      Lijun Pan 提交于
      adapter->tx_scrq and adapter->rx_scrq could be NULL if the previous reset
      did not complete after freeing sub crqs. Check for NULL before
      dereferencing them.
      
      Snippet of call trace:
      ibmvnic 30000006 env6: Releasing sub-CRQ
      ibmvnic 30000006 env6: Releasing CRQ
      ...
      ibmvnic 30000006 env6: Got Control IP offload Response
      ibmvnic 30000006 env6: Re-setting tx_scrq[0]
      BUG: Kernel NULL pointer dereference on read at 0x00000000
      Faulting instruction address: 0xc008000003dea7cc
      Oops: Kernel access of bad area, sig: 11 [#1]
      LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
      Modules linked in: rpadlpar_io rpaphp xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 nft_compat nft_counter nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables xsk_diag tcp_diag udp_diag raw_diag inet_diag unix_diag af_packet_diag netlink_diag tun bridge stp llc rfkill sunrpc pseries_rng xts vmx_crypto uio_pdrv_genirq uio binfmt_misc ip_tables xfs libcrc32c sd_mod t10_pi sg ibmvscsi ibmvnic ibmveth scsi_transport_srp dm_mirror dm_region_hash dm_log dm_mod
      CPU: 80 PID: 1856 Comm: kworker/80:2 Tainted: G        W         5.8.0+ #4
      Workqueue: events __ibmvnic_reset [ibmvnic]
      NIP:  c008000003dea7cc LR: c008000003dea7bc CTR: 0000000000000000
      REGS: c0000007ef7db860 TRAP: 0380   Tainted: G        W          (5.8.0+)
      MSR:  800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 28002422  XER: 0000000d
      CFAR: c000000000bd9520 IRQMASK: 0
      GPR00: c008000003dea7bc c0000007ef7dbaf0 c008000003df7400 c0000007fa26ec00
      GPR04: c0000007fcd0d008 c0000007fcd96350 0000000000000027 c0000007fcd0d010
      GPR08: 0000000000000023 0000000000000000 0000000000000000 0000000000000000
      GPR12: 0000000000002000 c00000001ec18e00 c0000000001982f8 c0000007bad6e840
      GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
      GPR20: 0000000000000000 0000000000000000 0000000000000000 fffffffffffffef7
      GPR24: 0000000000000402 c0000007fa26f3a8 0000000000000003 c00000016f8ec048
      GPR28: 0000000000000000 0000000000000000 0000000000000000 c0000007fa26ec00
      NIP [c008000003dea7cc] ibmvnic_reset_init+0x15c/0x258 [ibmvnic]
      LR [c008000003dea7bc] ibmvnic_reset_init+0x14c/0x258 [ibmvnic]
      Call Trace:
      [c0000007ef7dbaf0] [c008000003dea7bc] ibmvnic_reset_init+0x14c/0x258 [ibmvnic] (unreliable)
      [c0000007ef7dbb80] [c008000003de8860] __ibmvnic_reset+0x408/0x970 [ibmvnic]
      [c0000007ef7dbc50] [c00000000018b7cc] process_one_work+0x2cc/0x800
      [c0000007ef7dbd20] [c00000000018bd78] worker_thread+0x78/0x520
      [c0000007ef7dbdb0] [c0000000001984c4] kthread+0x1d4/0x1e0
      [c0000007ef7dbe20] [c00000000000cea8] ret_from_kernel_thread+0x5c/0x74
      
      Fixes: 57a49436 ("ibmvnic: Reset sub-crqs during driver reset")
      Signed-off-by: NLijun Pan <ljp@linux.ibm.com>
      Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      a0faaa27
    • J
      Merge branch 'fixes-for-ena-driver' · 5fc145f1
      Jakub Kicinski 提交于
      Shay Agroskin says:
      
      ====================
      Fixes for ENA driver
      
      - fix wrong data offset on machines that support rx offset
      - work-around Intel iommu issue
      - fix out of bound access when request id is wrong
      ====================
      
      Link: https://lore.kernel.org/r/20201123190859.21298-1-shayagr@amazon.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>
      5fc145f1
    • S
      net: ena: fix packet's addresses for rx_offset feature · 1396d314
      Shay Agroskin 提交于
      This patch fixes two lines in which the rx_offset received by the device
      wasn't taken into account:
      
      - prefetch function:
      	In our driver the copied data would reside in
      	rx_info->page + rx_headroom + rx_offset
      
      	so the prefetch function is changed accordingly.
      
      - setting page_offset to zero for descriptors > 1:
      	for every descriptor but the first, the rx_offset is zero. Hence
      	the page_offset value should be set to rx_headroom.
      
      	The previous implementation changed the value of rx_info after
      	the descriptor was added to the SKB (essentially providing wrong
      	page offset).
      
      Fixes: 68f236df ("net: ena: add support for the rx offset feature")
      Signed-off-by: NShay Agroskin <shayagr@amazon.com>
      Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      1396d314
    • S
      net: ena: set initial DMA width to avoid intel iommu issue · 09323b3b
      Shay Agroskin 提交于
      The ENA driver uses the readless mechanism, which uses DMA, to find
      out what the DMA mask is supposed to be.
      
      If DMA is used without setting the dma_mask first, it causes the
      Intel IOMMU driver to think that ENA is a 32-bit device and therefore
      disables IOMMU passthrough permanently.
      
      This patch sets the dma_mask to be ENA_MAX_PHYS_ADDR_SIZE_BITS=48
      before readless initialization in
      ena_device_init()->ena_com_mmio_reg_read_request_init(),
      which is large enough to workaround the intel_iommu issue.
      
      DMA mask is set again to the correct value after it's received from the
      device after readless is initialized.
      
      The patch also changes the driver to use dma_set_mask_and_coherent()
      function instead of the two pci_set_dma_mask() and
      pci_set_consistent_dma_mask() ones. Both methods achieve the same
      effect.
      
      Fixes: 1738cd3e ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)")
      Signed-off-by: NMike Cui <mikecui@amazon.com>
      Signed-off-by: NArthur Kiyanovski <akiyano@amazon.com>
      Signed-off-by: NShay Agroskin <shayagr@amazon.com>
      Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      09323b3b
    • S
      net: ena: handle bad request id in ena_netdev · 5b7022cf
      Shay Agroskin 提交于
      After request id is checked in validate_rx_req_id() its value is still
      used in the line
      	rx_ring->free_ids[next_to_clean] =
      					rx_ring->ena_bufs[i].req_id;
      even if it was found to be out-of-bound for the array free_ids.
      
      The patch moves the request id to an earlier stage in the napi routine and
      makes sure its value isn't used if it's found out-of-bounds.
      
      Fixes: 30623e1e ("net: ena: avoid memory access violation by validating req_id properly")
      Signed-off-by: NIdo Segev <idose@amazon.com>
      Signed-off-by: NShay Agroskin <shayagr@amazon.com>
      Signed-off-by: NJakub Kicinski <kuba@kernel.org>
      5b7022cf
    • K
      nfc: s3fwrn5: use signed integer for parsing GPIO numbers · d8f0a867
      Krzysztof Kozlowski 提交于
      GPIOs - as returned by of_get_named_gpio() and used by the gpiolib - are
      signed integers, where negative number indicates error.  The return
      value of of_get_named_gpio() should not be assigned to an unsigned int
      because in case of !CONFIG_GPIOLIB such number would be a valid GPIO.
      
      Fixes: c04c674f ("nfc: s3fwrn5: Add driver for Samsung S3FWRN5 NFC Chip")
      Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
      Link: https://lore.kernel.org/r/20201123162351.209100-1-krzk@kernel.orgSigned-off-by: NJakub Kicinski <kuba@kernel.org>
      d8f0a867
    • E
      dpaa2-eth: Fix compile error due to missing devlink support · 078eb55c
      Ezequiel Garcia 提交于
      The dpaa2 driver depends on devlink, so it should select
      NET_DEVLINK in order to fix compile errors, such as:
      
      drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.o: in function `dpaa2_eth_rx_err':
      dpaa2-eth.c:(.text+0x3cec): undefined reference to `devlink_trap_report'
      drivers/net/ethernet/freescale/dpaa2/dpaa2-eth-devlink.o: in function `dpaa2_eth_dl_info_get':
      dpaa2-eth-devlink.c:(.text+0x160): undefined reference to `devlink_info_driver_name_put'
      
      Fixes: ceeb03ad ("dpaa2-eth: add basic devlink support")
      Signed-off-by: NEzequiel Garcia <ezequiel@collabora.com>
      Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
      Link: https://lore.kernel.org/r/20201123163553.1666476-1-ciorneiioana@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>
      078eb55c
    • J
    • A
      tcp: Set ECT0 bit in tos/tclass for synack when BPF needs ECN · 407c85c7
      Alexander Duyck 提交于
      When a BPF program is used to select between a type of TCP congestion
      control algorithm that uses either ECN or not there is a case where the
      synack for the frame was coming up without the ECT0 bit set. A bit of
      research found that this was due to the final socket being configured to
      dctcp while the listener socket was staying in cubic.
      
      To reproduce it all that is needed is to monitor TCP traffic while running
      the sample bpf program "samples/bpf/tcp_cong_kern.c". What is observed,
      assuming tcp_dctcp module is loaded or compiled in and the traffic matches
      the rules in the sample file, is that for all frames with the exception of
      the synack the ECT0 bit is set.
      
      To address that it is necessary to make one additional call to
      tcp_bpf_ca_needs_ecn using the request socket and then use the output of
      that to set the ECT0 bit for the tos/tclass of the packet.
      
      Fixes: 91b5b21c ("bpf: Add support for changing congestion control")
      Signed-off-by: NAlexander Duyck <alexanderduyck@fb.com>
      Link: https://lore.kernel.org/r/160593039663.2604.1374502006916871573.stgit@localhost.localdomainSigned-off-by: NJakub Kicinski <kuba@kernel.org>
      407c85c7
    • M
      devlink: Fix reload stats structure · 5204bb68
      Moshe Shemesh 提交于
      Fix reload stats structure exposed to the user. Change stats structure
      hierarchy to have the reload action as a parent of the stat entry and
      then stat entry includes value per limit. This will also help to avoid
      string concatenation on iproute2 output.
      
      Reload stats structure before this fix:
      "stats": {
          "reload": {
              "driver_reinit": 2,
              "fw_activate": 1,
              "fw_activate_no_reset": 0
           }
      }
      
      After this fix:
      "stats": {
          "reload": {
              "driver_reinit": {
                  "unspecified": 2
              },
              "fw_activate": {
                  "unspecified": 1,
                  "no_reset": 0
              }
      }
      
      Fixes: a254c264 ("devlink: Add reload stats")
      Signed-off-by: NMoshe Shemesh <moshe@mellanox.com>
      Reviewed-by: NJiri Pirko <jiri@nvidia.com>
      Link: https://lore.kernel.org/r/1606109785-25197-1-git-send-email-moshe@mellanox.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>
      5204bb68
    • L
      aquantia: Remove the build_skb path · 9bd2702d
      Lincoln Ramsay 提交于
      When performing IPv6 forwarding, there is an expectation that SKBs
      will have some headroom. When forwarding a packet from the aquantia
      driver, this does not always happen, triggering a kernel warning.
      
      aq_ring.c has this code (edited slightly for brevity):
      
      if (buff->is_eop && buff->len <= AQ_CFG_RX_FRAME_MAX - AQ_SKB_ALIGN) {
          skb = build_skb(aq_buf_vaddr(&buff->rxdata), AQ_CFG_RX_FRAME_MAX);
      } else {
          skb = napi_alloc_skb(napi, AQ_CFG_RX_HDR_SIZE);
      
      There is a significant difference between the SKB produced by these
      2 code paths. When napi_alloc_skb creates an SKB, there is a certain
      amount of headroom reserved. However, this is not done in the
      build_skb codepath.
      
      As the hardware buffer that build_skb is built around does not
      handle the presence of the SKB header, this code path is being
      removed and the napi_alloc_skb path will always be used. This code
      path does have to copy the packet header into the SKB, but it adds
      the packet data as a frag.
      
      Fixes: 018423e9 ("net: ethernet: aquantia: Add ring support code")
      Signed-off-by: NLincoln Ramsay <lincoln.ramsay@opengear.com>
      Link: https://lore.kernel.org/r/MWHPR1001MB23184F3EAFA413E0D1910EC9E8FC0@MWHPR1001MB2318.namprd10.prod.outlook.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>
      9bd2702d
  5. 24 11月, 2020 4 次提交
    • E
      net/packet: fix packet receive on L3 devices without visible hard header · d5496990
      Eyal Birger 提交于
      In the patchset merged by commit b9fcf0a0
      ("Merge branch 'support-AF_PACKET-for-layer-3-devices'") L3 devices which
      did not have header_ops were given one for the purpose of protocol parsing
      on af_packet transmit path.
      
      That change made af_packet receive path regard these devices as having a
      visible L3 header and therefore aligned incoming skb->data to point to the
      skb's mac_header. Some devices, such as ipip, xfrmi, and others, do not
      reset their mac_header prior to ingress and therefore their incoming
      packets became malformed.
      
      Ideally these devices would reset their mac headers, or af_packet would be
      able to rely on dev->hard_header_len being 0 for such cases, but it seems
      this is not the case.
      
      Fix by changing af_packet RX ll visibility criteria to include the
      existence of a '.create()' header operation, which is used when creating
      a device hard header - via dev_hard_header() - by upper layers, and does
      not exist in these L3 devices.
      
      As this predicate may be useful in other situations, add it as a common
      dev_has_header() helper in netdevice.h.
      
      Fixes: b9fcf0a0 ("Merge branch 'support-AF_PACKET-for-layer-3-devices'")
      Signed-off-by: NEyal Birger <eyal.birger@gmail.com>
      Acked-by: NJason A. Donenfeld <Jason@zx2c4.com>
      Acked-by: NWillem de Bruijn <willemb@google.com>
      Link: https://lore.kernel.org/r/20201121062817.3178900-1-eyal.birger@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>
      d5496990
    • S
      i40e: Fix removing driver while bare-metal VFs pass traffic · 2980cbd4
      Sylwester Dziedziuch 提交于
      Prevent VFs from resetting when PF driver is being unloaded:
      - introduce new pf state: __I40E_VF_RESETS_DISABLED;
      - check if pf state has __I40E_VF_RESETS_DISABLED state set,
        if so, disable any further VFLR event notifications;
      - when i40e_remove (rmmod i40e) is called, disable any resets on
        the VFs;
      
      Previously if there were bare-metal VFs passing traffic and PF
      driver was removed, there was a possibility of VFs triggering a Tx
      timeout right before iavf_remove. This was causing iavf_close to
      not be called because there is a check in the beginning of  iavf_remove
      that bails out early if adapter->state < IAVF_DOWN_PENDING. This
      makes it so some resources do not get cleaned up.
      
      Fixes: 6a9ddb36 ("i40e: disable IOV before freeing resources")
      Signed-off-by: NSlawomir Laba <slawomirx.laba@intel.com>
      Signed-off-by: NBrett Creeley <brett.creeley@intel.com>
      Signed-off-by: NSylwester Dziedziuch <sylwesterx.dziedziuch@intel.com>
      Tested-by: NKonrad Jankowski <konrad0.jankowski@intel.com>
      Signed-off-by: NTony Nguyen <anthony.l.nguyen@intel.com>
      Link: https://lore.kernel.org/r/20201120180640.3654474-1-anthony.l.nguyen@intel.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>
      2980cbd4
    • S
      vsock/virtio: discard packets only when socket is really closed · 3fe356d5
      Stefano Garzarella 提交于
      Starting from commit 8692cefc ("virtio_vsock: Fix race condition
      in virtio_transport_recv_pkt"), we discard packets in
      virtio_transport_recv_pkt() if the socket has been released.
      
      When the socket is connected, we schedule a delayed work to wait the
      RST packet from the other peer, also if SHUTDOWN_MASK is set in
      sk->sk_shutdown.
      This is done to complete the virtio-vsock shutdown algorithm, releasing
      the port assigned to the socket definitively only when the other peer
      has consumed all the packets.
      
      If we discard the RST packet received, the socket will be closed only
      when the VSOCK_CLOSE_TIMEOUT is reached.
      
      Sergio discovered the issue while running ab(1) HTTP benchmark using
      libkrun [1] and observing a latency increase with that commit.
      
      To avoid this issue, we discard packet only if the socket is really
      closed (SOCK_DONE flag is set).
      We also set SOCK_DONE in virtio_transport_release() when we don't need
      to wait any packets from the other peer (we didn't schedule the delayed
      work). In this case we remove the socket from the vsock lists, releasing
      the port assigned.
      
      [1] https://github.com/containers/libkrun
      
      Fixes: 8692cefc ("virtio_vsock: Fix race condition in virtio_transport_recv_pkt")
      Cc: justin.he@arm.com
      Reported-by: NSergio Lopez <slp@redhat.com>
      Tested-by: NSergio Lopez <slp@redhat.com>
      Signed-off-by: NStefano Garzarella <sgarzare@redhat.com>
      Acked-by: NJia He <justin.he@arm.com>
      Link: https://lore.kernel.org/r/20201120104736.73749-1-sgarzare@redhat.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>
      3fe356d5
    • R
      tcp: fix race condition when creating child sockets from syncookies · 01770a16
      Ricardo Dias 提交于
      When the TCP stack is in SYN flood mode, the server child socket is
      created from the SYN cookie received in a TCP packet with the ACK flag
      set.
      
      The child socket is created when the server receives the first TCP
      packet with a valid SYN cookie from the client. Usually, this packet
      corresponds to the final step of the TCP 3-way handshake, the ACK
      packet. But is also possible to receive a valid SYN cookie from the
      first TCP data packet sent by the client, and thus create a child socket
      from that SYN cookie.
      
      Since a client socket is ready to send data as soon as it receives the
      SYN+ACK packet from the server, the client can send the ACK packet (sent
      by the TCP stack code), and the first data packet (sent by the userspace
      program) almost at the same time, and thus the server will equally
      receive the two TCP packets with valid SYN cookies almost at the same
      instant.
      
      When such event happens, the TCP stack code has a race condition that
      occurs between the momement a lookup is done to the established
      connections hashtable to check for the existence of a connection for the
      same client, and the moment that the child socket is added to the
      established connections hashtable. As a consequence, this race condition
      can lead to a situation where we add two child sockets to the
      established connections hashtable and deliver two sockets to the
      userspace program to the same client.
      
      This patch fixes the race condition by checking if an existing child
      socket exists for the same client when we are adding the second child
      socket to the established connections socket. If an existing child
      socket exists, we drop the packet and discard the second child socket
      to the same client.
      Signed-off-by: NRicardo Dias <rdias@singlestore.com>
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Link: https://lore.kernel.org/r/20201120111133.GA67501@rdias-suse-pc.lanSigned-off-by: NJakub Kicinski <kuba@kernel.org>
      01770a16