1. 02 Oct, 2019 13 commits
    • Vladimir Oltean's avatar
      ptp_qoriq: Initialize the registers' spinlock before calling ptp_qoriq_settime · db34a471
      Vladimir Oltean authored
      Because ptp_qoriq_settime is being called prior to spin_lock_init, the
      following stack trace can be seen at driver probe time:
      
      [    2.269117] the code is fine but needs lockdep annotation.
      [    2.274569] turning off the locking correctness validator.
      [    2.280027] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.3.0-rc7-01478-g01eaa67a4797 #263
      [    2.288073] Hardware name: Freescale LS1021A
      [    2.292337] [<c0313cb4>] (unwind_backtrace) from [<c030e11c>] (show_stack+0x10/0x14)
      [    2.300045] [<c030e11c>] (show_stack) from [<c1219440>] (dump_stack+0xcc/0xf8)
      [    2.307235] [<c1219440>] (dump_stack) from [<c03b9b44>] (register_lock_class+0x730/0x73c)
      [    2.315372] [<c03b9b44>] (register_lock_class) from [<c03b6190>] (__lock_acquire+0x78/0x270c)
      [    2.323856] [<c03b6190>] (__lock_acquire) from [<c03b90cc>] (lock_acquire+0xe0/0x22c)
      [    2.331649] [<c03b90cc>] (lock_acquire) from [<c123c310>] (_raw_spin_lock_irqsave+0x54/0x68)
      [    2.340048] [<c123c310>] (_raw_spin_lock_irqsave) from [<c0e73fe4>] (ptp_qoriq_settime+0x38/0x80)
      [    2.348878] [<c0e73fe4>] (ptp_qoriq_settime) from [<c0e746d4>] (ptp_qoriq_init+0x1f8/0x484)
      [    2.357189] [<c0e746d4>] (ptp_qoriq_init) from [<c0e74aac>] (ptp_qoriq_probe+0xd0/0x184)
      [    2.365243] [<c0e74aac>] (ptp_qoriq_probe) from [<c0b0a07c>] (platform_drv_probe+0x48/0x9c)
      [    2.373555] [<c0b0a07c>] (platform_drv_probe) from [<c0b07a14>] (really_probe+0x1c4/0x400)
      [    2.381779] [<c0b07a14>] (really_probe) from [<c0b07e28>] (driver_probe_device+0x78/0x1b8)
      [    2.390003] [<c0b07e28>] (driver_probe_device) from [<c0b081d0>] (device_driver_attach+0x58/0x60)
      [    2.398832] [<c0b081d0>] (device_driver_attach) from [<c0b082d4>] (__driver_attach+0xfc/0x160)
      [    2.407402] [<c0b082d4>] (__driver_attach) from [<c0b05a84>] (bus_for_each_dev+0x68/0xb4)
      [    2.415539] [<c0b05a84>] (bus_for_each_dev) from [<c0b06b68>] (bus_add_driver+0x104/0x20c)
      [    2.423763] [<c0b06b68>] (bus_add_driver) from [<c0b0909c>] (driver_register+0x78/0x10c)
      [    2.431815] [<c0b0909c>] (driver_register) from [<c030313c>] (do_one_initcall+0x8c/0x3ac)
      [    2.439954] [<c030313c>] (do_one_initcall) from [<c1f013f4>] (kernel_init_freeable+0x468/0x548)
      [    2.448610] [<c1f013f4>] (kernel_init_freeable) from [<c12344d8>] (kernel_init+0x8/0x10c)
      [    2.456745] [<c12344d8>] (kernel_init) from [<c03010b4>] (ret_from_fork+0x14/0x20)
      [    2.464273] Exception stack(0xea89ffb0 to 0xea89fff8)
      [    2.469297] ffa0:                                     00000000 00000000 00000000 00000000
      [    2.477432] ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
      [    2.485566] ffe0: 00000000 00000000 00000000 00000000 00000013 00000000
      
      Fixes: ff54571a
      
       ("ptp_qoriq: convert to use ptp_qoriq_init/free")
      Signed-off-by: default avatarVladimir Oltean <olteanv@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      db34a471
    • David S. Miller's avatar
      Merge branch 'SJA1105-DSA-locking-fixes-for-PTP' · 76d67494
      David S. Miller authored
      
      
      Vladimir Oltean says:
      
      ====================
      SJA1105 DSA locking fixes for PTP
      
      This series fixes the locking API usage problems spotted when compiling
      the kernel with CONFIG_DEBUG_ATOMIC_SLEEP=y and CONFIG_DEBUG_SPINLOCK=y.
      ====================
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      76d67494
    • Vladimir Oltean's avatar
      net: dsa: sja1105: Fix sleeping while atomic in .port_hwtstamp_set · 3e8db7e5
      Vladimir Oltean authored
      Currently this stack trace can be seen with CONFIG_DEBUG_ATOMIC_SLEEP=y:
      
      [   41.568348] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:909
      [   41.576757] in_atomic(): 1, irqs_disabled(): 0, pid: 208, name: ptp4l
      [   41.583212] INFO: lockdep is turned off.
      [   41.587123] CPU: 1 PID: 208 Comm: ptp4l Not tainted 5.3.0-rc6-01445-ge950f2d4bc7f-dirty #1827
      [   41.599873] [<c0313d7c>] (unwind_backtrace) from [<c030e13c>] (show_stack+0x10/0x14)
      [   41.607584] [<c030e13c>] (show_stack) from [<c1212d50>] (dump_stack+0xd4/0x100)
      [   41.614863] [<c1212d50>] (dump_stack) from [<c037dfc8>] (___might_sleep+0x1c8/0x2b4)
      [   41.622574] [<c037dfc8>] (___might_sleep) from [<c122ea90>] (__mutex_lock+0x48/0xab8)
      [   41.630368] [<c122ea90>] (__mutex_lock) from [<c122f51c>] (mutex_lock_nested+0x1c/0x24)
      [   41.638340] [<c122f51c>] (mutex_lock_nested) from [<c0c6fe08>] (sja1105_static_config_reload+0x30/0x27c)
      [   41.647779] [<c0c6fe08>] (sja1105_static_config_reload) from [<c0c7015c>] (sja1105_hwtstamp_set+0x108/0x1cc)
      [   41.657562] [<c0c7015c>] (sja1105_hwtstamp_set) from [<c0feb650>] (dev_ifsioc+0x18c/0x330)
      [   41.665788] [<c0feb650>] (dev_ifsioc) from [<c0febbd8>] (dev_ioctl+0x320/0x6e8)
      [   41.673064] [<c0febbd8>] (dev_ioctl) from [<c0f8b1f4>] (sock_ioctl+0x334/0x5e8)
      [   41.680340] [<c0f8b1f4>] (sock_ioctl) from [<c05404a8>] (do_vfs_ioctl+0xb0/0xa10)
      [   41.687789] [<c05404a8>] (do_vfs_ioctl) from [<c0540e3c>] (ksys_ioctl+0x34/0x58)
      [   41.695151] [<c0540e3c>] (ksys_ioctl) from [<c0301000>] (ret_fast_syscall+0x0/0x28)
      [   41.702768] Exception stack(0xe8495fa8 to 0xe8495ff0)
      [   41.707796] 5fa0:                   beff4a8c 00000001 00000011 000089b0 beff4a8c beff4a80
      [   41.715933] 5fc0: beff4a8c 00000001 0000000c 00000036 b6fa98c8 004e19c1 00000001 00000000
      [   41.724069] 5fe0: 004dcedc beff4a6c 004c0738 b6e7af4c
      [   41.729860] BUG: scheduling while atomic: ptp4l/208/0x00000002
      [   41.735682] INFO: lockdep is turned off.
      
      Enabling RX timestamping will logically disturb the fastpath (processing
      of meta frames). Replace bool hwts_rx_en with a bit that is checked
      atomically from the fastpath and temporarily unset from the sleepable
      context during a change of the RX timestamping process (a destructive
      operation anyways, requires switch reset).
      If found unset, the fastpath (net/dsa/tag_sja1105.c) will just drop any
      received meta frame and not take the meta_lock at all.
      
      Fixes: a602afd2
      
       ("net: dsa: sja1105: Expose PTP timestamping ioctls to userspace")
      Signed-off-by: default avatarVladimir Oltean <olteanv@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      3e8db7e5
    • Vladimir Oltean's avatar
      net: dsa: sja1105: Initialize the meta_lock · d6530e5a
      Vladimir Oltean authored
      Otherwise, with CONFIG_DEBUG_SPINLOCK=y, this stack trace gets printed
      when enabling RX timestamping and receiving a PTP frame:
      
      [  318.537078] INFO: trying to register non-static key.
      [  318.542040] the code is fine but needs lockdep annotation.
      [  318.547500] turning off the locking correctness validator.
      [  318.552972] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-13257-g0825b0669811-dirty #1962
      [  318.561283] Hardware name: Freescale LS1021A
      [  318.565566] [<c03144bc>] (unwind_backtrace) from [<c030e164>] (show_stack+0x10/0x14)
      [  318.573289] [<c030e164>] (show_stack) from [<c11b9f50>] (dump_stack+0xd4/0x100)
      [  318.580579] [<c11b9f50>] (dump_stack) from [<c03b9b40>] (register_lock_class+0x728/0x734)
      [  318.588731] [<c03b9b40>] (register_lock_class) from [<c03b60c4>] (__lock_acquire+0x78/0x25cc)
      [  318.597227] [<c03b60c4>] (__lock_acquire) from [<c03b8ef8>] (lock_acquire+0xd8/0x234)
      [  318.605033] [<c03b8ef8>] (lock_acquire) from [<c11db934>] (_raw_spin_lock+0x44/0x54)
      [  318.612755] [<c11db934>] (_raw_spin_lock) from [<c1164370>] (sja1105_rcv+0x1f8/0x4e8)
      [  318.620561] [<c1164370>] (sja1105_rcv) from [<c115d7cc>] (dsa_switch_rcv+0x80/0x204)
      [  318.628283] [<c115d7cc>] (dsa_switch_rcv) from [<c0f58c80>] (__netif_receive_skb_one_core+0x50/0x6c)
      [  318.637386] [<c0f58c80>] (__netif_receive_skb_one_core) from [<c0f58f04>] (netif_receive_skb_internal+0xac/0x264)
      [  318.647611] [<c0f58f04>] (netif_receive_skb_internal) from [<c0f59e98>] (napi_gro_receive+0x1d8/0x338)
      [  318.656887] [<c0f59e98>] (napi_gro_receive) from [<c0c298a4>] (gfar_clean_rx_ring+0x328/0x724)
      [  318.665472] [<c0c298a4>] (gfar_clean_rx_ring) from [<c0c29e60>] (gfar_poll_rx_sq+0x34/0x94)
      [  318.673795] [<c0c29e60>] (gfar_poll_rx_sq) from [<c0f5b40c>] (net_rx_action+0x128/0x4f8)
      [  318.681860] [<c0f5b40c>] (net_rx_action) from [<c03022f0>] (__do_softirq+0x148/0x5ac)
      [  318.689666] [<c03022f0>] (__do_softirq) from [<c0355af4>] (irq_exit+0x160/0x170)
      [  318.697040] [<c0355af4>] (irq_exit) from [<c03c6818>] (__handle_domain_irq+0x60/0xb4)
      [  318.704847] [<c03c6818>] (__handle_domain_irq) from [<c07e9440>] (gic_handle_irq+0x58/0x9c)
      [  318.713172] [<c07e9440>] (gic_handle_irq) from [<c0301a70>] (__irq_svc+0x70/0x98)
      [  318.720622] Exception stack(0xc2001f18 to 0xc2001f60)
      [  318.725656] 1f00:                                                       00000001 00000006
      [  318.733805] 1f20: 00000000 c20165c0 ffffe000 c2010cac c2010cf4 00000001 00000000 c2010c88
      [  318.741955] 1f40: c1f7a5a8 00000000 00000000 c2001f68 c03ba140 c030a288 200e0013 ffffffff
      [  318.750110] [<c0301a70>] (__irq_svc) from [<c030a288>] (arch_cpu_idle+0x24/0x3c)
      [  318.757486] [<c030a288>] (arch_cpu_idle) from [<c038a480>] (do_idle+0x1b8/0x2a4)
      [  318.764859] [<c038a480>] (do_idle) from [<c038a94c>] (cpu_startup_entry+0x18/0x1c)
      [  318.772407] [<c038a94c>] (cpu_startup_entry) from [<c1e00f10>] (start_kernel+0x4cc/0x4fc)
      
      Fixes: 844d7edc
      
       ("net: dsa: sja1105: Add a global sja1105_tagger_data structure")
      Signed-off-by: default avatarVladimir Oltean <olteanv@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d6530e5a
    • Dotan Barak's avatar
      net/rds: Fix error handling in rds_ib_add_one() · d64bf89a
      Dotan Barak authored
      
      
      rds_ibdev:ipaddr_list and rds_ibdev:conn_list are initialized
      after allocation some resources such as protection domain.
      If allocation of such resources fail, then these uninitialized
      variables are accessed in rds_ib_dev_free() in failure path. This
      can potentially crash the system. The code has been updated to
      initialize these variables very early in the function.
      Signed-off-by: default avatarDotan Barak <dotanb@dev.mellanox.co.il>
      Signed-off-by: default avatarSudhakar Dindukurti <sudhakar.dindukurti@oracle.com>
      Acked-by: default avatarSantosh Shilimkar <santosh.shilimkar@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d64bf89a
    • Linus Walleij's avatar
      net: dsa: rtl8366: Check VLAN ID and not ports · e8521e53
      Linus Walleij authored
      There has been some confusion between the port number and
      the VLAN ID in this driver. What we need to check for
      validity is the VLAN ID, nothing else.
      
      The current confusion came from assigning a few default
      VLANs for default routing and we need to rewrite that
      properly.
      
      Instead of checking if the port number is a valid VLAN
      ID, check the actual VLAN IDs passed in to the callback
      one by one as expected.
      
      Fixes: d8652956
      
       ("net: dsa: realtek-smi: Add Realtek SMI driver")
      Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      e8521e53
    • Michal Kubecek's avatar
      mlx5: avoid 64-bit division in dr_icm_pool_mr_create() · 8b6b82ad
      Michal Kubecek authored
      Recently added code introduces 64-bit division in dr_icm_pool_mr_create()
      so that build on 32-bit architectures fails with
      
        ERROR: "__umoddi3" [drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.ko] undefined!
      
      As the divisor is always a power of 2, we can use bitwise operation
      instead.
      
      Fixes: 29cf8feb
      
       ("net/mlx5: DR, ICM pool memory allocator")
      Reported-by: default avatarBorislav Petkov <bp@alien8.de>
      Signed-off-by: default avatarMichal Kubecek <mkubecek@suse.cz>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      8b6b82ad
    • Tuong Lien's avatar
      tipc: fix unlimited bundling of small messages · e95584a8
      Tuong Lien authored
      We have identified a problem with the "oversubscription" policy in the
      link transmission code.
      
      When small messages are transmitted, and the sending link has reached
      the transmit window limit, those messages will be bundled and put into
      the link backlog queue. However, bundles of data messages are counted
      at the 'CRITICAL' level, so that the counter for that level, instead of
      the counter for the real, bundled message's level is the one being
      increased.
      Subsequent, to-be-bundled data messages at non-CRITICAL levels continue
      to be tested against the unchanged counter for their own level, while
      contributing to an unrestrained increase at the CRITICAL backlog level.
      
      This leaves a gap in congestion control algorithm for small messages
      that can result in starvation for other users or a "real" CRITICAL
      user. Even that eventually can lead to buffer exhaustion & link reset.
      
      We fix this by keeping a 'target_bskb' buffer pointer at each levels,
      then when bundling, we only bundle messages at the same importance
      level only. This way, we know exactly how many slots a certain level
      have occupied in the queue, so can manage level congestion accurately.
      
      By bundling messages at the same level, we even have more benefits. Let
      consider this:
      - One socket sends 64-byte messages at the 'CRITICAL' level;
      - Another sends 4096-byte messages at the 'LOW' level;
      
      When a 64-byte message comes and is bundled the first time, we put the
      overhead of message bundle to it (+ 40-byte header, data copy, etc.)
      for later use, but the next message can be a 4096-byte one that cannot
      be bundled to the previous one. This means the last bundle carries only
      one payload message which is totally inefficient, as for the receiver
      also! Later on, another 64-byte message comes, now we make a new bundle
      and the same story repeats...
      
      With the new bundling algorithm, this will not happen, the 64-byte
      messages will be bundled together even when the 4096-byte message(s)
      comes in between. However, if the 4096-byte messages are sent at the
      same level i.e. 'CRITICAL', the bundling algorithm will again cause the
      same overhead.
      
      Also, the same will happen even with only one socket sending small
      messages at a rate close to the link transmit's one, so that, when one
      message is bundled, it's transmitted shortly. Then, another message
      comes, a new bundle is created and so on...
      
      We will solve this issue radically by another patch.
      
      Fixes: 365ad353
      
       ("tipc: reduce risk of user starvation during link congestion")
      Reported-by: default avatarHoang Le <hoang.h.le@dektech.com.au>
      Acked-by: default avatarJon Maloy <jon.maloy@ericsson.com>
      Signed-off-by: default avatarTuong Lien <tuong.t.lien@dektech.com.au>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      e95584a8
    • Dongli Zhang's avatar
      xen-netfront: do not use ~0U as error return value for xennet_fill_frags() · a761129e
      Dongli Zhang authored
      xennet_fill_frags() uses ~0U as return value when the sk_buff is not able
      to cache extra fragments. This is incorrect because the return type of
      xennet_fill_frags() is RING_IDX and 0xffffffff is an expected value for
      ring buffer index.
      
      In the situation when the rsp_cons is approaching 0xffffffff, the return
      value of xennet_fill_frags() may become 0xffffffff which xennet_poll() (the
      caller) would regard as error. As a result, queue->rx.rsp_cons is set
      incorrectly because it is updated only when there is error. If there is no
      error, xennet_poll() would be responsible to update queue->rx.rsp_cons.
      Finally, queue->rx.rsp_cons would point to the rx ring buffer entries whose
      queue->rx_skbs[i] and queue->grant_rx_ref[i] are already cleared to NULL.
      This leads to NULL pointer access in the next iteration to process rx ring
      buffer entries.
      
      The symptom is similar to the one fixed in
      commit 00b36850 ("xen-netfront: do not assume sk_buff_head list is
      empty in error handling").
      
      This patch changes the return type of xennet_fill_frags() to indicate
      whether it is successful or failed. The queue->rx.rsp_cons will be
      always updated inside this function.
      
      Fixes: ad4f15dc
      
       ("xen/netfront: don't bug in case of too many frags")
      Signed-off-by: default avatarDongli Zhang <dongli.zhang@oracle.com>
      Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a761129e
    • David Ahern's avatar
      ipv6: Handle race in addrconf_dad_work · a3ce2a21
      David Ahern authored
      Rajendra reported a kernel panic when a link was taken down:
      
      [ 6870.263084] BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8
      [ 6870.271856] IP: [<ffffffff8efc5764>] __ipv6_ifa_notify+0x154/0x290
      
      <snip>
      
      [ 6870.570501] Call Trace:
      [ 6870.573238] [<ffffffff8efc58c6>] ? ipv6_ifa_notify+0x26/0x40
      [ 6870.579665] [<ffffffff8efc98ec>] ? addrconf_dad_completed+0x4c/0x2c0
      [ 6870.586869] [<ffffffff8efe70c6>] ? ipv6_dev_mc_inc+0x196/0x260
      [ 6870.593491] [<ffffffff8efc9c6a>] ? addrconf_dad_work+0x10a/0x430
      [ 6870.600305] [<ffffffff8f01ade4>] ? __switch_to_asm+0x34/0x70
      [ 6870.606732] [<ffffffff8ea93a7a>] ? process_one_work+0x18a/0x430
      [ 6870.613449] [<ffffffff8ea93d6d>] ? worker_thread+0x4d/0x490
      [ 6870.619778] [<ffffffff8ea93d20>] ? process_one_work+0x430/0x430
      [ 6870.626495] [<ffffffff8ea99dd9>] ? kthread+0xd9/0xf0
      [ 6870.632145] [<ffffffff8f01ade4>] ? __switch_to_asm+0x34/0x70
      [ 6870.638573] [<ffffffff8ea99d00>] ? kthread_park+0x60/0x60
      [ 6870.644707] [<ffffffff8f01ae77>] ? ret_from_fork+0x57/0x70
      [ 6870.650936] Code: 31 c0 31 d2 41 b9 20 00 08 02 b9 09 00 00 0
      
      addrconf_dad_work is kicked to be scheduled when a device is brought
      up. There is a race between addrcond_dad_work getting scheduled and
      taking the rtnl lock and a process taking the link down (under rtnl).
      The latter removes the host route from the inet6_addr as part of
      addrconf_ifdown which is run for NETDEV_DOWN. The former attempts
      to use the host route in ipv6_ifa_notify. If the down event removes
      the host route due to the race to the rtnl, then the BUG listed above
      occurs.
      
      This scenario does not occur when the ipv6 address is not kept
      (net.ipv6.conf.all.keep_addr_on_down = 0) as addrconf_ifdown sets the
      state of the ifp to DEAD. Handle when the addresses are kept by checking
      IF_READY which is reset by addrconf_ifdown.
      
      The 'dead' flag for an inet6_addr is set only under rtnl, in
      addrconf_ifdown and it means the device is getting removed (or IPv6 is
      disabled). The interesting cases for changing the idev flag are
      addrconf_notify (NETDEV_UP and NETDEV_CHANGE) and addrconf_ifdown
      (reset the flag). The former does not have the idev lock - only rtnl;
      the latter has both. Based on that the existing dead + IF_READY check
      can be moved to right after the rtnl_lock in addrconf_dad_work.
      
      Fixes: f1705ec1
      
       ("net: ipv6: Make address flushing on ifdown optional")
      Reported-by: default avatarRajendra Dendukuri <rajendra.dendukuri@broadcom.com>
      Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
      Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a3ce2a21
    • Eric Dumazet's avatar
      tcp: adjust rto_base in retransmits_timed_out() · 3256a2d6
      Eric Dumazet authored
      The cited commit exposed an old retransmits_timed_out() bug
      which assumed it could call tcp_model_timeout() with
      TCP_RTO_MIN as rto_base for all states.
      
      But flows in SYN_SENT or SYN_RECV state uses a different
      RTO base (1 sec instead of 200 ms, unless BPF choses
      another value)
      
      This caused a reduction of SYN retransmits from 6 to 4 with
      the default /proc/sys/net/ipv4/tcp_syn_retries value.
      
      Fixes: a41e8a88
      
       ("tcp: better handle TCP_USER_TIMEOUT in SYN_SENT state")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Cc: Yuchung Cheng <ycheng@google.com>
      Cc: Marek Majkowski <marek@cloudflare.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      3256a2d6
    • Dexuan Cui's avatar
      vsock: Fix a lockdep warning in __vsock_release() · 0d9138ff
      Dexuan Cui authored
      
      
      Lockdep is unhappy if two locks from the same class are held.
      
      Fix the below warning for hyperv and virtio sockets (vmci socket code
      doesn't have the issue) by using lock_sock_nested() when __vsock_release()
      is called recursively:
      
      ============================================
      WARNING: possible recursive locking detected
      5.3.0+ #1 Not tainted
      --------------------------------------------
      server/1795 is trying to acquire lock:
      ffff8880c5158990 (sk_lock-AF_VSOCK){+.+.}, at: hvs_release+0x10/0x120 [hv_sock]
      
      but task is already holding lock:
      ffff8880c5158150 (sk_lock-AF_VSOCK){+.+.}, at: __vsock_release+0x2e/0xf0 [vsock]
      
      other info that might help us debug this:
       Possible unsafe locking scenario:
      
             CPU0
             ----
        lock(sk_lock-AF_VSOCK);
        lock(sk_lock-AF_VSOCK);
      
       *** DEADLOCK ***
      
       May be due to missing lock nesting notation
      
      2 locks held by server/1795:
       #0: ffff8880c5d05ff8 (&sb->s_type->i_mutex_key#10){+.+.}, at: __sock_release+0x2d/0xa0
       #1: ffff8880c5158150 (sk_lock-AF_VSOCK){+.+.}, at: __vsock_release+0x2e/0xf0 [vsock]
      
      stack backtrace:
      CPU: 5 PID: 1795 Comm: server Not tainted 5.3.0+ #1
      Call Trace:
       dump_stack+0x67/0x90
       __lock_acquire.cold.67+0xd2/0x20b
       lock_acquire+0xb5/0x1c0
       lock_sock_nested+0x6d/0x90
       hvs_release+0x10/0x120 [hv_sock]
       __vsock_release+0x24/0xf0 [vsock]
       __vsock_release+0xa0/0xf0 [vsock]
       vsock_release+0x12/0x30 [vsock]
       __sock_release+0x37/0xa0
       sock_close+0x14/0x20
       __fput+0xc1/0x250
       task_work_run+0x98/0xc0
       do_exit+0x344/0xc60
       do_group_exit+0x47/0xb0
       get_signal+0x15c/0xc50
       do_signal+0x30/0x720
       exit_to_usermode_loop+0x50/0xa0
       do_syscall_64+0x24e/0x270
       entry_SYSCALL_64_after_hwframe+0x49/0xbe
      RIP: 0033:0x7f4184e85f31
      Tested-by: default avatarStefano Garzarella <sgarzare@redhat.com>
      Signed-off-by: default avatarDexuan Cui <decui@microsoft.com>
      Reviewed-by: default avatarStefano Garzarella <sgarzare@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      0d9138ff
    • Johan Hovold's avatar
      hso: fix NULL-deref on tty open · 8353da9f
      Johan Hovold authored
      Fix NULL-pointer dereference on tty open due to a failure to handle a
      missing interrupt-in endpoint when probing modem ports:
      
      	BUG: kernel NULL pointer dereference, address: 0000000000000006
      	...
      	RIP: 0010:tiocmget_submit_urb+0x1c/0xe0 [hso]
      	...
      	Call Trace:
      	hso_start_serial_device+0xdc/0x140 [hso]
      	hso_serial_open+0x118/0x1b0 [hso]
      	tty_open+0xf1/0x490
      
      Fixes: 542f5482
      
       ("tty: Modem functions for the HSO driver")
      Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      8353da9f
  2. 01 Oct, 2019 27 commits