1. 19 6月, 2017 7 次提交
  2. 16 6月, 2017 1 次提交
    • A
      USB: gadgetfs, dummy-hcd, net2280: fix locking for callbacks · f16443a0
      Alan Stern 提交于
      Using the syzkaller kernel fuzzer, Andrey Konovalov generated the
      following error in gadgetfs:
      
      > BUG: KASAN: use-after-free in __lock_acquire+0x3069/0x3690
      > kernel/locking/lockdep.c:3246
      > Read of size 8 at addr ffff88003a2bdaf8 by task kworker/3:1/903
      >
      > CPU: 3 PID: 903 Comm: kworker/3:1 Not tainted 4.12.0-rc4+ #35
      > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
      > Workqueue: usb_hub_wq hub_event
      > Call Trace:
      >  __dump_stack lib/dump_stack.c:16 [inline]
      >  dump_stack+0x292/0x395 lib/dump_stack.c:52
      >  print_address_description+0x78/0x280 mm/kasan/report.c:252
      >  kasan_report_error mm/kasan/report.c:351 [inline]
      >  kasan_report+0x230/0x340 mm/kasan/report.c:408
      >  __asan_report_load8_noabort+0x19/0x20 mm/kasan/report.c:429
      >  __lock_acquire+0x3069/0x3690 kernel/locking/lockdep.c:3246
      >  lock_acquire+0x22d/0x560 kernel/locking/lockdep.c:3855
      >  __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
      >  _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151
      >  spin_lock include/linux/spinlock.h:299 [inline]
      >  gadgetfs_suspend+0x89/0x130 drivers/usb/gadget/legacy/inode.c:1682
      >  set_link_state+0x88e/0xae0 drivers/usb/gadget/udc/dummy_hcd.c:455
      >  dummy_hub_control+0xd7e/0x1fb0 drivers/usb/gadget/udc/dummy_hcd.c:2074
      >  rh_call_control drivers/usb/core/hcd.c:689 [inline]
      >  rh_urb_enqueue drivers/usb/core/hcd.c:846 [inline]
      >  usb_hcd_submit_urb+0x92f/0x20b0 drivers/usb/core/hcd.c:1650
      >  usb_submit_urb+0x8b2/0x12c0 drivers/usb/core/urb.c:542
      >  usb_start_wait_urb+0x148/0x5b0 drivers/usb/core/message.c:56
      >  usb_internal_control_msg drivers/usb/core/message.c:100 [inline]
      >  usb_control_msg+0x341/0x4d0 drivers/usb/core/message.c:151
      >  usb_clear_port_feature+0x74/0xa0 drivers/usb/core/hub.c:412
      >  hub_port_disable+0x123/0x510 drivers/usb/core/hub.c:4177
      >  hub_port_init+0x1ed/0x2940 drivers/usb/core/hub.c:4648
      >  hub_port_connect drivers/usb/core/hub.c:4826 [inline]
      >  hub_port_connect_change drivers/usb/core/hub.c:4999 [inline]
      >  port_event drivers/usb/core/hub.c:5105 [inline]
      >  hub_event+0x1ae1/0x3d40 drivers/usb/core/hub.c:5185
      >  process_one_work+0xc08/0x1bd0 kernel/workqueue.c:2097
      >  process_scheduled_works kernel/workqueue.c:2157 [inline]
      >  worker_thread+0xb2b/0x1860 kernel/workqueue.c:2233
      >  kthread+0x363/0x440 kernel/kthread.c:231
      >  ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:424
      >
      > Allocated by task 9958:
      >  save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59
      >  save_stack+0x43/0xd0 mm/kasan/kasan.c:513
      >  set_track mm/kasan/kasan.c:525 [inline]
      >  kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:617
      >  kmem_cache_alloc_trace+0x87/0x280 mm/slub.c:2745
      >  kmalloc include/linux/slab.h:492 [inline]
      >  kzalloc include/linux/slab.h:665 [inline]
      >  dev_new drivers/usb/gadget/legacy/inode.c:170 [inline]
      >  gadgetfs_fill_super+0x24f/0x540 drivers/usb/gadget/legacy/inode.c:1993
      >  mount_single+0xf6/0x160 fs/super.c:1192
      >  gadgetfs_mount+0x31/0x40 drivers/usb/gadget/legacy/inode.c:2019
      >  mount_fs+0x9c/0x2d0 fs/super.c:1223
      >  vfs_kern_mount.part.25+0xcb/0x490 fs/namespace.c:976
      >  vfs_kern_mount fs/namespace.c:2509 [inline]
      >  do_new_mount fs/namespace.c:2512 [inline]
      >  do_mount+0x41b/0x2d90 fs/namespace.c:2834
      >  SYSC_mount fs/namespace.c:3050 [inline]
      >  SyS_mount+0xb0/0x120 fs/namespace.c:3027
      >  entry_SYSCALL_64_fastpath+0x1f/0xbe
      >
      > Freed by task 9960:
      >  save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59
      >  save_stack+0x43/0xd0 mm/kasan/kasan.c:513
      >  set_track mm/kasan/kasan.c:525 [inline]
      >  kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:590
      >  slab_free_hook mm/slub.c:1357 [inline]
      >  slab_free_freelist_hook mm/slub.c:1379 [inline]
      >  slab_free mm/slub.c:2961 [inline]
      >  kfree+0xed/0x2b0 mm/slub.c:3882
      >  put_dev+0x124/0x160 drivers/usb/gadget/legacy/inode.c:163
      >  gadgetfs_kill_sb+0x33/0x60 drivers/usb/gadget/legacy/inode.c:2027
      >  deactivate_locked_super+0x8d/0xd0 fs/super.c:309
      >  deactivate_super+0x21e/0x310 fs/super.c:340
      >  cleanup_mnt+0xb7/0x150 fs/namespace.c:1112
      >  __cleanup_mnt+0x1b/0x20 fs/namespace.c:1119
      >  task_work_run+0x1a0/0x280 kernel/task_work.c:116
      >  exit_task_work include/linux/task_work.h:21 [inline]
      >  do_exit+0x18a8/0x2820 kernel/exit.c:878
      >  do_group_exit+0x14e/0x420 kernel/exit.c:982
      >  get_signal+0x784/0x1780 kernel/signal.c:2318
      >  do_signal+0xd7/0x2130 arch/x86/kernel/signal.c:808
      >  exit_to_usermode_loop+0x1ac/0x240 arch/x86/entry/common.c:157
      >  prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
      >  syscall_return_slowpath+0x3ba/0x410 arch/x86/entry/common.c:263
      >  entry_SYSCALL_64_fastpath+0xbc/0xbe
      >
      > The buggy address belongs to the object at ffff88003a2bdae0
      >  which belongs to the cache kmalloc-1024 of size 1024
      > The buggy address is located 24 bytes inside of
      >  1024-byte region [ffff88003a2bdae0, ffff88003a2bdee0)
      > The buggy address belongs to the page:
      > page:ffffea0000e8ae00 count:1 mapcount:0 mapping:          (null)
      > index:0x0 compound_mapcount: 0
      > flags: 0x100000000008100(slab|head)
      > raw: 0100000000008100 0000000000000000 0000000000000000 0000000100170017
      > raw: ffffea0000ed3020 ffffea0000f5f820 ffff88003e80efc0 0000000000000000
      > page dumped because: kasan: bad access detected
      >
      > Memory state around the buggy address:
      >  ffff88003a2bd980: fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
      >  ffff88003a2bda00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
      > >ffff88003a2bda80: fc fc fc fc fc fc fc fc fc fc fc fc fb fb fb fb
      >                                                                 ^
      >  ffff88003a2bdb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
      >  ffff88003a2bdb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
      > ==================================================================
      
      What this means is that the gadgetfs_suspend() routine was trying to
      access dev->lock after it had been deallocated.  The root cause is a
      race in the dummy_hcd driver; the dummy_udc_stop() routine can race
      with the rest of the driver because it contains no locking.  And even
      when proper locking is added, it can still race with the
      set_link_state() function because that function incorrectly drops the
      private spinlock before invoking any gadget driver callbacks.
      
      The result of this race, as seen above, is that set_link_state() can
      invoke a callback in gadgetfs even after gadgetfs has been unbound
      from dummy_hcd's UDC and its private data structures have been
      deallocated.
      
      include/linux/usb/gadget.h documents that the ->reset, ->disconnect,
      ->suspend, and ->resume callbacks may be invoked in interrupt context.
      In general this is necessary, to prevent races with gadget driver
      removal.  This patch fixes dummy_hcd to retain the spinlock across
      these calls, and it adds a spinlock acquisition to dummy_udc_stop() to
      prevent the race.
      
      The net2280 driver makes the same mistake of dropping the private
      spinlock for its ->disconnect and ->reset callback invocations.  The
      patch fixes it too.
      
      Lastly, since gadgetfs_suspend() may be invoked in interrupt context,
      it cannot assume that interrupts are enabled when it runs.  It must
      use spin_lock_irqsave() instead of spin_lock_irq().  The patch fixes
      that bug as well.
      Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
      Reported-and-tested-by: NAndrey Konovalov <andreyknvl@google.com>
      CC: <stable@vger.kernel.org>
      Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f16443a0
  3. 15 6月, 2017 1 次提交
  4. 13 6月, 2017 12 次提交
  5. 09 6月, 2017 1 次提交
    • A
      USB: gadget: fix GPF in gadgetfs · f50b878f
      Alan Stern 提交于
      A NULL-pointer dereference bug in gadgetfs was uncovered by syzkaller:
      
      > kasan: GPF could be caused by NULL-ptr deref or user memory access
      > general protection fault: 0000 [#1] SMP KASAN
      > Dumping ftrace buffer:
      >    (ftrace buffer empty)
      > Modules linked in:
      > CPU: 2 PID: 4820 Comm: syz-executor0 Not tainted 4.12.0-rc4+ #5
      > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
      > task: ffff880039542dc0 task.stack: ffff88003bdd0000
      > RIP: 0010:__list_del_entry_valid+0x7e/0x170 lib/list_debug.c:51
      > RSP: 0018:ffff88003bdd6e50 EFLAGS: 00010246
      > RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000010000
      > RDX: 0000000000000000 RSI: ffffffff86504948 RDI: ffffffff86504950
      > RBP: ffff88003bdd6e68 R08: ffff880039542dc0 R09: ffffffff8778ce00
      > R10: ffff88003bdd6e68 R11: dffffc0000000000 R12: 0000000000000000
      > R13: dffffc0000000000 R14: 1ffff100077badd2 R15: ffffffff864d2e40
      > FS:  0000000000000000(0000) GS:ffff88006dc00000(0000) knlGS:0000000000000000
      > CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      > CR2: 000000002014aff9 CR3: 0000000006022000 CR4: 00000000000006e0
      > Call Trace:
      >  __list_del_entry include/linux/list.h:116 [inline]
      >  list_del include/linux/list.h:124 [inline]
      >  usb_gadget_unregister_driver+0x166/0x4c0 drivers/usb/gadget/udc/core.c:1387
      >  dev_release+0x80/0x160 drivers/usb/gadget/legacy/inode.c:1187
      >  __fput+0x332/0x7f0 fs/file_table.c:209
      >  ____fput+0x15/0x20 fs/file_table.c:245
      >  task_work_run+0x19b/0x270 kernel/task_work.c:116
      >  exit_task_work include/linux/task_work.h:21 [inline]
      >  do_exit+0x18a3/0x2820 kernel/exit.c:878
      >  do_group_exit+0x149/0x420 kernel/exit.c:982
      >  get_signal+0x77f/0x1780 kernel/signal.c:2318
      >  do_signal+0xd2/0x2130 arch/x86/kernel/signal.c:808
      >  exit_to_usermode_loop+0x1a7/0x240 arch/x86/entry/common.c:157
      >  prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
      >  syscall_return_slowpath+0x3ba/0x410 arch/x86/entry/common.c:263
      >  entry_SYSCALL_64_fastpath+0xbc/0xbe
      > RIP: 0033:0x4461f9
      > RSP: 002b:00007fdac2b1ecf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
      > RAX: fffffffffffffe00 RBX: 00000000007080c8 RCX: 00000000004461f9
      > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000007080c8
      > RBP: 00000000007080a8 R08: 0000000000000000 R09: 0000000000000000
      > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
      > R13: 0000000000000000 R14: 00007fdac2b1f9c0 R15: 00007fdac2b1f700
      > Code: 00 00 00 00 ad de 49 39 c4 74 6a 48 b8 00 02 00 00 00 00 ad de
      > 48 89 da 48 39 c3 74 74 48 c1 ea 03 48 b8 00 00 00 00 00 fc ff df <80>
      > 3c 02 00 0f 85 92 00 00 00 48 8b 13 48 39 f2 75 66 49 8d 7c
      > RIP: __list_del_entry_valid+0x7e/0x170 lib/list_debug.c:51 RSP: ffff88003bdd6e50
      > ---[ end trace 30e94b1eec4831c8 ]---
      > Kernel panic - not syncing: Fatal exception
      
      The bug was caused by dev_release() failing to turn off its
      gadget_registered flag after unregistering the gadget driver.  As a
      result, when a later user closed the device file before writing a
      valid set of descriptors, dev_release() thought the gadget had been
      registered and tried to unregister it, even though it had not been.
      This led to the NULL pointer dereference.
      
      The fix is simple: turn off the flag when the gadget is unregistered.
      Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
      Reported-and-tested-by: NAndrey Konovalov <andreyknvl@google.com>
      CC: <stable@vger.kernel.org>
      Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
      f50b878f
  6. 08 6月, 2017 1 次提交
    • D
      net: Fix inconsistent teardown and release of private netdev state. · cf124db5
      David S. Miller 提交于
      Network devices can allocate reasources and private memory using
      netdev_ops->ndo_init().  However, the release of these resources
      can occur in one of two different places.
      
      Either netdev_ops->ndo_uninit() or netdev->destructor().
      
      The decision of which operation frees the resources depends upon
      whether it is necessary for all netdev refs to be released before it
      is safe to perform the freeing.
      
      netdev_ops->ndo_uninit() presumably can occur right after the
      NETDEV_UNREGISTER notifier completes and the unicast and multicast
      address lists are flushed.
      
      netdev->destructor(), on the other hand, does not run until the
      netdev references all go away.
      
      Further complicating the situation is that netdev->destructor()
      almost universally does also a free_netdev().
      
      This creates a problem for the logic in register_netdevice().
      Because all callers of register_netdevice() manage the freeing
      of the netdev, and invoke free_netdev(dev) if register_netdevice()
      fails.
      
      If netdev_ops->ndo_init() succeeds, but something else fails inside
      of register_netdevice(), it does call ndo_ops->ndo_uninit().  But
      it is not able to invoke netdev->destructor().
      
      This is because netdev->destructor() will do a free_netdev() and
      then the caller of register_netdevice() will do the same.
      
      However, this means that the resources that would normally be released
      by netdev->destructor() will not be.
      
      Over the years drivers have added local hacks to deal with this, by
      invoking their destructor parts by hand when register_netdevice()
      fails.
      
      Many drivers do not try to deal with this, and instead we have leaks.
      
      Let's close this hole by formalizing the distinction between what
      private things need to be freed up by netdev->destructor() and whether
      the driver needs unregister_netdevice() to perform the free_netdev().
      
      netdev->priv_destructor() performs all actions to free up the private
      resources that used to be freed by netdev->destructor(), except for
      free_netdev().
      
      netdev->needs_free_netdev is a boolean that indicates whether
      free_netdev() should be done at the end of unregister_netdevice().
      
      Now, register_netdevice() can sanely release all resources after
      ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit()
      and netdev->priv_destructor().
      
      And at the end of unregister_netdevice(), we invoke
      netdev->priv_destructor() and optionally call free_netdev().
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      cf124db5
  7. 06 6月, 2017 1 次提交
  8. 02 6月, 2017 10 次提交
  9. 17 5月, 2017 6 次提交