queue-4.9/mdio_bus-fix-use-after-free-on-device_register-fails.patch

   1 From foo@baz Fri Mar 15 21:00:09 PDT 2019
   2 From: YueHaibing <yuehaibing@huawei.com>
   3 Date: Thu, 21 Feb 2019 22:42:01 +0800
   4 Subject: mdio_bus: Fix use-after-free on device_register fails
   5
   6 From: YueHaibing <yuehaibing@huawei.com>
   7
   8 [ Upstream commit 6ff7b060535e87c2ae14dd8548512abfdda528fb ]
   9
  10 KASAN has found use-after-free in fixed_mdio_bus_init,
  11 commit 0c692d07842a ("drivers/net/phy/mdio_bus.c: call
  12 put_device on device_register() failure") call put_device()
  13 while device_register() fails,give up the last reference
  14 to the device and allow mdiobus_release to be executed
  15 ,kfreeing the bus. However in most drives, mdiobus_free
  16 be called to free the bus while mdiobus_register fails.
  17 use-after-free occurs when access bus again, this patch
  18 revert it to let mdiobus_free free the bus.
  19
  20 KASAN report details as below:
  21
  22 BUG: KASAN: use-after-free in mdiobus_free+0x85/0x90 drivers/net/phy/mdio_bus.c:482
  23 Read of size 4 at addr ffff8881dc824d78 by task syz-executor.0/3524
  24
  25 CPU: 1 PID: 3524 Comm: syz-executor.0 Not tainted 5.0.0-rc7+ #45
  26 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
  27 Call Trace:
  28  __dump_stack lib/dump_stack.c:77 [inline]
  29  dump_stack+0xfa/0x1ce lib/dump_stack.c:113
  30  print_address_description+0x65/0x270 mm/kasan/report.c:187
  31  kasan_report+0x149/0x18d mm/kasan/report.c:317
  32  mdiobus_free+0x85/0x90 drivers/net/phy/mdio_bus.c:482
  33  fixed_mdio_bus_init+0x283/0x1000 [fixed_phy]
  34  ? 0xffffffffc0e40000
  35  ? 0xffffffffc0e40000
  36  ? 0xffffffffc0e40000
  37  do_one_initcall+0xfa/0x5ca init/main.c:887
  38  do_init_module+0x204/0x5f6 kernel/module.c:3460
  39  load_module+0x66b2/0x8570 kernel/module.c:3808
  40  __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902
  41  do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
  42  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  43 RIP: 0033:0x462e99
  44 Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
  45 RSP: 002b:00007f6215c19c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
  46 RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462e99
  47 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003
  48 RBP: 00007f6215c19c70 R08: 0000000000000000 R09: 0000000000000000
  49 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6215c1a6bc
  50 R13: 00000000004bcefb R14: 00000000006f7030 R15: 0000000000000004
  51
  52 Allocated by task 3524:
  53  set_track mm/kasan/common.c:85 [inline]
  54  __kasan_kmalloc.constprop.3+0xa0/0xd0 mm/kasan/common.c:496
  55  kmalloc include/linux/slab.h:545 [inline]
  56  kzalloc include/linux/slab.h:740 [inline]
  57  mdiobus_alloc_size+0x54/0x1b0 drivers/net/phy/mdio_bus.c:143
  58  fixed_mdio_bus_init+0x163/0x1000 [fixed_phy]
  59  do_one_initcall+0xfa/0x5ca init/main.c:887
  60  do_init_module+0x204/0x5f6 kernel/module.c:3460
  61  load_module+0x66b2/0x8570 kernel/module.c:3808
  62  __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902
  63  do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
  64  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  65
  66 Freed by task 3524:
  67  set_track mm/kasan/common.c:85 [inline]
  68  __kasan_slab_free+0x130/0x180 mm/kasan/common.c:458
  69  slab_free_hook mm/slub.c:1409 [inline]
  70  slab_free_freelist_hook mm/slub.c:1436 [inline]
  71  slab_free mm/slub.c:2986 [inline]
  72  kfree+0xe1/0x270 mm/slub.c:3938
  73  device_release+0x78/0x200 drivers/base/core.c:919
  74  kobject_cleanup lib/kobject.c:662 [inline]
  75  kobject_release lib/kobject.c:691 [inline]
  76  kref_put include/linux/kref.h:67 [inline]
  77  kobject_put+0x146/0x240 lib/kobject.c:708
  78  put_device+0x1c/0x30 drivers/base/core.c:2060
  79  __mdiobus_register+0x483/0x560 drivers/net/phy/mdio_bus.c:382
  80  fixed_mdio_bus_init+0x26b/0x1000 [fixed_phy]
  81  do_one_initcall+0xfa/0x5ca init/main.c:887
  82  do_init_module+0x204/0x5f6 kernel/module.c:3460
  83  load_module+0x66b2/0x8570 kernel/module.c:3808
  84  __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902
  85  do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
  86  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  87
  88 The buggy address belongs to the object at ffff8881dc824c80
  89  which belongs to the cache kmalloc-2k of size 2048
  90 The buggy address is located 248 bytes inside of
  91  2048-byte region [ffff8881dc824c80, ffff8881dc825480)
  92 The buggy address belongs to the page:
  93 page:ffffea0007720800 count:1 mapcount:0 mapping:ffff8881f6c02800 index:0x0 compound_mapcount: 0
  94 flags: 0x2fffc0000010200(slab|head)
  95 raw: 02fffc0000010200 0000000000000000 0000000500000001 ffff8881f6c02800
  96 raw: 0000000000000000 00000000800f000f 00000001ffffffff 0000000000000000
  97 page dumped because: kasan: bad access detected
  98
  99 Memory state around the buggy address:
 100  ffff8881dc824c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 101  ffff8881dc824c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 102 >ffff8881dc824d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 103                                                                 ^
 104  ffff8881dc824d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 105  ffff8881dc824e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 106
 107 Fixes: 0c692d07842a ("drivers/net/phy/mdio_bus.c: call put_device on device_register() failure")
 108 Signed-off-by: YueHaibing <yuehaibing@huawei.com>
 109 Reviewed-by: Andrew Lunn <andrew@lunn.ch>
 110 Signed-off-by: David S. Miller <davem@davemloft.net>
 111 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 112 ---
 113  drivers/net/phy/mdio_bus.c |    1 -
 114  1 file changed, 1 deletion(-)
 115
 116 --- a/drivers/net/phy/mdio_bus.c
 117 +++ b/drivers/net/phy/mdio_bus.c
 118 @@ -319,7 +319,6 @@ int __mdiobus_register(struct mii_bus *b
 119         err = device_register(&bus->dev);
 120         if (err) {
 121                 pr_err("mii_bus %s failed to register\n", bus->id);
 122 -               put_device(&bus->dev);
 123                 return -EINVAL;
 124         }
 125