tree 7a8759d52e00766b1d8154015109836b25a14a4b
parent 685a8f97735cf66f280b2658d27c9d6c85c229d7
author Waiman Long <longman@redhat.com> 1537663315 -0400
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1539154403 +0200

crypto: qat - Fix KASAN stack-out-of-bounds bug in adf_probe()

commit ba439a6cbfa2936a6713f64cb499de7943673fe3 upstream.

The following KASAN warning was printed when booting a 64-bit kernel
on some systems with Intel CPUs:

[   44.512826] ==================================================================
[   44.520165] BUG: KASAN: stack-out-of-bounds in find_first_bit+0xb0/0xc0
[   44.526786] Read of size 8 at addr ffff88041e02fc50 by task kworker/0:2/124

[   44.535253] CPU: 0 PID: 124 Comm: kworker/0:2 Tainted: G               X --------- ---  4.18.0-12.el8.x86_64+debug #1
[   44.545858] Hardware name: Intel Corporation PURLEY/PURLEY, BIOS BKVDTRL1.86B.0005.D08.1712070559 12/07/2017
[   44.555682] Workqueue: events work_for_cpu_fn
[   44.560043] Call Trace:
[   44.562502]  dump_stack+0x9a/0xe9
[   44.565832]  print_address_description+0x65/0x22e
[   44.570683]  ? find_first_bit+0xb0/0xc0
[   44.570689]  kasan_report.cold.6+0x92/0x19f
[   44.578726]  find_first_bit+0xb0/0xc0
[   44.578737]  adf_probe+0x9eb/0x19a0 [qat_c62x]
[   44.578751]  ? adf_remove+0x110/0x110 [qat_c62x]
[   44.591490]  ? mark_held_locks+0xc8/0x140
[   44.591498]  ? _raw_spin_unlock+0x30/0x30
[   44.591505]  ? trace_hardirqs_on_caller+0x381/0x570
[   44.604418]  ? adf_remove+0x110/0x110 [qat_c62x]
[   44.604427]  local_pci_probe+0xd4/0x180
[   44.604432]  ? pci_device_shutdown+0x110/0x110
[   44.617386]  work_for_cpu_fn+0x51/0xa0
[   44.621145]  process_one_work+0x8fe/0x16e0
[   44.625263]  ? pwq_dec_nr_in_flight+0x2d0/0x2d0
[   44.629799]  ? lock_acquire+0x14c/0x400
[   44.633645]  ? move_linked_works+0x12e/0x2a0
[   44.637928]  worker_thread+0x536/0xb50
[   44.641690]  ? __kthread_parkme+0xb6/0x180
[   44.645796]  ? process_one_work+0x16e0/0x16e0
[   44.650160]  kthread+0x30c/0x3d0
[   44.653400]  ? kthread_create_worker_on_cpu+0xc0/0xc0
[   44.658457]  ret_from_fork+0x3a/0x50

[   44.663557] The buggy address belongs to the page:
[   44.668350] page:ffffea0010780bc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[   44.676356] flags: 0x17ffffc0000000()
[   44.680023] raw: 0017ffffc0000000 ffffea0010780bc8 ffffea0010780bc8 0000000000000000
[   44.687769] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
[   44.695510] page dumped because: kasan: bad access detected

[   44.702578] Memory state around the buggy address:
[   44.707372]  ffff88041e02fb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   44.714593]  ffff88041e02fb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   44.721810] >ffff88041e02fc00: 00 00 00 00 00 00 f1 f1 f1 f1 04 f2 f2 f2 f2 f2
[   44.729028]                                                  ^
[   44.734864]  ffff88041e02fc80: f2 f2 00 00 00 00 f3 f3 f3 f3 00 00 00 00 00 00
[   44.742082]  ffff88041e02fd00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[   44.749299] ==================================================================

Looking into the code:

  int ret, bar_mask;
    :
  for_each_set_bit(bar_nr, (const unsigned long *)&bar_mask,

It is casting a 32-bit integer pointer to a 64-bit unsigned long
pointer. There are two problems here. First, the 32-bit pointer address
may not be 64-bit aligned. Secondly, it is accessing an extra 4 bytes.

This is fixed by changing the bar_mask type to unsigned long.

Cc: <stable@vger.kernel.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>