On Sat, Sep 22, 2018 at 08:41:55PM -0400, Waiman Long wrote: > 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. > > Signed-off-by: Waiman Long <longman@xxxxxxxxxx> Patch applied. Thanks. -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
