Re: KASAN: use-after-free Read in hfa384x_usbin_callback

[Andrey Konovalov]

OK, then there's probably no need to test this one, if the other one
was fixed by your patch.

On Thu, Mar 26, 2020 at 12:48 PM Qiujun Huang <anenbupt@xxxxxxxxx> wrote:
>
> Yes, they have the same root cause.
>
> On Thu, Mar 26, 2020 at 6:45 PM Andrey Konovalov <andreyknvl@xxxxxxxxxx> wrote:
> >
> > On Thu, Mar 26, 2020 at 3:52 AM Qiujun Huang <anenbupt@xxxxxxxxx> wrote:
> > >
> > > #syz test: https://github.com/google/kasan.git e17994d1
> >
> > Hi Qiujun,
> >
> > I've already duped this bug to "KASAN: slab-out-of-bounds Read in
> > hfa384x_usbin_callback" since I had assumed they have the same root
> > cause. Are those bugs different? We can undup if needed.
> >
> > Thanks!
> >
> > >
> > > On Mon, Mar 23, 2020 at 8:39 PM syzbot
> > > <syzbot+a57b24d359dc5577634a@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> > > >
> > > > Hello,
> > > >
> > > > syzbot found the following crash on:
> > > >
> > > > HEAD commit:    e17994d1 usb: core: kcov: collect coverage from usb comple..
> > > > git tree:       https://github.com/google/kasan.git usb-fuzzer
> > > > console output: https://syzkaller.appspot.com/x/log.txt?x=15217373e00000
> > > > kernel config:  https://syzkaller.appspot.com/x/.config?x=5d64370c438bc60
> > > > dashboard link: https://syzkaller.appspot.com/bug?extid=a57b24d359dc5577634a
> > > > compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> > > > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14a720ade00000
> > > > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1467b755e00000
> > > >
> > > > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > > > Reported-by: syzbot+a57b24d359dc5577634a@xxxxxxxxxxxxxxxxxxxxxxxxx
> > > >
> > > > ==================================================================
> > > > BUG: KASAN: use-after-free in memcpy include/linux/string.h:381 [inline]
> > > > BUG: KASAN: use-after-free in skb_put_data include/linux/skbuff.h:2284 [inline]
> > > > BUG: KASAN: use-after-free in hfa384x_int_rxmonitor drivers/staging/wlan-ng/hfa384x_usb.c:3412 [inline]
> > > > BUG: KASAN: use-after-free in hfa384x_usbin_rx drivers/staging/wlan-ng/hfa384x_usb.c:3312 [inline]
> > > > BUG: KASAN: use-after-free in hfa384x_usbin_callback+0x1993/0x2360 drivers/staging/wlan-ng/hfa384x_usb.c:3026
> > > > Read of size 34945 at addr ffff8881cda9f33c by task swapper/0/0
> > > >
> > > > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc5-syzkaller #0
> > > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > > > Call Trace:
> > > >  <IRQ>
> > > >  __dump_stack lib/dump_stack.c:77 [inline]
> > > >  dump_stack+0xef/0x16e lib/dump_stack.c:118
> > > >  print_address_description.constprop.0.cold+0xd3/0x314 mm/kasan/report.c:374
> > > >  __kasan_report.cold+0x37/0x77 mm/kasan/report.c:506
> > > >  kasan_report+0xe/0x20 mm/kasan/common.c:641
> > > >  check_memory_region_inline mm/kasan/generic.c:185 [inline]
> > > >  check_memory_region+0x152/0x1c0 mm/kasan/generic.c:192
> > > >  memcpy+0x20/0x50 mm/kasan/common.c:127
> > > >  memcpy include/linux/string.h:381 [inline]
> > > >  skb_put_data include/linux/skbuff.h:2284 [inline]
> > > >  hfa384x_int_rxmonitor drivers/staging/wlan-ng/hfa384x_usb.c:3412 [inline]
> > > >  hfa384x_usbin_rx drivers/staging/wlan-ng/hfa384x_usb.c:3312 [inline]
> > > >  hfa384x_usbin_callback+0x1993/0x2360 drivers/staging/wlan-ng/hfa384x_usb.c:3026
> > > >  __usb_hcd_giveback_urb+0x29a/0x550 drivers/usb/core/hcd.c:1650
> > > >  usb_hcd_giveback_urb+0x368/0x420 drivers/usb/core/hcd.c:1716
> > > >  dummy_timer+0x1258/0x32ae drivers/usb/gadget/udc/dummy_hcd.c:1966
> > > >  call_timer_fn+0x195/0x6f0 kernel/time/timer.c:1404
> > > >  expire_timers kernel/time/timer.c:1449 [inline]
> > > >  __run_timers kernel/time/timer.c:1773 [inline]
> > > >  __run_timers kernel/time/timer.c:1740 [inline]
> > > >  run_timer_softirq+0x5f9/0x1500 kernel/time/timer.c:1786
> > > >  __do_softirq+0x21e/0x950 kernel/softirq.c:292
> > > >  invoke_softirq kernel/softirq.c:373 [inline]
> > > >  irq_exit+0x178/0x1a0 kernel/softirq.c:413
> > > >  exiting_irq arch/x86/include/asm/apic.h:546 [inline]
> > > >  smp_apic_timer_interrupt+0x141/0x540 arch/x86/kernel/apic/apic.c:1146
> > > >  apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
> > > >  </IRQ>
> > > > RIP: 0010:default_idle+0x28/0x300 arch/x86/kernel/process.c:696
> > > > Code: cc cc 41 56 41 55 65 44 8b 2d 44 77 72 7a 41 54 55 53 0f 1f 44 00 00 e8 b6 62 b5 fb e9 07 00 00 00 0f 00 2d ea 0c 53 00 fb f4 <65> 44 8b 2d 20 77 72 7a 0f 1f 44 00 00 5b 5d 41 5c 41 5d 41 5e c3
> > > > RSP: 0018:ffffffff87007d80 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
> > > > RAX: 0000000000000007 RBX: ffffffff8702cc40 RCX: 0000000000000000
> > > > RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffffffff8702d48c
> > > > RBP: fffffbfff0e05988 R08: ffffffff8702cc40 R09: 0000000000000000
> > > > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> > > > R13: 0000000000000000 R14: ffffffff87e607c0 R15: 0000000000000000
> > > >  cpuidle_idle_call kernel/sched/idle.c:154 [inline]
> > > >  do_idle+0x3e0/0x500 kernel/sched/idle.c:269
> > > >  cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:361
> > > >  start_kernel+0xe16/0xe5a init/main.c:998
> > > >  secondary_startup_64+0xb6/0xc0 arch/x86/kernel/head_64.S:242
> > > >
> > > > The buggy address belongs to the page:
> > > > page:ffffea000736a600 refcount:32769 mapcount:0 mapping:0000000000000000 index:0x0 compound_mapcount: 0
> > > > flags: 0x200000000010000(head)
> > > > raw: 0200000000010000 dead000000000100 dead000000000122 0000000000000000
> > > > raw: 0000000000000000 0000000000000000 00008001ffffffff 0000000000000000
> > > > page dumped because: kasan: bad access detected
> > > >
> > > > Memory state around the buggy address:
> > > >  ffff8881cda9ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > > >  ffff8881cda9ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > > > >ffff8881cdaa0000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > > >                    ^
> > > >  ffff8881cdaa0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > > >  ffff8881cdaa0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > > > ==================================================================
> > > >
> > > >
> > > > ---
> > > > This bug is generated by a bot. It may contain errors.
> > > > See https://goo.gl/tpsmEJ for more information about syzbot.
> > > > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxxx
> > > >
> > > > syzbot will keep track of this bug report. See:
> > > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> > > > syzbot can test patches for this bug, for details see:
> > > > https://goo.gl/tpsmEJ#testing-patches