Subject: Re: WARNING: ODEBUG bug in rsi_probe

From: Johan Hovold <[email-masked]>
Date: Thu, 28 Nov 2019 19:17:46 +0100

On Thu, Nov 28, 2019 at 07:12:26PM +0100, Andrey Konovalov wrote:
> On Thu, Nov 28, 2019 at 7:00 PM Johan Hovold <[email-masked]> wrote:
> >
> > On Fri, Apr 19, 2019 at 04:54:06PM -0700, syzbot wrote:
> > > syzbot has found a reproducer for the following crash on:
> > >
> > > HEAD commit:    d34f9519 usb-fuzzer: main usb gadget fuzzer driver
> > > git tree:       https://github.com/google/kasan/tree/usb-fuzzer
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=13431e7b200000
> > > kernel config:  https://syzkaller.appspot.com/x/.config?x=c73d1bb5aeaeae20
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=1d1597a5aa3679c65b9f
> > > compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> > > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12534fdd200000
> > > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=147c9247200000
> > >
> > > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > > Reported-by: [email-masked]
> > >
> > > rsi_91x: rsi_load_firmware: REGOUT read failed
> > > rsi_91x: rsi_hal_device_init: Failed to load TA instructions
> > > rsi_91x: rsi_probe: Failed in device init
> > > ------------[ cut here ]------------
> > > ODEBUG: free active (active state 0) object type: timer_list hint:
> > > bl_cmd_timeout+0x0/0x50 drivers/net/wireless/rsi/rsi_91x_hal.c:577
> > > WARNING: CPU: 0 PID: 563 at lib/debugobjects.c:325
> > > debug_print_object+0x162/0x250 lib/debugobjects.c:325
> > > Kernel panic - not syncing: panic_on_warn set ...
> > > CPU: 0 PID: 563 Comm: kworker/0:2 Not tainted 5.1.0-rc5-319617-gd34f951 #4
> > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> > > Google 01/01/2011
> > > Workqueue: usb_hub_wq hub_event
> > > Call Trace:
> > >   __dump_stack lib/dump_stack.c:77 [inline]
> > >   dump_stack+0xe8/0x16e lib/dump_stack.c:113
> > >   panic+0x29d/0x5f2 kernel/panic.c:214
> > >   __warn.cold+0x20/0x48 kernel/panic.c:571
> > >   report_bug+0x262/0x2a0 lib/bug.c:186
> > >   fixup_bug arch/x86/kernel/traps.c:179 [inline]
> > >   fixup_bug arch/x86/kernel/traps.c:174 [inline]
> > >   do_error_trap+0x130/0x1f0 arch/x86/kernel/traps.c:272
> > >   do_invalid_op+0x37/0x40 arch/x86/kernel/traps.c:291
> > >   invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
> > > RIP: 0010:debug_print_object+0x162/0x250 lib/debugobjects.c:325
> > > Code: dd c0 a8 b3 8e 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 bf 00 00 00 48
> > > 8b 14 dd c0 a8 b3 8e 48 c7 c7 40 9d b3 8e e8 8e c3 d2 fd <0f> 0b 83 05 f9
> > > 0f 5a 10 01 48 83 c4 20 5b 5d 41 5c 41 5d c3 48 89
> > > RSP: 0018:ffff88809e1ef110 EFLAGS: 00010086
> > > RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
> > > RDX: 0000000000000000 RSI: ffffffff815b1d22 RDI: ffffed1013c3de14
> > > RBP: 0000000000000001 R08: ffff88809e1cb100 R09: ffffed1015a03edb
> > > R10: ffffed1015a03eda R11: ffff8880ad01f6d7 R12: ffffffff917e77c0
> > > R13: ffffffff8161e740 R14: ffffffff96d3ea28 R15: ffff8880a5a75f60
> > >   __debug_check_no_obj_freed lib/debugobjects.c:785 [inline]
> > >   debug_check_no_obj_freed+0x2a3/0x42e lib/debugobjects.c:817
> > >   slab_free_hook mm/slub.c:1426 [inline]
> > >   slab_free_freelist_hook+0xfb/0x140 mm/slub.c:1456
> > >   slab_free mm/slub.c:3003 [inline]
> > >   kfree+0xce/0x280 mm/slub.c:3958
> > >   rsi_probe+0xdf3/0x140d drivers/net/wireless/rsi/rsi_91x_sdio.c:1178
> > >   usb_probe_interface+0x31d/0x820 drivers/usb/core/driver.c:361
> > >   really_probe+0x2da/0xb10 drivers/base/dd.c:509
> > >   driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
> > >   __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
> > >   bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
> > >   __device_attach+0x223/0x3a0 drivers/base/dd.c:844
> > >   bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
> > >   device_add+0xad2/0x16e0 drivers/base/core.c:2106
> > >   usb_set_configuration+0xdf7/0x1740 drivers/usb/core/message.c:2021
> > >   generic_probe+0xa2/0xda drivers/usb/core/generic.c:210
> > >   usb_probe_device+0xc0/0x150 drivers/usb/core/driver.c:266
> > >   really_probe+0x2da/0xb10 drivers/base/dd.c:509
> > >   driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
> > >   __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
> > >   bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
> > >   __device_attach+0x223/0x3a0 drivers/base/dd.c:844
> > >   bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
> > >   device_add+0xad2/0x16e0 drivers/base/core.c:2106
> > >   usb_new_device.cold+0x537/0xccf drivers/usb/core/hub.c:2534
> > >   hub_port_connect drivers/usb/core/hub.c:5089 [inline]
> > >   hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
> > >   port_event drivers/usb/core/hub.c:5350 [inline]
> > >   hub_event+0x1398/0x3b00 drivers/usb/core/hub.c:5432
> > >   process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
> > >   worker_thread+0x9b/0xe20 kernel/workqueue.c:2415
> > >   kthread+0x313/0x420 kernel/kthread.c:253
> > >   ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
> > >
> > > ======================================================
> >
> > Let's try to test the below combined patch which fixes both the above
> > use-after-free issue and a second one which syzbot is likely to hit once
> > the first one is fixed. Now hopefully with a proper commit id:
> >
> > #syz test: https://github.com/google/kasan.git da06441bb4
> 
> Hi Johan,
> 
> The reproducer was found on commit d34f9519, so you need to specify
> that commit exactly when testing patches. Otherwise the reported
> result might be incorrect.

Yeah, I know but that commit is so old that it doesn't have a fix for a
another issue that syzbot would hit, and the patch I tried to test might
now even apply.

But, sure, I'll try that too after the reproducer is run on the latest
fuzzer commit (which do still have these bugs).

Johan