On Fri, Sep 20, 2019 at 12:02 PM Johan Hovold <johan@xxxxxxxxxx> wrote: > > On Fri, Sep 20, 2019 at 02:20:00AM -0700, syzbot wrote: > > Hello, > > > > syzbot has tested the proposed patch but the reproducer still triggered > > crash: > > KASAN: use-after-free Read in adu_interrupt_in_callback > > > > ================================================================== > > BUG: KASAN: use-after-free in __lock_acquire+0x302a/0x3b50 > > kernel/locking/lockdep.c:3753 > > Read of size 8 at addr ffff8881cd4d0358 by task kworker/0:6/3051 > > > > CPU: 0 PID: 3051 Comm: kworker/0:6 Not tainted 5.3.0-rc2+ #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > Google 01/01/2011 > > Workqueue: usb_hub_wq hub_event > > Call Trace: > > <IRQ> > > __dump_stack lib/dump_stack.c:77 [inline] > > dump_stack+0xca/0x13e lib/dump_stack.c:113 > > print_address_description+0x6a/0x32c mm/kasan/report.c:351 > > __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482 > > kasan_report+0xe/0x12 mm/kasan/common.c:612 > > __lock_acquire+0x302a/0x3b50 kernel/locking/lockdep.c:3753 > > lock_acquire+0x127/0x320 kernel/locking/lockdep.c:4412 > > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > > _raw_spin_lock_irqsave+0x32/0x50 kernel/locking/spinlock.c:159 > > adu_interrupt_in_callback+0x77/0x380 drivers/usb/misc/adutux.c:163 > > __usb_hcd_giveback_urb+0x1f2/0x470 drivers/usb/core/hcd.c:1757 > > usb_hcd_giveback_urb+0x368/0x420 drivers/usb/core/hcd.c:1822 > > dummy_timer+0x120f/0x2fa2 drivers/usb/gadget/udc/dummy_hcd.c:1965 > > call_timer_fn+0x179/0x650 kernel/time/timer.c:1322 > > expire_timers kernel/time/timer.c:1366 [inline] > > __run_timers kernel/time/timer.c:1685 [inline] > > __run_timers kernel/time/timer.c:1653 [inline] > > run_timer_softirq+0x5cc/0x14b0 kernel/time/timer.c:1698 > > __do_softirq+0x221/0x912 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:537 [inline] > > smp_apic_timer_interrupt+0x12f/0x500 arch/x86/kernel/apic/apic.c:1095 > > apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828 > > </IRQ> > > RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:85 [inline] > > RIP: 0010:console_unlock+0xa2a/0xc40 kernel/printk/printk.c:2471 > > Code: 00 89 ee 48 c7 c7 20 88 d3 86 e8 81 ad 03 00 65 ff 0d 72 a1 d9 7e e9 > > db f9 ff ff e8 70 a1 15 00 e8 1b cb 1a 00 ff 74 24 30 9d <e9> 18 fe ff ff > > e8 5c a1 15 00 48 8d 7d 08 48 89 f8 48 c1 e8 03 42 > > RSP: 0018:ffff8881cd20f200 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 > > RAX: 0000000000000007 RBX: 0000000000000200 RCX: 0000000000000006 > > RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8881ccd8d044 > > RBP: 0000000000000000 R08: ffff8881ccd8c800 R09: fffffbfff11acd91 > > R10: fffffbfff11acd90 R11: ffffffff88d66c87 R12: 0000000000000047 > > R13: dffffc0000000000 R14: ffffffff82909100 R15: ffffffff87077190 > > vprintk_emit+0x171/0x3e0 kernel/printk/printk.c:1986 > > vprintk_func+0x75/0x113 kernel/printk/printk_safe.c:386 > > printk+0xba/0xed kernel/printk/printk.c:2046 > > really_probe.cold+0x81/0x13a drivers/base/dd.c:616 > > driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709 > > __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816 > > bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 > > __device_attach+0x217/0x360 drivers/base/dd.c:882 > > bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 > > device_add+0xae6/0x16f0 drivers/base/core.c:2114 > > usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023 > > generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210 > > usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266 > > really_probe+0x281/0x650 drivers/base/dd.c:548 > > driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709 > > __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816 > > bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 > > __device_attach+0x217/0x360 drivers/base/dd.c:882 > > bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 > > device_add+0xae6/0x16f0 drivers/base/core.c:2114 > > usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536 > > hub_port_connect drivers/usb/core/hub.c:5098 [inline] > > hub_port_connect_change drivers/usb/core/hub.c:5213 [inline] > > port_event drivers/usb/core/hub.c:5359 [inline] > > hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441 > > process_one_work+0x92b/0x1530 kernel/workqueue.c:2269 > > worker_thread+0x96/0xe20 kernel/workqueue.c:2415 > > kthread+0x318/0x420 kernel/kthread.c:255 > > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > > > > Allocated by task 3051: > > save_stack+0x1b/0x80 mm/kasan/common.c:69 > > set_track mm/kasan/common.c:77 [inline] > > __kasan_kmalloc mm/kasan/common.c:487 [inline] > > __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:460 > > kmalloc include/linux/slab.h:552 [inline] > > kzalloc include/linux/slab.h:748 [inline] > > adu_probe+0x7d/0x6e0 drivers/usb/misc/adutux.c:660 > > usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361 > > really_probe+0x281/0x650 drivers/base/dd.c:548 > > driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709 > > __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816 > > bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 > > __device_attach+0x217/0x360 drivers/base/dd.c:882 > > bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 > > device_add+0xae6/0x16f0 drivers/base/core.c:2114 > > usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023 > > generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210 > > usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266 > > really_probe+0x281/0x650 drivers/base/dd.c:548 > > driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709 > > __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816 > > bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 > > __device_attach+0x217/0x360 drivers/base/dd.c:882 > > bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 > > device_add+0xae6/0x16f0 drivers/base/core.c:2114 > > usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536 > > hub_port_connect drivers/usb/core/hub.c:5098 [inline] > > hub_port_connect_change drivers/usb/core/hub.c:5213 [inline] > > port_event drivers/usb/core/hub.c:5359 [inline] > > hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441 > > process_one_work+0x92b/0x1530 kernel/workqueue.c:2269 > > worker_thread+0x96/0xe20 kernel/workqueue.c:2415 > > kthread+0x318/0x420 kernel/kthread.c:255 > > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > > > > Freed by task 3051: > > save_stack+0x1b/0x80 mm/kasan/common.c:69 > > set_track mm/kasan/common.c:77 [inline] > > __kasan_slab_free+0x130/0x180 mm/kasan/common.c:449 > > slab_free_hook mm/slub.c:1423 [inline] > > slab_free_freelist_hook mm/slub.c:1470 [inline] > > slab_free mm/slub.c:3012 [inline] > > kfree+0xe4/0x2f0 mm/slub.c:3953 > > adu_probe+0x5de/0x6e0 drivers/usb/misc/adutux.c:750 > > usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361 > > really_probe+0x281/0x650 drivers/base/dd.c:548 > > driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709 > > __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816 > > bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 > > __device_attach+0x217/0x360 drivers/base/dd.c:882 > > bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 > > device_add+0xae6/0x16f0 drivers/base/core.c:2114 > > usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023 > > generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210 > > usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266 > > really_probe+0x281/0x650 drivers/base/dd.c:548 > > driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709 > > __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816 > > bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 > > __device_attach+0x217/0x360 drivers/base/dd.c:882 > > bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 > > device_add+0xae6/0x16f0 drivers/base/core.c:2114 > > usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536 > > hub_port_connect drivers/usb/core/hub.c:5098 [inline] > > hub_port_connect_change drivers/usb/core/hub.c:5213 [inline] > > port_event drivers/usb/core/hub.c:5359 [inline] > > hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441 > > process_one_work+0x92b/0x1530 kernel/workqueue.c:2269 > > worker_thread+0x96/0xe20 kernel/workqueue.c:2415 > > kthread+0x318/0x420 kernel/kthread.c:255 > > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > > This looks like a separate issue, which should be fixed by a separate > patch. Not sure how to tell syzbot that. Dmitry? There is no way, but also no need. There is nothing it can do with that info. If you think it's a separate one and you fixed the first one, mail the patch with the first fix. Optionally, you can fix the second one as well, and then ask it to test a patch with 2 fixes (but you will need either to squash them or point to a git tree with both commits). > There's is indeed another bug in the driver, which could lead to crashes > in the completion handler after clearing the struct usb_device pointer, > but possibly also to the above use-after-free if a new device is probed > immediately after a disconnect. > > The below patch addresses both bugs, let's see if that helps. > > #syz test: https://github.com/google/kasan.git e96407b4 > > Johan > > From c68eda0c6aae5b233fbd583afbfd3ea15acbc62f Mon Sep 17 00:00:00 2001 > From: Johan Hovold <johan@xxxxxxxxxx> > Date: Thu, 19 Sep 2019 11:48:38 +0200 > Subject: [PATCH] USB: adutux: fix use-after-free on disconnect + more > > FIXME: separate stopping URBs > > The driver was clearing its struct usb_device pointer, which it uses as > an inverted disconnected flag, before deregistering the character device > and without serialising against racing release(). > > This could lead to a use-after-free if a racing release() callback > observes the cleared pointer and frees the driver data before > disconnect() is finished with it. > > This could also lead to NULL-pointer dereferences in a racing open(). > > Fixes: f08812d5eb8f ("USB: FIx locks and urb->status in adutux (updated)") > Reported-by: syzbot+0243cb250a51eeefb8cc@xxxxxxxxxxxxxxxxxxxxxxxxx > Cc: stable <stable@xxxxxxxxxxxxxxx> # 2.6.24 > Signed-off-by: Johan Hovold <johan@xxxxxxxxxx> > --- > drivers/usb/misc/adutux.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/usb/misc/adutux.c b/drivers/usb/misc/adutux.c > index 344d523b0502..a6996772745e 100644 > --- a/drivers/usb/misc/adutux.c > +++ b/drivers/usb/misc/adutux.c > @@ -762,14 +762,18 @@ static void adu_disconnect(struct usb_interface *interface) > > dev = usb_get_intfdata(interface); > > - mutex_lock(&dev->mtx); /* not interruptible */ > - dev->udev = NULL; /* poison */ > usb_deregister_dev(interface, &adu_class); > - mutex_unlock(&dev->mtx); > + > + usb_poison_urb(dev->interrupt_in_urb); > + usb_poison_urb(dev->interrupt_out_urb); > > mutex_lock(&adutux_mutex); > usb_set_intfdata(interface, NULL); > > + mutex_lock(&dev->mtx); /* not interruptible */ > + dev->udev = NULL; /* poison */ > + mutex_unlock(&dev->mtx); > + > /* if the device is not opened, then we clean up right now */ > if (!dev->open_count) > adu_delete(dev); > -- > 2.23.0 > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/20190920100233.GP30545%40localhost.
