On Mon, Dec 5, 2016 at 8:31 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Mon, 5 Dec 2016, Andrey Konovalov wrote: > >> Hi! >> >> I've got the following error report while running the syzkaller fuzzer. >> >> On commit 3c49de52d5647cda8b42c4255cf8a29d1e22eff5 (Dec 2). >> >> BUG: KASAN: use-after-free in gadgetfs_setup+0x208a/0x20e0 at addr >> ffff88003dfe5bf2 >> Read of size 2 by task syz-executor0/22994 >> CPU: 3 PID: 22994 Comm: syz-executor0 Not tainted 4.9.0-rc7+ #16 >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 >> ffff88006df06a18 ffffffff81f96aba ffffffffe0528500 1ffff1000dbe0cd6 >> ffffed000dbe0cce ffff88006df068f0 0000000041b58ab3 ffffffff8598b4c8 >> ffffffff81f96828 1ffff1000dbe0ccd ffff88006df06708 ffff88006df06748 >> Call Trace: >> <IRQ> [ 201.343209] [< inline >] __dump_stack lib/dump_stack.c:15 >> <IRQ> [ 201.343209] [<ffffffff81f96aba>] dump_stack+0x292/0x398 >> lib/dump_stack.c:51 >> [<ffffffff817e4dec>] kasan_object_err+0x1c/0x70 mm/kasan/report.c:159 >> [< inline >] print_address_description mm/kasan/report.c:197 >> [<ffffffff817e5080>] kasan_report_error+0x1f0/0x4e0 mm/kasan/report.c:286 >> [< inline >] kasan_report mm/kasan/report.c:306 >> [<ffffffff817e562a>] __asan_report_load_n_noabort+0x3a/0x40 >> mm/kasan/report.c:337 >> [< inline >] config_buf drivers/usb/gadget/legacy/inode.c:1298 >> [<ffffffff8322c8fa>] gadgetfs_setup+0x208a/0x20e0 >> drivers/usb/gadget/legacy/inode.c:1368 >> [<ffffffff830fdcd0>] dummy_timer+0x11f0/0x36d0 >> drivers/usb/gadget/udc/dummy_hcd.c:1858 >> [<ffffffff814807c1>] call_timer_fn+0x241/0x800 kernel/time/timer.c:1308 >> [< inline >] expire_timers kernel/time/timer.c:1348 >> [<ffffffff81482de6>] __run_timers+0xa06/0xec0 kernel/time/timer.c:1641 >> [<ffffffff814832c1>] run_timer_softirq+0x21/0x80 kernel/time/timer.c:1654 >> [<ffffffff84f4af8b>] __do_softirq+0x2fb/0xb63 kernel/softirq.c:284 >> [< inline >] invoke_softirq kernel/softirq.c:364 >> [<ffffffff812d3b8e>] irq_exit+0x19e/0x1d0 kernel/softirq.c:405 >> [< inline >] exiting_irq arch/x86/include/asm/apic.h:659 >> [<ffffffff84f4a59b>] smp_apic_timer_interrupt+0x7b/0xa0 >> arch/x86/kernel/apic/apic.c:960 >> [<ffffffff84f4964c>] apic_timer_interrupt+0x8c/0xa0 >> arch/x86/entry/entry_64.S:489 >> <EOI> [ 201.343209] [<ffffffff84f472f9>] ? >> _raw_spin_unlock_irqrestore+0x119/0x1a0 >> [<ffffffff8136f9e4>] try_to_wake_up+0x174/0x1160 kernel/sched/core.c:2099 >> [< inline >] wake_up_process kernel/sched/core.c:2165 >> [<ffffffff81370a7a>] wake_up_q+0x8a/0xe0 kernel/sched/core.c:469 >> [<ffffffff814cc6de>] futex_wake+0x5be/0x6c0 kernel/futex.c:1453 >> [<ffffffff814d41dd>] do_futex+0x11bd/0x1f00 kernel/futex.c:3219 >> [< inline >] SYSC_futex kernel/futex.c:3275 >> [<ffffffff814d521c>] SyS_futex+0x2fc/0x400 kernel/futex.c:3243 >> [<ffffffff84f47ec1>] entry_SYSCALL_64_fastpath+0x1f/0xc2 > > Can you test whether the patch below fixes this problem? Hi Alan, Yes, I believe it does. It also seems to fix the warnings in dummy_free_request() I've been getting. Thanks! > > Alan Stern > > > > Index: usb-4.x/drivers/usb/gadget/legacy/inode.c > =================================================================== > --- usb-4.x.orig/drivers/usb/gadget/legacy/inode.c > +++ usb-4.x/drivers/usb/gadget/legacy/inode.c > @@ -1762,6 +1762,10 @@ dev_config (struct file *fd, const char > } > spin_unlock_irq(&dev->lock); > > + /* Registered but not yet bound to a UDC driver? */ > + if (dev->gadget_registered) > + return -EIO; > + > if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) > return -EINVAL; > > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
