On Tue, Dec 6, 2016 at 1:28 PM, Andrey Konovalov <andreyknvl@xxxxxxxxxx> wrote: > 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. It seems that I was wrong. Still see both use-after-free and warnings. > > 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
