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From: Andrey Konovalov <andreyknvl@google.com>
Date: Mon, 12 Dec 2016 21:32:35 +0100
Message-ID: <CAAeHK+wfVr0RVgSZDxwKkh1g=7uyYsbeevZBdYjhkv1eNRrm=w@mail.gmail.com>
Subject: Re: usb/gadget: warning in ep_write_iter/__alloc_pages_nodemask
To: Felipe Balbi <balbi@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Deepa Dinamani <deepa.kernel@gmail.com>,
        Michal Hocko <mhocko@suse.com>,
        Andrey Konovalov <andreyknvl@google.com>,
        Mathieu Laurendeau <mat.lau@laposte.net>, Bin Liu <b-liu@ti.com>,
        USB list <linux-usb@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Alan Stern <stern@rowland.harvard.edu>
Cc: syzkaller <syzkaller@googlegroups.com>,
        Dmitry Vyukov <dvyukov@google.com>, Kostya Serebryany <kcc@google.com>
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On Mon, Dec 12, 2016 at 9:31 PM, Andrey Konovalov <andreyknvl@google.com> wrote:
> Hi!
>
> While running the syzkaller fuzzer I've got the following error report.
>
> The issue is that the len argument is not checked for being too big.
>
> WARNING: CPU: 1 PID: 9935 at mm/page_alloc.c:3511
> __alloc_pages_nodemask+0x159c/0x1e20
> Kernel panic - not syncing: panic_on_warn set ...
>
> CPU: 1 PID: 9935 Comm: syz-executor0 Not tainted 4.9.0-rc7+ #34
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>  ffff88006949f2c8 ffffffff81f96b8a ffffffff00000200 1ffff1000d293dec
>  ffffed000d293de4 0000000000000a06 0000000041b58ab3 ffffffff8598b510
>  ffffffff81f968f8 0000000041b58ab3 ffffffff85942a58 ffffffff81432860
> Call Trace:
>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>  [<ffffffff81f96b8a>] dump_stack+0x292/0x398 lib/dump_stack.c:51
>  [<ffffffff8168c88e>] panic+0x1cb/0x3a9 kernel/panic.c:179
>  [<ffffffff812b80b4>] __warn+0x1c4/0x1e0 kernel/panic.c:542
>  [<ffffffff812b831c>] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
>  [<     inline     >] __alloc_pages_slowpath mm/page_alloc.c:3511
>  [<ffffffff816c08ac>] __alloc_pages_nodemask+0x159c/0x1e20 mm/page_alloc.c:3781
>  [<ffffffff817cde17>] alloc_pages_current+0x1c7/0x6b0 mm/mempolicy.c:2072
>  [<     inline     >] alloc_pages include/linux/gfp.h:469
>  [<ffffffff8172fd8f>] kmalloc_order+0x1f/0x70 mm/slab_common.c:1015
>  [<ffffffff8172fdff>] kmalloc_order_trace+0x1f/0x160 mm/slab_common.c:1026
>  [<     inline     >] kmalloc_large include/linux/slab.h:422
>  [<ffffffff817e01f0>] __kmalloc+0x210/0x2d0 mm/slub.c:3723
>  [<     inline     >] kmalloc include/linux/slab.h:495
>  [<ffffffff832262a7>] ep_write_iter+0x167/0xb50
> drivers/usb/gadget/legacy/inode.c:664
>  [<     inline     >] new_sync_write fs/read_write.c:499
>  [<ffffffff817fdcd3>] __vfs_write+0x483/0x760 fs/read_write.c:512
>  [<ffffffff817ff720>] vfs_write+0x170/0x4e0 fs/read_write.c:560
>  [<     inline     >] SYSC_write fs/read_write.c:607
>  [<ffffffff81803b2b>] SyS_write+0xfb/0x230 fs/read_write.c:599
>  [<ffffffff84f47ec1>] entry_SYSCALL_64_fastpath+0x1f/0xc2
> Dumping ftrace buffer:
>    (ftrace buffer empty)
> Kernel Offset: disabled

+syzkaller