Re: KASAN: out-of-bounds Read in hidraw_ioctl

[Andrey Konovalov]

On Fri, Aug 9, 2019 at 8:18 PM syzbot
<syzbot+f817d84b72194c4a5fe2@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    e96407b4 usb-fuzzer: main usb gadget fuzzer driver
> git tree:       https://github.com/google/kasan.git usb-fuzzer
> console output: https://syzkaller.appspot.com/x/log.txt?x=126120e2600000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=cfa2c18fb6a8068e
> dashboard link: https://syzkaller.appspot.com/bug?extid=f817d84b72194c4a5fe2
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+f817d84b72194c4a5fe2@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> ==================================================================
> BUG: KASAN: out-of-bounds in hidraw_ioctl+0x609/0xae0
> drivers/hid/hidraw.c:380
> Read of size 4 at addr ffff8881cb9fc018 by task syz-executor.1/3309
>
> CPU: 1 PID: 3309 Comm: syz-executor.1 Not tainted 5.3.0-rc2+ #25
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Call Trace:
>   __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
>   hidraw_ioctl+0x609/0xae0 drivers/hid/hidraw.c:380
>   vfs_ioctl fs/ioctl.c:46 [inline]
>   file_ioctl fs/ioctl.c:509 [inline]
>   do_vfs_ioctl+0xd2d/0x1330 fs/ioctl.c:696
>   ksys_ioctl+0x9b/0xc0 fs/ioctl.c:713
>   __do_sys_ioctl fs/ioctl.c:720 [inline]
>   __se_sys_ioctl fs/ioctl.c:718 [inline]
>   __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:718
>   do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296
>   entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x459829
> Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7
> 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
> ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007f877bde2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459829
> RDX: 0000000020001300 RSI: 0000000080044801 RDI: 0000000000000004
> RBP: 000000000075c118 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007f877bde36d4
> R13: 00000000004c2206 R14: 00000000004d5610 R15: 00000000ffffffff
>
> Allocated by task 2751:
>   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
>   slab_post_alloc_hook mm/slab.h:520 [inline]
>   slab_alloc_node mm/slub.c:2766 [inline]
>   __kmalloc_node_track_caller+0xd0/0x230 mm/slub.c:4361
>   __kmalloc_reserve.isra.0+0x39/0xe0 net/core/skbuff.c:141
>   __alloc_skb+0xef/0x5a0 net/core/skbuff.c:209
>   alloc_skb include/linux/skbuff.h:1055 [inline]
>   alloc_uevent_skb+0x7b/0x210 lib/kobject_uevent.c:289
>   uevent_net_broadcast_untagged lib/kobject_uevent.c:325 [inline]
>   kobject_uevent_net_broadcast lib/kobject_uevent.c:408 [inline]
>   kobject_uevent_env+0x8ee/0x1160 lib/kobject_uevent.c:592
>   device_del+0x6b2/0xb10 drivers/base/core.c:2298
>   usb_disconnect+0x4c3/0x8d0 drivers/usb/core/hub.c:2225
>   hub_port_connect drivers/usb/core/hub.c:4949 [inline]
>   hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
>   port_event drivers/usb/core/hub.c:5359 [inline]
>   hub_event+0x1454/0x3640 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 238:
>   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
>   skb_free_head+0x8b/0xa0 net/core/skbuff.c:591
>   skb_release_data+0x41f/0x7c0 net/core/skbuff.c:611
>   skb_release_all+0x46/0x60 net/core/skbuff.c:665
>   __kfree_skb net/core/skbuff.c:679 [inline]
>   consume_skb net/core/skbuff.c:838 [inline]
>   consume_skb+0xd9/0x320 net/core/skbuff.c:832
>   skb_free_datagram+0x16/0xf0 net/core/datagram.c:328
>   netlink_recvmsg+0x65e/0xee0 net/netlink/af_netlink.c:1996
>   sock_recvmsg_nosec net/socket.c:871 [inline]
>   sock_recvmsg net/socket.c:889 [inline]
>   sock_recvmsg+0xca/0x110 net/socket.c:885
>   ___sys_recvmsg+0x271/0x5a0 net/socket.c:2480
>   __sys_recvmsg+0xe9/0x1b0 net/socket.c:2537
>   do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296
>   entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> The buggy address belongs to the object at ffff8881cb9fc000
>   which belongs to the cache kmalloc-1k of size 1024
> The buggy address is located 24 bytes inside of
>   1024-byte region [ffff8881cb9fc000, ffff8881cb9fc400)
> The buggy address belongs to the page:
> page:ffffea00072e7f00 refcount:1 mapcount:0 mapping:ffff8881da002280
> index:0x0 compound_mapcount: 0
> flags: 0x200000000010200(slab|head)
> raw: 0200000000010200 dead000000000100 dead000000000122 ffff8881da002280
> raw: 0000000000000000 00000000000e000e 00000001ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
>   ffff8881cb9fbf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>   ffff8881cb9fbf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> > ffff8881cb9fc000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>                              ^
>   ffff8881cb9fc080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>   ffff8881cb9fc100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================

#syz dup: BUG: bad usercopy in hidraw_ioctl

>
>
> ---
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