Re: KASAN: use-after-free Read in v4l2_ioctl

[Andrey Konovalov <andreyknvl@google.com>]

On Tue, Aug 13, 2019 at 2:28 PM Andrey Konovalov <andreyknvl@google.com> wrote:
>
> On Sun, Apr 14, 2019 at 10:06 PM syzbot
> <syzbot+d587871cd33a9bc7c086@syzkaller.appspotmail.com> wrote:
> >
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit:    9a33b369 usb-fuzzer: main usb gadget fuzzer driver
> > git tree:       https://github.com/google/kasan/tree/usb-fuzzer
> > console output: https://syzkaller.appspot.com/x/log.txt?x=137d8a2d200000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=23e37f59d94ddd15
> > dashboard link: https://syzkaller.appspot.com/bug?extid=d587871cd33a9bc7c086
> > compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13e878f3200000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=102432e3200000
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+d587871cd33a9bc7c086@syzkaller.appspotmail.com
> >
> > usb 6-1: USB disconnect, device number 19
> > radio-raremono 6-1:0.210: Thanko's Raremono disconnected
> > radio-si470x 2-1:0.210: could not find interrupt in endpoint
> > radio-si470x 3-1:0.210: could not find interrupt in endpoint
> > ==================================================================
> > BUG: KASAN: use-after-free in v4l2_ioctl+0x187/0x1a0
> > drivers/media/v4l2-core/v4l2-dev.c:362
> > Read of size 8 at addr ffff88809b3645e0 by task v4l_id/5799
> > radio-si470x 4-1:0.210: could not find interrupt in endpoint
> >
> > CPU: 0 PID: 5799 Comm: v4l_id Not tainted 5.1.0-rc4-319354-g9a33b36 #3
> > radio-si470x: probe of 4-1:0.210 failed with error -5
> > 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+0xe8/0x16e lib/dump_stack.c:113
> >   print_address_description+0x6c/0x236 mm/kasan/report.c:187
> > radio-si470x: probe of 2-1:0.210 failed with error -5
> >   kasan_report.cold+0x1a/0x3c mm/kasan/report.c:317
> >   v4l2_ioctl+0x187/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:362
> >   vfs_ioctl fs/ioctl.c:46 [inline]
>
> #syz fix: media: radio-raremono: change devm_k*alloc to k*alloc

#syz dup: KASAN: use-after-free Read in v4l2_release

>
> >   file_ioctl fs/ioctl.c:509 [inline]
> >   do_vfs_ioctl+0xced/0x12f0 fs/ioctl.c:696
> > usb 5-1: new high-speed USB device number 19 using dummy_hcd
> > radio-si470x: probe of 3-1:0.210 failed with error -5
> >   ksys_ioctl+0xa0/0xc0 fs/ioctl.c:713
> >   __do_sys_ioctl fs/ioctl.c:720 [inline]
> >   __se_sys_ioctl fs/ioctl.c:718 [inline]
> >   __x64_sys_ioctl+0x74/0xb0 fs/ioctl.c:718
> >   do_syscall_64+0xcf/0x4f0 arch/x86/entry/common.c:290
> >   entry_SYSCALL_64_after_hwframe+0x49/0xbe
> > RIP: 0033:0x7f435c835347
> > Code: 90 90 90 48 8b 05 f1 fa 2a 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff
> > ff c3 90 90 90 90 90 90 90 90 90 90 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff
> > ff 73 01 c3 48 8b 0d c1 fa 2a 00 31 d2 48 29 c2 64
> > radio-raremono 2-1:0.210: Thanko's Raremono connected: (10C4:818A)
> > RSP: 002b:00007ffeca71fda8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
> > RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f435c835347
> > RDX: 00007ffeca71fdb0 RSI: 0000000080685600 RDI: 0000000000000003
> > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
> > R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400884
> > R13: 00007ffeca71ff00 R14: 0000000000000000 R15: 0000000000000000
> >
> > Allocated by task 12:
> >   set_track mm/kasan/common.c:87 [inline]
> >   __kasan_kmalloc mm/kasan/common.c:497 [inline]
> >   __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:470
> >   slab_post_alloc_hook mm/slab.h:437 [inline]
> >   slab_alloc_node mm/slub.c:2756 [inline]
> >   __kmalloc_node_track_caller+0xf3/0x320 mm/slub.c:4372
> >   alloc_dr drivers/base/devres.c:103 [inline]
> >   devm_kmalloc+0x8c/0x190 drivers/base/devres.c:793
> >   devm_kzalloc include/linux/device.h:679 [inline]
> >   usb_raremono_probe+0x34/0x235 drivers/media/radio/radio-raremono.c:298
> > radio-raremono 3-1:0.210: Thanko's Raremono connected: (10C4:818A)
> >   usb_probe_interface+0x31d/0x820 drivers/usb/core/driver.c:361
> >   really_probe+0x2da/0xb10 drivers/base/dd.c:509
> > radio-raremono 4-1:0.210: Thanko's Raremono connected: (10C4:818A)
> >   driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
> >   __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
> >   bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
> >   __device_attach+0x223/0x3a0 drivers/base/dd.c:844
> > usb 1-1: new high-speed USB device number 19 using dummy_hcd
> >   bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
> >   device_add+0xad2/0x16e0 drivers/base/core.c:2106
> >   usb_set_configuration+0xdf7/0x1740 drivers/usb/core/message.c:2021
> >   generic_probe+0xa2/0xda drivers/usb/core/generic.c:210
> >   usb_probe_device+0xc0/0x150 drivers/usb/core/driver.c:266
> >   really_probe+0x2da/0xb10 drivers/base/dd.c:509
> >   driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
> >   __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
> >   bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
> >   __device_attach+0x223/0x3a0 drivers/base/dd.c:844
> >   bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
> > usb 5-1: Using ep0 maxpacket: 8
> >   device_add+0xad2/0x16e0 drivers/base/core.c:2106
> >   usb_new_device.cold+0x537/0xccf drivers/usb/core/hub.c:2534
> >   hub_port_connect drivers/usb/core/hub.c:5089 [inline]
> >   hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
> >   port_event drivers/usb/core/hub.c:5350 [inline]
> >   hub_event+0x138e/0x3b00 drivers/usb/core/hub.c:5432
> >   process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
> > radio-raremono 2-1:0.210: raremono_cmd_main failed (-71)
> >   process_scheduled_works kernel/workqueue.c:2331 [inline]
> >   worker_thread+0x7b0/0xe20 kernel/workqueue.c:2417
> > radio-raremono 4-1:0.210: raremono_cmd_main failed (-71)
> >   kthread+0x313/0x420 kernel/kthread.c:253
> >   ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
> >
> > Freed by task 12:
> > radio-raremono 2-1:0.210: V4L2 device registered as radio33
> >   set_track mm/kasan/common.c:87 [inline]
> >   __kasan_slab_free+0x130/0x180 mm/kasan/common.c:459
> > radio-raremono 4-1:0.210: V4L2 device registered as radio34
> >   slab_free_hook mm/slub.c:1429 [inline]
> >   slab_free_freelist_hook+0x5e/0x140 mm/slub.c:1456
> >   slab_free mm/slub.c:3003 [inline]
> >   kfree+0xce/0x290 mm/slub.c:3958
> >   release_nodes+0x4ac/0x920 drivers/base/devres.c:508
> >   devres_release_all+0x79/0xc8 drivers/base/devres.c:529
> >   __device_release_driver drivers/base/dd.c:1086 [inline]
> >   device_release_driver_internal+0x23a/0x4f0 drivers/base/dd.c:1113
> >   bus_remove_device+0x302/0x5c0 drivers/base/bus.c:556
> >   device_del+0x467/0xb90 drivers/base/core.c:2269
> >   usb_disable_device+0x242/0x790 drivers/usb/core/message.c:1235
> >   usb_disconnect+0x298/0x870 drivers/usb/core/hub.c:2197
> >   hub_port_connect drivers/usb/core/hub.c:4940 [inline]
> >   hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
> >   port_event drivers/usb/core/hub.c:5350 [inline]
> >   hub_event+0xcd2/0x3b00 drivers/usb/core/hub.c:5432
> >   process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
> >   process_scheduled_works kernel/workqueue.c:2331 [inline]
> >   worker_thread+0x7b0/0xe20 kernel/workqueue.c:2417
> >   kthread+0x313/0x420 kernel/kthread.c:253
> >   ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
> >
> > The buggy address belongs to the object at ffff88809b364400
> >   which belongs to the cache kmalloc-4k of size 4096
> > The buggy address is located 480 bytes inside of
> >   4096-byte region [ffff88809b364400, ffff88809b365400)
> > The buggy address belongs to the page:
> > page:ffffea00026cd800 count:1 mapcount:0 mapping:ffff88812c3f4600 index:0x0
> > compound_mapcount: 0
> > flags: 0xfff00000010200(slab|head)
> > raw: 00fff00000010200 dead000000000100 dead000000000200 ffff88812c3f4600
> > radio-raremono 3-1:0.210: raremono_cmd_main failed (-71)
> > raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
> > radio-raremono 3-1:0.210: V4L2 device registered as radio35
> > page dumped because: kasan: bad access detected
> >
> > Memory state around the buggy address:
> >   ffff88809b364480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> >   ffff88809b364500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > > ffff88809b364580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> >                                                         ^
> >   ffff88809b364600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> >   ffff88809b364680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ==================================================================
> >
> >
> > ---
> > This bug is generated by a bot. It may contain errors.
> > See https://goo.gl/tpsmEJ for more information about syzbot.
> > syzbot engineers can be reached at syzkaller@googlegroups.com.
> >
> > syzbot will keep track of this bug report. See:
> > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> > syzbot can test patches for this bug, for details see:
> > https://goo.gl/tpsmEJ#testing-patches
> >
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