KASAN: use-after-free Read in str_to_user

Status: auto-closed as invalid on 2020/08/17 19:40
Subsystems: input
[Documentation on labels]
Reported-by: syzbot+b1f387654f49043c302b@syzkaller.appspotmail.com
First crash: 2538d, last: 2306d
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
Reminder: 52 active syzbot reports in usb subsystem 4 (4) 2019/09/19 19:01
KASAN: use-after-free Read in str_to_user 0 (1) 2019/09/03 12:08

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in strlen+0x79/0x90 lib/string.c:544
Read of size 1 at addr ffff8881ad63e208 by task syz-executor.5/6115

CPU: 0 PID: 6115 Comm: syz-executor.5 Not tainted 5.6.0-rc7-syzkaller #0
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+0xef/0x16e lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x314 mm/kasan/report.c:374
 __kasan_report.cold+0x37/0x77 mm/kasan/report.c:506
 kasan_report+0xe/0x20 mm/kasan/common.c:641
 strlen+0x79/0x90 lib/string.c:544
 strlen include/linux/string.h:303 [inline]
 str_to_user+0x27/0x90 drivers/input/evdev.c:780
 evdev_do_ioctl drivers/input/evdev.c:1183 [inline]
 evdev_ioctl_handler+0x130a/0x19f0 drivers/input/evdev.c:1281
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x11a/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770
 do_syscall_64+0xb6/0x5a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c829
Code: 0d 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f49009c0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e3dc0 RCX: 000000000045c829
RDX: 00000000200000c0 RSI: 0000000080404507 RDI: 0000000000000005
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000002cc R14: 00000000004c51d9 R15: 00007f49009c16d4

Allocated by task 3138:
 save_stack+0x1b/0x80 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:515 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:488
 kmalloc include/linux/slab.h:560 [inline]
 kzalloc include/linux/slab.h:669 [inline]
 usb_get_configuration+0x124/0x3a20 drivers/usb/core/config.c:882
 usb_enumerate_device drivers/usb/core/hub.c:2381 [inline]
 usb_new_device+0x2f9/0x450 drivers/usb/core/hub.c:2517
 hub_port_connect drivers/usb/core/hub.c:5195 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5335 [inline]
 port_event drivers/usb/core/hub.c:5481 [inline]
 hub_event+0x21cb/0x4300 drivers/usb/core/hub.c:5563
 process_one_work+0x94b/0x1620 kernel/workqueue.c:2266
 worker_thread+0x96/0xe20 kernel/workqueue.c:2412
 kthread+0x318/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Freed by task 3138:
 save_stack+0x1b/0x80 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:337 [inline]
 __kasan_slab_free+0x117/0x160 mm/kasan/common.c:476
 slab_free_hook mm/slub.c:1444 [inline]
 slab_free_freelist_hook mm/slub.c:1477 [inline]
 slab_free mm/slub.c:3034 [inline]
 kfree+0xd5/0x300 mm/slub.c:3995
 usb_destroy_configuration+0x49f/0x5f0 drivers/usb/core/config.c:850
 usb_release_dev+0x3e/0x100 drivers/usb/core/usb.c:418
 device_release+0x71/0x200 drivers/base/core.c:1371
 kobject_cleanup lib/kobject.c:693 [inline]
 kobject_release lib/kobject.c:722 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x256/0x550 lib/kobject.c:739
 put_device+0x1b/0x30 drivers/base/core.c:2599
 hub_port_connect drivers/usb/core/hub.c:5046 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5335 [inline]
 port_event drivers/usb/core/hub.c:5481 [inline]
 hub_event+0x1a1d/0x4300 drivers/usb/core/hub.c:5563
 process_one_work+0x94b/0x1620 kernel/workqueue.c:2266
 process_scheduled_works kernel/workqueue.c:2328 [inline]
 worker_thread+0x7ab/0xe20 kernel/workqueue.c:2414
 kthread+0x318/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8881ad63e000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 520 bytes inside of
 1024-byte region [ffff8881ad63e000, ffff8881ad63e400)
The buggy address belongs to the page:
page:ffffea0006b58e00 refcount:1 mapcount:0 mapping:ffff8881da002280 index:0x0 compound_mapcount: 0
flags: 0x200000000010200(slab|head)
raw: 0200000000010200 dead000000000100 dead000000000122 ffff8881da002280
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881ad63e100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881ad63e180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881ad63e200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff8881ad63e280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881ad63e300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (39):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/04/19 19:39 https://github.com/google/kasan.git usb-fuzzer 0fa84af850a4 6dfd45e1 .config console log report ci2-upstream-usb
2020/04/18 17:11 https://github.com/google/kasan.git usb-fuzzer 0fa84af850a4 365fba24 .config console log report ci2-upstream-usb
2020/04/17 06:42 https://github.com/google/kasan.git usb-fuzzer 0fa84af850a4 c743fcb3 .config console log report ci2-upstream-usb
2020/04/12 04:17 https://github.com/google/kasan.git usb-fuzzer 0fa84af850a4 a8c6a3f8 .config console log report ci2-upstream-usb
2020/04/11 09:39 https://github.com/google/kasan.git usb-fuzzer 0fa84af850a4 a8c6a3f8 .config console log report ci2-upstream-usb
2020/04/01 13:55 https://github.com/google/kasan.git usb-fuzzer 0fa84af850a4 a34e2c33 .config console log report ci2-upstream-usb
2020/03/30 06:05 https://github.com/google/kasan.git usb-fuzzer 0fa84af850a4 05736b29 .config console log report ci2-upstream-usb
2020/03/29 04:12 https://github.com/google/kasan.git usb-fuzzer 0fa84af850a4 05736b29 .config console log report ci2-upstream-usb
2020/03/29 01:49 https://github.com/google/kasan.git usb-fuzzer 0fa84af850a4 05736b29 .config console log report ci2-upstream-usb
2020/03/25 09:13 https://github.com/google/kasan.git usb-fuzzer e17994d1e7b1 41f049cc .config console log report ci2-upstream-usb
2020/03/24 15:29 https://github.com/google/kasan.git usb-fuzzer e17994d1e7b1 33e14df3 .config console log report ci2-upstream-usb
2020/03/24 11:22 https://github.com/google/kasan.git usb-fuzzer e17994d1e7b1 33e14df3 .config console log report ci2-upstream-usb
2020/03/24 08:23 https://github.com/google/kasan.git usb-fuzzer e17994d1e7b1 33e14df3 .config console log report ci2-upstream-usb
2020/03/23 09:46 https://github.com/google/kasan.git usb-fuzzer e17994d1e7b1 78267cec .config console log report ci2-upstream-usb
2020/03/23 07:23 https://github.com/google/kasan.git usb-fuzzer e17994d1e7b1 78267cec .config console log report ci2-upstream-usb
2020/03/20 15:46 https://github.com/google/kasan.git usb-fuzzer e17994d1e7b1 2c31c529 .config console log report ci2-upstream-usb
2020/03/19 14:38 https://github.com/google/kasan.git usb-fuzzer d6ff8147a51c 2c31c529 .config console log report ci2-upstream-usb
2020/03/19 09:34 https://github.com/google/kasan.git usb-fuzzer d6ff8147a51c 2c31c529 .config console log report ci2-upstream-usb
2020/03/18 08:07 https://github.com/google/kasan.git usb-fuzzer d6ff8147a51c 97bc55ce .config console log report ci2-upstream-usb
2020/03/17 19:43 https://github.com/google/kasan.git usb-fuzzer d6ff8147a51c 749688d2 .config console log report ci2-upstream-usb
2020/03/12 01:34 https://github.com/google/kasan.git usb-fuzzer d6ff8147a51c d850e9d0 .config console log report ci2-upstream-usb
2020/02/23 10:53 https://github.com/google/kasan.git usb-fuzzer 307a2623c9d7 2c36e7a7 .config console log report ci2-upstream-usb
2020/02/15 04:02 https://github.com/google/kasan.git usb-fuzzer 7f0cd6c7c423 5d7b90f1 .config console log report ci2-upstream-usb
2020/02/06 04:46 https://github.com/google/kasan.git usb-fuzzer e5cd56e94edd 662cf49a .config console log report ci2-upstream-usb
2020/02/05 16:34 https://github.com/google/kasan.git usb-fuzzer e5cd56e94edd 662cf49a .config console log report ci2-upstream-usb
2020/02/04 05:47 https://github.com/google/kasan.git usb-fuzzer cd234325a5f1 93e5e335 .config console log report ci2-upstream-usb
2020/01/29 05:45 https://github.com/google/kasan.git usb-fuzzer cd234325a5f1 c8e81ce4 .config console log report ci2-upstream-usb
2020/01/28 11:08 https://github.com/google/kasan.git usb-fuzzer cd234325a5f1 56cd6c9b .config console log report ci2-upstream-usb
2020/01/25 12:49 https://github.com/google/kasan.git usb-fuzzer cd234325a5f1 2e95ab33 .config console log report ci2-upstream-usb
2020/01/04 02:50 https://github.com/google/kasan.git usb-fuzzer ecdf2214f472 68256974 .config console log report ci2-upstream-usb
2020/01/02 18:30 https://github.com/google/kasan.git usb-fuzzer ecdf2214f472 25a0186e .config console log report ci2-upstream-usb
2019/12/28 20:25 https://github.com/google/kasan.git usb-fuzzer ecdf2214f472 af6b8ef8 .config console log report ci2-upstream-usb
2019/12/18 13:30 https://github.com/google/kasan.git usb-fuzzer d533c9925862 64ca0a37 .config console log report ci2-upstream-usb
2019/10/15 19:13 https://github.com/google/kasan.git usb-fuzzer 22be26f76193 b5268b89 .config console log report ci2-upstream-usb
2019/09/15 14:34 https://github.com/google/kasan.git usb-fuzzer f0df5c1be1e9 32d59357 .config console log report ci2-upstream-usb
2019/09/12 16:00 https://github.com/google/kasan.git usb-fuzzer f0df5c1be1e9 0b7672ee .config console log report ci2-upstream-usb
2019/09/07 18:03 https://github.com/google/kasan.git usb-fuzzer f0df5c1be1e9 a60cb4cd .config console log report ci2-upstream-usb
2019/09/07 13:55 https://github.com/google/kasan.git usb-fuzzer f0df5c1be1e9 a60cb4cd .config console log report ci2-upstream-usb
2019/08/31 17:05 https://github.com/google/kasan.git usb-fuzzer eea39f24f4a5 bad3cce2 .config console log report ci2-upstream-usb
* Struck through repros no longer work on HEAD.