syzbot


KASAN: use-after-free Read in string

Status: auto-closed as invalid on 2019/10/24 04:08
Reported-by: syzbot+e353ae815c9bbec69f81@syzkaller.appspotmail.com
First crash: 1821d, last: 1813d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 KASAN: use-after-free Read in string 1 1813d 1813d 0/1 auto-closed as invalid on 2019/10/23 10:48
upstream KASAN: use-after-free Read in string input C 247 1808d 2048d 12/26 fixed on 2019/06/14 18:22

Sample crash report:
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
==================================================================
BUG: KASAN: use-after-free in string+0x208/0x230 lib/vsprintf.c:604
Read of size 1 at addr ffff8880a03b7680 by task syz-executor.2/4725

CPU: 1 PID: 4725 Comm: syz-executor.2 Not tainted 4.19.36 #4
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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
 string+0x208/0x230 lib/vsprintf.c:604
 vsnprintf+0x980/0x19b0 lib/vsprintf.c:2293
 add_uevent_var+0x14d/0x310 lib/kobject_uevent.c:659
 input_dev_uevent+0x163/0x890 drivers/input/input.c:1594
 dev_uevent+0x312/0x580 drivers/base/core.c:1008
 kobject_uevent_env+0x487/0x1030 lib/kobject_uevent.c:547
 kobject_uevent+0x20/0x26 lib/kobject_uevent.c:636
 kobject_cleanup lib/kobject.c:649 [inline]
 kobject_release lib/kobject.c:691 [inline]
 kref_put include/linux/kref.h:70 [inline]
 kobject_put.cold+0x177/0x2ec lib/kobject.c:708
 put_device+0x20/0x30 drivers/base/core.c:2030
 input_put_device include/linux/input.h:349 [inline]
 evdev_free+0x51/0x70 drivers/input/evdev.c:369
 device_release+0x7d/0x210 drivers/base/core.c:891
 kobject_cleanup lib/kobject.c:662 [inline]
 kobject_release lib/kobject.c:691 [inline]
 kref_put include/linux/kref.h:70 [inline]
 kobject_put.cold+0x28f/0x2ec lib/kobject.c:708
 cdev_default_release+0x41/0x50 fs/char_dev.c:607
 kobject_cleanup lib/kobject.c:662 [inline]
 kobject_release lib/kobject.c:691 [inline]
 kref_put include/linux/kref.h:70 [inline]
 kobject_put.cold+0x28f/0x2ec lib/kobject.c:708
 cdev_put.part.0+0x39/0x50 fs/char_dev.c:368
 cdev_put+0x20/0x30 fs/char_dev.c:366
 __fput+0x75d/0x8b0 fs/file_table.c:281
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x412b61
Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 e4 1a 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007fff1d795140 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000412b61
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000001 R08: 00000000d697ed4a R09: ffffffffffffffff
R10: 00007fff1d795220 R11: 0000000000000293 R12: 000000000073c900
R13: 000000000073c900 R14: 0000000000178138 R15: 000000000073bf0c

Allocated by task 4742:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc mm/kasan/kasan.c:553 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531
 __do_kmalloc mm/slab.c:3727 [inline]
 __kmalloc_track_caller+0x159/0x750 mm/slab.c:3742
 kstrndup+0x5f/0xf0 mm/util.c:98
 uinput_dev_setup+0x1d4/0x310 drivers/input/misc/uinput.c:475
 uinput_ioctl_handler.isra.0+0x493/0x1c60 drivers/input/misc/uinput.c:886
 uinput_ioctl+0x4a/0x60 drivers/input/misc/uinput.c:1049
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 4765:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcf/0x230 mm/slab.c:3822
 uinput_destroy_device+0xf8/0x250 drivers/input/misc/uinput.c:311
 uinput_ioctl_handler.isra.0+0x15f/0x1c60 drivers/input/misc/uinput.c:882
 uinput_ioctl+0x4a/0x60 drivers/input/misc/uinput.c:1049
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880a03b7680
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8880a03b7680, ffff8880a03b76a0)
The buggy address belongs to the page:
page:ffffea000280edc0 count:1 mapcount:0 mapping:ffff88812c3f01c0 index:0xffff8880a03b7fc1
flags: 0x1fffc0000000100(slab)
raw: 01fffc0000000100 ffffea000268ab08 ffffea00026c40c8 ffff88812c3f01c0
raw: ffff8880a03b7fc1 ffff8880a03b7000 000000010000003f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a03b7580: fb fb fb fb fc fc fc fc 00 00 06 fc fc fc fc fc
 ffff8880a03b7600: fb fb fb fb fc fc fc fc 00 00 fc fc fc fc fc fc
>ffff8880a03b7680: fb fb fb fb fc fc fc fc 00 00 06 fc fc fc fc fc
                   ^
 ffff8880a03b7700: 05 fc fc fc fc fc fc fc 00 00 01 fc fc fc fc fc
 ffff8880a03b7780: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
protocol 88fb is buggy, dev hsr_slave_1
protocol 88fb is buggy, dev hsr_slave_0

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/04/27 04:07 linux-4.19.y c98875d930e9 b617407b .config console log report ci2-linux-4-19
2019/04/18 14:41 linux-4.19.y 4b0e041c9dad b0e8efcb .config console log report ci2-linux-4-19
* Struck through repros no longer work on HEAD.