WARNING in kobject_get

Status: public: reported syz repro on 2019/04/14 09:28
Reported-by: syzbot+8d80429dbe6b5b579dec@syzkaller.appspotmail.com
First crash: 3041d, last: 2556d
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-44 WARNING in kobject_get -1 syz 3 2652d 2690d 0/2 public: reported syz repro on 2019/04/14 08:52

Sample crash report:
input: syz1 as /devices/virtual/input/input925
input: syz1 as /devices/virtual/input/input926
input: syz1 as /devices/virtual/input/input927
input: syz1 as /devices/virtual/input/input930
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5916 at ./include/linux/kref.h:46 kref_get include/linux/kref.h:46 [inline]
WARNING: CPU: 1 PID: 5916 at ./include/linux/kref.h:46 kobject_get lib/kobject.c:596 [inline]
WARNING: CPU: 1 PID: 5916 at ./include/linux/kref.h:46 kobject_get+0xd9/0xf0 lib/kobject.c:589
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 5916 Comm: syz-executor.4 Not tainted 4.9.170+ #48
 ffff8801d7c2f7e0 ffffffff81b4fb21 0000000000000000 ffffffff82a39ba0
 00000000ffffffff 0000000000000001 0000000000000009 ffff8801d7c2f8c0
 ffffffff813f966a 0000000041b58ab3 ffffffff82e2ef22 ffffffff813f9491
Call Trace:
 [<00000000df0473b9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<00000000df0473b9>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<000000004ae6b03d>] panic+0x1d9/0x3bd kernel/panic.c:180
 [<00000000575d62a8>] __warn.cold+0x2f/0x2f kernel/panic.c:546
 [<00000000a37666d1>] warn_slowpath_null+0x2d/0x40 kernel/panic.c:589
 [<0000000026aa0d4a>] kref_get include/linux/kref.h:46 [inline]
 [<0000000026aa0d4a>] kobject_get lib/kobject.c:596 [inline]
 [<0000000026aa0d4a>] kobject_get+0xd9/0xf0 lib/kobject.c:589
 [<00000000aa473459>] cdev_get+0x54/0xa0 fs/char_dev.c:333
 [<000000007ad900e5>] chrdev_open+0xb0/0x630 fs/char_dev.c:378
 [<000000006ff651e4>] do_dentry_open+0x422/0xd20 fs/open.c:772
 [<00000000ec35da36>] vfs_open+0x105/0x230 fs/open.c:885
 [<00000000d2df36d3>] do_last fs/namei.c:3457 [inline]
 [<00000000d2df36d3>] path_openat+0xbf5/0x2f60 fs/namei.c:3581
 [<000000000685d81e>] do_filp_open+0x1a1/0x280 fs/namei.c:3615
 [<00000000dbbb7f99>] do_sys_open+0x2f0/0x610 fs/open.c:1078
 [<00000000308a015f>] SYSC_open fs/open.c:1096 [inline]
 [<00000000308a015f>] SyS_open+0x2d/0x40 fs/open.c:1091
 [<0000000094711945>] do_syscall_64+0x1ad/0x570 arch/x86/entry/common.c:285
 [<00000000375bbfd4>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/04/28 18:25 https://android.googlesource.com/kernel/common android-4.9 6cf3205cc803 b617407b .config console log report syz ci-android-49-kasan-gce-root
2018/10/23 07:03 https://android.googlesource.com/kernel/common android-4.9 826f32857c23 ecb386fe .config console log report syz ci-android-49-kasan-gce
2019/08/24 12:20 https://android.googlesource.com/kernel/common android-4.9 8fe428403e30 78ded196 .config console log report syz ci-android-49-kasan-gce-386
2019/05/20 12:02 https://android.googlesource.com/kernel/common android-4.9 8fe428403e30 5a4461b0 .config console log report syz ci-android-49-kasan-gce-386
2019/08/26 22:26 https://android.googlesource.com/kernel/common android-4.9 476e7ea6e7a1 d21c5d9d .config console log report ci-android-49-kasan-gce-root
2019/07/24 01:30 https://android.googlesource.com/kernel/common android-4.9 cd46375d4f59 de453f34 .config console log report ci-android-49-kasan-gce-root
2019/01/01 07:11 https://android.googlesource.com/kernel/common android-4.9 9f23a833fdcd 3d85f48c .config console log report ci-android-49-kasan-gce-root
2018/09/07 03:42 https://android.googlesource.com/kernel/common android-4.9 dcae9fa1319b e30d3b52 .config console log report ci-android-49-kasan-gce-root
2018/04/28 09:25 https://android.googlesource.com/kernel/common android-4.9 71fce1edd26d d5a5d045 .config console log report ci-android-49-kasan-gce-root
* Struck through repros no longer work on HEAD.