syzbot


WARNING in kernfs_new_node

Status: fixed on 2020/05/10 10:41
Subsystems: kernfs
[Documentation on labels]
Reported-by: syzbot+499aea72daa2cea73cb7@syzkaller.appspotmail.com
Fix commit: 810507fe6fd5 locking/lockdep: Reuse freed chain_hlocks entries
First crash: 1780d, last: 1552d
Cause bisection: introduced by (bisect log) :
commit 726e41097920a73e4c7c33385dcc0debb1281e18
Author: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Tue Jul 10 00:29:10 2018 +0000

  drivers: core: Remove glue dirs from sysfs earlier

Crash: general protection fault in kernfs_add_one (log)
Repro: C syz .config
  
Fix bisection: fixed by (bisect log) :
commit 810507fe6fd5ff3de429121adff49523fabb643a
Author: Waiman Long <longman@redhat.com>
Date: Thu Feb 6 15:24:08 2020 +0000

  locking/lockdep: Reuse freed chain_hlocks entries

  
Discussions (1)
Title Replies (including bot) Last reply
WARNING in kernfs_new_node 2 (4) 2020/04/16 16:20
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in kernfs_new_node (2) kernfs 1 42d 38d 0/27 upstream: reported on 2024/05/08 04:35
Fix bisection attempts (4)
Created Duration User Patch Repo Result
2020/04/16 07:28 4h12m bisect fix upstream job log (1)
2020/03/16 20:59 20m bisect fix upstream job log (0) log
2020/02/09 07:44 23m bisect fix upstream job log (0) log
2020/01/10 07:22 21m bisect fix upstream job log (0) log

Sample crash report:
debugfs: Directory 'hci3' with parent 'bluetooth' already present!
------------[ cut here ]------------
WARNING: CPU: 0 PID: 9903 at fs/kernfs/dir.c:493 kernfs_get fs/kernfs/dir.c:493 [inline]
WARNING: CPU: 0 PID: 9903 at fs/kernfs/dir.c:493 kernfs_new_node+0x155/0x180 fs/kernfs/dir.c:700
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 9903 Comm: syz-executor126 Not tainted 5.3.0-rc2+ #59
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+0x1d8/0x2f8 lib/dump_stack.c:113
 panic+0x29b/0x7d9 kernel/panic.c:219
 __warn+0x22f/0x230 kernel/panic.c:576
 report_bug+0x190/0x290 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap+0xd7/0x440 arch/x86/kernel/traps.c:272
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1026
RIP: 0010:kernfs_get fs/kernfs/dir.c:493 [inline]
RIP: 0010:kernfs_new_node+0x155/0x180 fs/kernfs/dir.c:700
Code: d2 ff 4c 89 23 4c 89 f0 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 69 47 98 ff 48 c7 c7 6d b9 7a 88 31 c0 e8 9e a6 80 ff <0f> 0b eb 8e 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c 67 ff ff ff 4c
RSP: 0018:ffff88808d96f6f0 EFLAGS: 00010246
RAX: 0000000000000024 RBX: 0000000000000000 RCX: d31929014df6e300
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffff88808d96f728 R08: ffffffff816068e4 R09: fffffbfff11fbdfd
R10: fffffbfff11fbdfd R11: 0000000000000000 R12: ffff88809377b620
R13: ffff8880982858c0 R14: ffff888095d39460 R15: ffff88821b70d150
 kernfs_create_dir_ns+0x44/0x130 fs/kernfs/dir.c:1022
 sysfs_create_dir_ns+0x161/0x310 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:89 [inline]
 kobject_add_internal+0x459/0xd50 lib/kobject.c:255
 kobject_add_varg lib/kobject.c:390 [inline]
 kobject_add+0x138/0x200 lib/kobject.c:442
 device_add+0x508/0x1570 drivers/base/core.c:2065
 hci_register_dev+0x331/0x720 net/bluetooth/hci_core.c:3307
 __vhci_create_device drivers/bluetooth/hci_vhci.c:124 [inline]
 vhci_create_device+0x2f3/0x530 drivers/bluetooth/hci_vhci.c:148
 vhci_get_user drivers/bluetooth/hci_vhci.c:204 [inline]
 vhci_write+0x3ac/0x440 drivers/bluetooth/hci_vhci.c:284
 call_write_iter include/linux/fs.h:1870 [inline]
 new_sync_write fs/read_write.c:483 [inline]
 __vfs_write+0x617/0x7d0 fs/read_write.c:496
 vfs_write+0x275/0x590 fs/read_write.c:558
 ksys_write+0x16b/0x2a0 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:620
 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441d39
Code: e8 4c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd7e3026c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441d39
RDX: 0000000000000002 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffdbb1414ac R09: 00007ffdbb1414ac
R10: 00007ffdbb1414ac R11: 0000000000000246 R12: 0000000000014cb3
R13: 0000000000402a30 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/08/01 20:19 upstream 1e78030e5e5b 835dffe7 .config console log report syz C ci-upstream-kasan-gce-smack-root
2019/08/01 19:43 upstream 1e78030e5e5b 835dffe7 .config console log report ci-upstream-kasan-gce-smack-root
* Struck through repros no longer work on HEAD.