bisecting fixing commit since 01364dad1d4577e27a57729d41053f661bb8a5b9
building syzkaller on 6d25c5a09d4115832b286e56380045283679ce52
testing commit 01364dad1d4577e27a57729d41053f661bb8a5b9 with gcc (GCC) 8.1.0
kernel signature: 1a860c6f8c11f2f042db486fca5d5b6a54ca073d3054f6b70164dc2f46a9ddc5
run #0: crashed: WARNING in sysfs_warn_dup
run #1: crashed: WARNING in corrupted
run #2: crashed: WARNING in sysfs_warn_dup
run #3: crashed: WARNING in sysfs_warn_dup
run #4: crashed: WARNING in sysfs_warn_dup
run #5: crashed: WARNING in sysfs_warn_dup
run #6: crashed: WARNING in sysfs_warn_dup
run #7: crashed: WARNING in sysfs_warn_dup
run #8: crashed: WARNING in sysfs_warn_dup
run #9: crashed: WARNING in sysfs_warn_dup
testing current HEAD a41ba30d9df20fe141c92aacbb56b6b077f19716
testing commit a41ba30d9df20fe141c92aacbb56b6b077f19716 with gcc (GCC) 8.1.0
kernel signature: ac6ad0cf35e1217dcec2bf8c584611b190cafd3672e1579de4a79133a36d3048
all runs: crashed: WARNING in sysfs_warn_dup
revisions tested: 2, total time: 23m22.904886486s (build: 16m44.030412331s, test: 6m4.162657519s)
the crash still happens on HEAD
commit msg: Linux 4.14.181
crash: WARNING in sysfs_warn_dup
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
------------[ cut here ]------------
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
WARNING: CPU: 1 PID: 7944 at fs/sysfs/dir.c:31 sysfs_warn_dup.cold.4+0x12/0x32 fs/sysfs/dir.c:30
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 7944 Comm: syz-executor.0 Not tainted 4.14.181-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xf7/0x13b lib/dump_stack.c:58
 panic+0x1b0/0x358 kernel/panic.c:183
 __warn.cold.8+0x25/0x2c kernel/panic.c:547
 report_bug+0x1a4/0x1f3 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 do_error_trap+0x1bd/0x310 arch/x86/kernel/traps.c:295
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:964
RIP: 0010:sysfs_warn_dup.cold.4+0x12/0x32 fs/sysfs/dir.c:30
RSP: 0018:ffff88809251f738 EFLAGS: 00010282
RAX: 0000000000000048 RBX: ffff88809c84e340 RCX: 0000000000000000
RDX: 0000000000000048 RSI: ffffffff86cbeaa0 RDI: ffffed10124a3ede
RBP: ffff88809251f750 R08: ffff88809b818aa8 R09: 0000000000000000
R10: 0000000000000000 R11: dffffc0000000000 R12: ffff8882192660e0
R13: ffff88809fe71d40 R14: ffff8880a6340200 R15: ffff88809bf641d0
 sysfs_create_dir_ns+0x108/0x1b0 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:71 [inline]
 kobject_add_internal+0x252/0x7d0 lib/kobject.c:229
 kobject_add_varg lib/kobject.c:364 [inline]
 kobject_init_and_add+0xc8/0x110 lib/kobject.c:436
 gfs2_sys_fs_add+0x185/0x440 fs/gfs2/sys.c:652
 fill_super+0x1235/0x2350 fs/gfs2/ops_fstype.c:1118
 gfs2_mount+0x3f5/0x4bb fs/gfs2/ops_fstype.c:1321
 mount_fs+0x7f/0x269 fs/super.c:1237
 vfs_kern_mount.part.33+0x58/0x3c0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0x36b/0x26a0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xb8/0xd0 fs/namespace.c:3072
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45f29a
RSP: 002b:00007f0e952ffa68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f0e953006d4 RCX: 000000000045f29a
RDX: 00007f0e952ffae0 RSI: 00000000200003c0 RDI: 00007f0e952ffb00
RBP: 000000000076bf00 R08: 00007f0e952ffb40 R09: 00007f0e952ffae0
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000bde R14: 00000000004cdfcc R15: 000000000076bf0c
Kernel Offset: disabled
Rebooting in 86400 seconds..