bisecting fixing commit since 1752938529c614a8ed4432ecce6ebc95d3b87207
building syzkaller on 80910769fd1f04ef3263915865ffec0da1d7a421
testing commit 1752938529c614a8ed4432ecce6ebc95d3b87207 with gcc (GCC) 8.4.1 20210217
kernel signature: acb4f479a9ffe2240e24f9749ed1ead8e3e1cec66a04d25fc7800be935daf5ca
all runs: crashed: WARNING in drm_prime_destroy_file_private
testing current HEAD 3242aa3a635c0958671ee1e4b0958dcc7c4e5c79
testing commit 3242aa3a635c0958671ee1e4b0958dcc7c4e5c79 with gcc (GCC) 8.4.1 20210217
kernel signature: 83ce380a23f260551f3fea2915550ac304176c94f06079bb58384024e533cdf7
all runs: crashed: WARNING in drm_prime_destroy_file_private
revisions tested: 2, total time: 21m3.641164906s (build: 13m54.744733416s, test: 6m13.780287569s)
the crash still happens on HEAD
commit msg: Linux 4.14.222
crash: WARNING in drm_prime_destroy_file_private
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
Bluetooth: hci3 command 0x0419 tx timeout
Bluetooth: hci4 command 0x0419 tx timeout
Bluetooth: hci5 command 0x0419 tx timeout
------------[ cut here ]------------
WARNING: CPU: 1 PID: 10052 at drivers/gpu/drm/drm_prime.c:898 drm_prime_destroy_file_private+0x32/0x40 drivers/gpu/drm/drm_prime.c:899
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 10052 Comm: syz-executor.1 Not tainted 4.14.222-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x14b/0x1e7 lib/dump_stack.c:58
 panic+0x1b0/0x358 kernel/panic.c:183
 __warn.cold.7+0x25/0x25 kernel/panic.c:547
 report_bug+0x1a1/0x200 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [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:drm_prime_destroy_file_private+0x32/0x40 drivers/gpu/drm/drm_prime.c:898
RSP: 0018:ffff8880932f7d40 EFLAGS: 00010282
RAX: ffff88809b444710 RBX: ffff888094c33478 RCX: 1ffff11016061515
RDX: 1ffff1101298669f RSI: ffff8880b030a888 RDI: ffff888094c334f8
RBP: ffff8880932f7d48 R08: ffff8880b030a8a8 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8882384960c0
R13: ffff8882384960e0 R14: ffff888094c333e0 R15: ffffffff894dbb00
 drm_release+0xa45/0xf40 drivers/gpu/drm/drm_file.c:427
 __fput+0x232/0x740 fs/file_table.c:210
 ____fput+0x9/0x10 fs/file_table.c:244
 task_work_run+0xe5/0x170 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x14a/0x190 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x416/0x5b0 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x465b69
RSP: 002b:00007fdfe2bbb188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 000000000056bf60 RCX: 0000000000465b69
RDX: 0000000020000140 RSI: 00000000c10c5541 RDI: 0000000000000003
RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffe5ca0544f R14: 00007fdfe2bbb300 R15: 0000000000022000
Kernel Offset: disabled
Rebooting in 86400 seconds..