bisecting fixing commit since c7150cd2fa8c831c8a2ddd27bce3ac2a3372c93d
building syzkaller on 429d8a6becba0a60e99331e293e6117597e9e530
testing commit c7150cd2fa8c831c8a2ddd27bce3ac2a3372c93d with gcc (GCC) 8.4.1 20210217
kernel signature: e9ff26ae3df92d445a91d16a8e69ddd6b8ea971a4c70e1759a6dcdb23654bd44
all runs: crashed: WARNING in drm_prime_destroy_file_private
testing current HEAD 958e517f4e16952e9a2e2d58fd32d28ae4e23dda
testing commit 958e517f4e16952e9a2e2d58fd32d28ae4e23dda with gcc (GCC) 8.4.1 20210217
kernel signature: 67478d361c09a5aec3ba8f9ba0b958cdd485b16aa8bb79cf7fd14c01bb225d26
all runs: crashed: WARNING in drm_prime_destroy_file_private
revisions tested: 2, total time: 26m21.045966817s (build: 18m53.61354819s, test: 6m39.782381155s)
the crash still happens on HEAD
commit msg: Linux 4.14.230
crash: WARNING in drm_prime_destroy_file_private
Bluetooth: hci0 command 0x0419 tx timeout
Bluetooth: hci1 command 0x0419 tx timeout
Bluetooth: hci4 command 0x0419 tx timeout
Bluetooth: hci3 command 0x0419 tx timeout
------------[ cut here ]------------
WARNING: CPU: 1 PID: 9773 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: 9773 Comm: syz-executor.3 Not tainted 4.14.230-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:ffff88809ab1fab8 EFLAGS: 00010282
RAX: ffff88809a9b4810 RBX: ffff888096bb98f8 RCX: 1ffff11012c92d8d
RDX: 1ffff11012d7732f RSI: ffff888096496c48 RDI: ffff888096bb9978
RBP: ffff88809ab1fac0 R08: ffff888096496c68 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880af1bc580
R13: ffff8880af1bc5a0 R14: ffff888096bb9860 R15: ffffffff894dd200
 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
 get_signal+0x1447/0x1a90 kernel/signal.c:2234
 do_signal+0x7f/0x18b0 arch/x86/kernel/signal.c:792
 exit_to_usermode_loop+0x11e/0x190 arch/x86/entry/common.c:160
 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: 0033:0x465f69
RSP: 002b:00007fb6ce1b1188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 000000000056bf60 RCX: 0000000000465f69
RDX: 0000000020000140 RSI: 00000000c10c5541 RDI: 0000000000000003
RBP: 00000000004bfa8f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007fff0311d21f R14: 00007fb6ce1b1300 R15: 0000000000022000
Kernel Offset: disabled
Rebooting in 86400 seconds..