bisecting fixing commit since 610bdbf6a174c9a91e34e276a9594114b44bef74 building syzkaller on 2c1f2513486f21d26b1942ce77ffc782677fbf4e testing commit 610bdbf6a174c9a91e34e276a9594114b44bef74 with gcc (GCC) 8.4.1 20210217 kernel signature: 8fcd4df0fb837c26c5419b08990b4a5cd6559946f8ea2c492990cf61f01364cd all runs: crashed: WARNING in drm_prime_destroy_file_private testing current HEAD 2d19be4653f5e74ed95560b69f94eb6791d49af3 testing commit 2d19be4653f5e74ed95560b69f94eb6791d49af3 with gcc (GCC) 8.4.1 20210217 kernel signature: 31e80c1ff46d1f7f93548ef3bd927058fa75b7a9278e0c5bbe8e6c8f1be154e3 all runs: crashed: WARNING in drm_prime_destroy_file_private revisions tested: 2, total time: 22m58.858635398s (build: 15m31.322564964s, test: 6m33.579881855s) the crash still happens on HEAD commit msg: Linux 4.19.177 crash: WARNING in drm_prime_destroy_file_private wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50 wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50 IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready ------------[ cut here ]------------ WARNING: CPU: 1 PID: 10042 at drivers/gpu/drm/drm_prime.c:982 drm_prime_destroy_file_private.cold.6+0xc/0x13 drivers/gpu/drm/drm_prime.c:982 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 10042 Comm: syz-executor.3 Not tainted 4.19.177-syzkaller #0 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+0x17c/0x226 lib/dump_stack.c:118 panic+0x1cd/0x375 kernel/panic.c:186 __warn.cold.7+0x1b/0x36 kernel/panic.c:541 report_bug+0x1a1/0x200 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] fixup_bug arch/x86/kernel/traps.c:173 [inline] do_error_trap+0x200/0x350 arch/x86/kernel/traps.c:296 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038 RIP: 0010:drm_prime_destroy_file_private.cold.6+0xc/0x13 drivers/gpu/drm/drm_prime.c:982 Code: 8b 45 c8 e9 cd 20 18 fc 48 c7 c7 a0 63 60 88 e8 5d 53 f6 ff 0f 0b 83 c8 ff e9 5d 26 18 fc 48 c7 c7 a0 63 60 88 e8 47 53 f6 ff <0f> 0b e9 97 30 18 fc 48 c7 c7 c0 68 60 88 e8 34 53 f6 ff 0f 0b e9 RSP: 0018:ffff8880917f7aa8 EFLAGS: 00010286 RAX: 0000000000000024 RBX: ffff88809da1ebe8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff88500500 RDI: ffffffff8bad7720 RBP: ffff8880917f7ab0 R08: ffffed1017464e99 R09: ffffed1017464e98 R10: ffffed1017464e98 R11: ffff8880ba3274c7 R12: ffff88823899e980 R13: ffff88809da1eb50 R14: ffff88823899e9a0 R15: ffffffff89f49140 drm_file_free.part.0+0x7ed/0xc30 drivers/gpu/drm/drm_file.c:257 drm_file_free drivers/gpu/drm/drm_file.c:215 [inline] drm_release+0x1ee/0x350 drivers/gpu/drm/drm_file.c:480 __fput+0x249/0x7f0 fs/file_table.c:278 ____fput+0x9/0x10 fs/file_table.c:309 task_work_run+0x108/0x180 kernel/task_work.c:113 get_signal+0x1352/0x1970 kernel/signal.c:2400 do_signal+0x87/0x1870 arch/x86/kernel/signal.c:821 exit_to_usermode_loop+0x159/0x1e0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x413/0x4e0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x465b09 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1ff62f2188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000020000140 RSI: 00000000c10c5541 RDI: 0000000000000003 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007fffee763baf R14: 00007f1ff62f2300 R15: 0000000000022000 Kernel Offset: disabled Rebooting in 86400 seconds..