------------[ cut here ]------------ WARNING: CPU: 0 PID: 22522 at drivers/gpu/drm/vkms/vkms_gem.c:37 vkms_gem_free_object+0x85/0xa0 drivers/gpu/drm/vkms/vkms_gem.c:37 Modules linked in: CPU: 0 PID: 22522 Comm: syz-executor.4 Not tainted 5.9.0-rc5-next-20200921-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:vkms_gem_free_object+0x85/0xa0 drivers/gpu/drm/vkms/vkms_gem.c:37 Code: 00 75 2b e8 cd 19 ee fc 48 8d bd 30 02 00 00 e8 c1 c9 d2 fc 48 89 ef e8 29 57 a4 ff 48 89 ef 5d e9 30 04 2f fd e8 ab 19 ee fc <0f> 0b eb a8 e8 a2 19 ee fc 0f 0b eb cc e8 69 7e 2f fd eb bb e8 62 RSP: 0018:ffffc90016187c18 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffffffff84870e00 RCX: ffffffff842b8918 RDX: ffff8880a5dc21c0 RSI: ffffffff84870e85 RDI: ffff8880a829fac0 RBP: ffff8880a829f800 R08: 0000000000000001 R09: ffff8880a829f803 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888218354c30 R13: ffff8880a829f808 R14: ffff8880a829f928 R15: ffff88808f84b000 FS: 00000000036a8940(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000296da98 CR3: 00000000a115e000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: drm_gem_object_free drivers/gpu/drm/drm_gem.c:990 [inline] kref_put include/linux/kref.h:65 [inline] __drm_gem_object_put include/drm/drm_gem.h:370 [inline] drm_gem_object_put include/drm/drm_gem.h:383 [inline] drm_gem_object_handle_put_unlocked+0x3ac/0x420 drivers/gpu/drm/drm_gem.c:238 drm_gem_object_release_handle+0xf9/0x1b0 drivers/gpu/drm/drm_gem.c:260 idr_for_each+0x113/0x220 lib/idr.c:208 drm_gem_release+0x22/0x30 drivers/gpu/drm/drm_gem.c:947 drm_file_free.part.0+0x866/0xcb0 drivers/gpu/drm/drm_file.c:282 drm_file_free drivers/gpu/drm/drm_file.c:251 [inline] drm_close_helper.isra.0+0x17d/0x1f0 drivers/gpu/drm/drm_file.c:309 drm_release+0x1e6/0x530 drivers/gpu/drm/drm_file.c:494 __fput+0x285/0x920 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:141 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:163 [inline] exit_to_user_mode_prepare+0x1e2/0x1f0 kernel/entry/common.c:190 syscall_exit_to_user_mode+0x7a/0x2c0 kernel/entry/common.c:265 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x416f41 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007ffc48296260 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 0000000000416f41 RDX: 0000000000000000 RSI: 00000000000000b0 RDI: 0000000000000006 RBP: 0000000000000001 R08: 000000006bfc60b3 R09: 0000000000000000 R10: 00007ffc48296350 R11: 0000000000000293 R12: 0000000001191038 R13: 000000000006f995 R14: ffffffffffffffff R15: 000000000118cf4c