Hi, i have found this warning in my vanilla 5.15.4 kernel's dmesg log: [ 87.687139] ------------[ cut here ]------------ [ 87.710799] WARNING: CPU: 1 PID: 1 at drivers/gpu/drm/ttm/ttm_bo.c:409 ttm_bo_release+0x1c/0x266 [ttm] [ 87.718965] Modules linked in: nf_nat_ftp nf_conntrack_ftp cfg80211 af_packet nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_tables ebtable_nat ebtable_broute ip6table_nat ip6table_mangle ip6table_raw ip6table_security iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c iptable_mangle iptable_raw iptable_security nfnetlink ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter bnep it87 hwmon_vid dm_mod dax snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio snd_hda_codec_hdmi snd_hda_intel uvcvideo videobuf2_vmalloc videobuf2_memops snd_intel_dspcfg snd_hda_codec snd_usb_audio snd_usbmidi_lib snd_hwdep videobuf2_v4l2 snd_virtuoso snd_oxygen_lib videobuf2_common btusb snd_mpu401_uart input_leds snd_hda_core videodev btbcm snd_rawmidi btintel joydev snd_seq mc led_class bluetooth ecdh_generic rfkill snd_seq_device ecc snd_pcm r8169 coretemp snd_hrtimer i2c_i801 psmouse [ 87.719024] i2c_smbus pcspkr kvm_intel realtek kvm snd_timer gpio_ich mdio_devres iTCO_wdt snd libphy mxm_wmi irqbypass soundcore tiny_power_button lpc_ich i7core_edac acpi_cpufreq button wmi nfsd auth_rpcgss nfs_acl lockd grace sunrpc binfmt_misc fuse configfs zram zsmalloc ip_tables x_tables ext4 crc32c_generic crc16 mbcache jbd2 hid_microsoft usbhid sr_mod cdrom sd_mod amdgpu uhci_hcd drm_ttm_helper ehci_pci ttm mfd_core ehci_hcd gpu_sched xhci_pci xhci_hcd i2c_algo_bit crc32c_intel serio_raw drm_kms_helper firewire_ohci ahci libahci pata_jmicron firewire_core libata crc_itu_t cfbfillrect syscopyarea cfbimgblt sysfillrect sysimgblt fb_sys_fops cfbcopyarea cec rc_core scsi_mod usbcore drm bsg scsi_common usb_common drm_panel_orientation_quirks ipmi_devintf ipmi_msghandler msr sha256_ssse3 sha256_generic ipv6 crc_ccitt [ 87.876267] CPU: 1 PID: 1 Comm: systemd Tainted: G I 5.15.4 #1 [ 87.882109] Hardware name: Gigabyte Technology Co., Ltd. EX58-UD3R/EX58-UD3R, BIOS FB 05/04/2009 [ 87.889800] RIP: 0010:ttm_bo_release+0x1c/0x266 [ttm] [ 87.893615] Code: 44 89 e0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 41 56 41 55 41 54 4c 8d a7 90 fe ff ff 55 53 83 7f 4c 00 48 89 fb 48 8b 6f e8 74 02 <0f> 0b 80 7b 18 00 48 8b 43 88 0f 85 ac 00 00 00 4c 8d 6b 90 49 39 [ 87.911829] RSP: 0018:ffffc90000023e00 EFLAGS: 00010202 [ 87.915886] RAX: 0000000000000001 RBX: ffff888123a449c8 RCX: 000000000000004c [ 87.921825] RDX: 00000000000001f3 RSI: ffffffffa02ee0e5 RDI: ffff888123a449c8 [ 87.927750] RBP: ffff88810d6652f0 R08: 0000000000000001 R09: 0000000000000003 [ 87.933869] R10: 0000000040000000 R11: ffff888109970600 R12: ffff888123a44858 [ 87.939767] R13: ffff888146e35ad0 R14: ffff888146dad6c0 R15: 0000000000000000 [ 87.945604] FS: 00007f901262ab40(0000) GS:ffff888343c40000(0000) knlGS:0000000000000000 [ 87.952390] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 87.956837] CR2: 000055d9edfa8fa0 CR3: 0000000102180000 CR4: 00000000000006e0 [ 87.962704] Call Trace: [ 87.963876] <TASK> [ 87.964742] amdgpu_bo_unref+0x15/0x1e [amdgpu] [ 87.968219] amdgpu_gem_object_free+0x2b/0x45 [amdgpu] [ 87.972135] drm_gem_dmabuf_release+0x11/0x1a [drm] [ 87.975792] dma_buf_release+0x36/0x7d [ 87.978363] __dentry_kill+0xf5/0x12f [ 87.980749] dput+0xfc/0x136 [ 87.982386] __fput+0x17a/0x1cc [ 87.984234] task_work_run+0x64/0x75 [ 87.986615] exit_to_user_mode_prepare+0x88/0x112 [ 87.990111] syscall_exit_to_user_mode+0x14/0x1f [ 87.993513] do_syscall_64+0x7a/0x80 [ 87.995873] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 87.999798] RIP: 0033:0x7f9013160fdb [ 88.002129] Code: 03 00 00 00 0f 05 48 3d 00 f0 ff ff 77 41 c3 48 83 ec 18 89 7c 24 0c e8 33 81 f8 ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 81 81 f8 ff 8b 44 [ 88.020215] RSP: 002b:00007ffda9891d20 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 [ 88.026698] RAX: 0000000000000000 RBX: 00007f901262a8f0 RCX: 00007f9013160fdb [ 88.032789] RDX: 0000000000000000 RSI: 000000055d9edfc6 RDI: 0000000000000069 [ 88.038864] RBP: 0000000000000069 R08: 0000000000000000 R09: 000000000000007f [ 88.045044] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 [ 88.051033] R13: 000055d9ecadd680 R14: 000055d9eca96719 R15: 000055d9edf412f0 [ 88.056868] </TASK> [ 88.057758] ---[ end trace bf3184763fd2083a ]--- I have seen a warning like this one in every dmesg log from 5.14.x onwards, and it is clearly still present in the 5.15.x series too. My GPU is a Radeon R7 360 (Bonaire). Cheers, Chris