Hi guys! I'm getting the following warn on 4.15-rc1, on GTX 560 Ti:
[ 9.430433] nouveau 0000:01:00.0: NVIDIA GF114 (0ce000a1) ... [ 9.585172] nouveau 0000:01:00.0: bios: version 70.24.2e.00.02 ... [ 9.772204] nouveau 0000:01:00.0: fb: 1024 MiB GDDR5 [ 9.777342] ------------[ cut here ]------------ [ 9.782106] refcount_t: increment on 0; use-after-free. [ 9.787522] WARNING: CPU: 0 PID: 3 at lib/refcount.c:153 refcount_inc+0x30/0x50 [ 9.795060] Modules linked in: sha256_generic cfg80211(+) rfkill snd_usb_audio snd_usbmidi_lib nouveau(+) video ttm [ 9.805756] CPU: 0 PID: 3 Comm: kworker/0:0 Not tainted 4.15.0-rc1-debug-ubsan-00020-gf4707a916107 #1 [ 9.815215] Hardware name: System manufacturer System Product Name/M4A77T, BIOS 2401 05/18/2011 [ 9.824420] Workqueue: events work_for_cpu_fn [ 9.828915] task: ffff880226110c80 task.stack: ffffc90000c80000 [ 9.830647] cfg80211: Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7' [ 9.841681] RIP: 0010:refcount_inc+0x30/0x50 [ 9.846093] RSP: 0018:ffffc90000c83808 EFLAGS: 00010296 [ 9.851458] RAX: 000000000000002b RBX: 0000000000000000 RCX: 0000000000000000 [ 9.858763] RDX: 0000000000000001 RSI: 0000000000000082 RDI: ffffffff8378eb8c [ 9.866051] RBP: ffff88021f103fd0 R08: 0000000000000199 R09: ffff8800000bd500 [ 9.873330] R10: 0000000000000000 R11: ffffffff82289a80 R12: 0000000000000000 [ 9.880621] R13: ffff8802103a69e0 R14: ffff88021f103fe0 R15: ffff88021f103fe0 [ 9.887909] FS: 0000000000000000(0000) GS:ffff88022fc00000(0000) knlGS:0000000000000000 [ 9.896230] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 9.902117] CR2: 0000560476ba0000 CR3: 0000000225232000 CR4: 00000000000006f0 [ 9.909417] Call Trace: [ 9.912106] nv50_instobj_acquire+0x123/0x1c0 [nouveau] [ 9.917565] ? nvbios_rd08+0x1b/0x70 [nouveau] [ 9.922239] nvkm_instobj_new+0x1e3/0x520 [nouveau] [ 9.927353] ? nvbios_rd08+0x1b/0x70 [nouveau] [ 9.932017] ? nvbios_pll_parse+0x8d7/0xcf0 [nouveau] [ 9.937218] ? kmem_cache_alloc+0x1f0/0x2d0 [ 9.941624] nvkm_memory_new+0x4b/0xc0 [nouveau] [ 9.946461] ? nvkm_longopt+0x17/0x60 [nouveau] [ 9.951208] gf100_fb_oneinit+0x7b/0x1c0 [nouveau] [ 9.956218] nvkm_fb_oneinit+0x89/0x2e0 [nouveau] [ 9.961144] nvkm_subdev_init+0x92/0x600 [nouveau] [ 9.966085] ? ktime_get+0x64/0x110 [ 9.969815] nvkm_device_init+0x169/0x2a0 [nouveau] [ 9.974922] nvkm_udevice_init+0x7e/0xf0 [nouveau] [ 9.979924] nvkm_object_init+0x6a/0x2e0 [nouveau] [ 9.984932] nvkm_ioctl_new+0x198/0x430 [nouveau] [ 9.989846] ? nvif_vmm_init+0x340/0x340 [nouveau] [ 9.994864] ? nvkm_udevice_rd08+0x90/0x90 [nouveau] [ 10.000056] nvkm_ioctl+0x21e/0x5a0 [nouveau] [ 10.004548] ? yield_to+0x2b2/0x370 [ 10.008257] nvif_object_init+0xef/0x1b0 [nouveau] [ 10.013281] nvif_device_init+0x9/0x40 [nouveau] [ 10.018136] nouveau_cli_init+0x234/0x12f0 [nouveau] [ 10.023253] ? idr_alloc_cyclic+0x6c/0x110 [ 10.027487] ? _cond_resched+0x1d/0x80 [ 10.031366] ? kmem_cache_alloc+0x1f0/0x2d0 [ 10.035790] nouveau_drm_load+0x71/0xec0 [nouveau] [ 10.040735] drm_dev_register+0x1b4/0x330 [ 10.044872] ? pci_enable_device_flags+0x155/0x200 [ 10.049806] drm_get_pci_dev+0xde/0x2c0 [ 10.053874] nouveau_drm_probe+0x1b9/0x240 [nouveau] [ 10.058986] ? __pm_runtime_resume+0x68/0xb0 [ 10.063409] local_pci_probe+0x5e/0xf0 [ 10.067300] work_for_cpu_fn+0x10/0x30 [ 10.071183] process_one_work+0x21a/0x670 [ 10.075325] worker_thread+0x256/0x500 [ 10.079208] ? manage_workers+0x1e0/0x1e0 [ 10.083362] kthread+0x169/0x220 [ 10.086730] ? kthread_create_worker_on_cpu+0x40/0x40 [ 10.091933] ret_from_fork+0x1f/0x30 [ 10.095655] Code: ff 84 c0 74 02 5b c3 0f b6 1d 59 b2 a6 01 80 fb 01 77 1c 83 e3 01 75 ed 48 c7 c7 c8 f1 3f 82 c6 05 41 b2 a6 01 01 e8 50 02 8d ff <0f> ff 5b c3 0f b6 f3 48 c7 c7 00 16 c7 82 e8 dd 81 0d 00 eb d3 [ 10.114909] ---[ end trace 08f29138ff4259e6 ]--- [ 10.119703] hpet1: lost 21 rtc interrupts [ 10.125534] ------------[ cut here ]------------ [ 10.130326] refcount_t: underflow; use-after-free. [ 10.135292] WARNING: CPU: 0 PID: 3 at lib/refcount.c:281 refcount_dec_not_one+0x68/0x90 [ 10.143540] Modules linked in: sha256_generic cfg80211 rfkill snd_usb_audio snd_usbmidi_lib nouveau(+) video ttm [ 10.153956] CPU: 0 PID: 3 Comm: kworker/0:0 Tainted: G W 4.15.0-rc1-debug-ubsan-00020-gf4707a916107 #1 [ 10.164719] Hardware name: System manufacturer System Product Name/M4A77T, BIOS 2401 05/18/2011 [ 10.173929] Workqueue: events work_for_cpu_fn [ 10.178423] task: ffff880226110c80 task.stack: ffffc90000c80000 [ 10.184488] RIP: 0010:refcount_dec_not_one+0x68/0x90 [ 10.189580] RSP: 0018:ffffc90000c837f0 EFLAGS: 00010286 [ 10.194946] RAX: 0000000000000026 RBX: 0000000000000000 RCX: 0000000000000000 [ 10.202232] RDX: 0000000000000001 RSI: 0000000000000092 RDI: ffffffff8378eb8c [ 10.209512] RBP: ffff8802103a69e0 R08: 0000000000000199 R09: ffff8800000b9040 [ 10.216801] R10: 0000000000000000 R11: ffffffff82289a80 R12: ffff8802103a69e0 [ 10.224090] R13: ffffffffa025dc20 R14: ffff88021f103f80 R15: ffffffffa0368e60 [ 10.231362] FS: 0000000000000000(0000) GS:ffff88022fc00000(0000) knlGS:0000000000000000 [ 10.239679] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 10.245569] CR2: 0000560476ba0000 CR3: 0000000225232000 CR4: 00000000000006f0 [ 10.252862] Call Trace: [ 10.255433] refcount_dec_and_mutex_lock+0x18/0x70 [ 10.260450] nv50_instobj_release+0x69/0x1a0 [nouveau] [ 10.265834] nvkm_instobj_new+0x219/0x520 [nouveau] [ 10.270935] ? nvbios_rd08+0x1b/0x70 [nouveau] [ 10.275598] ? nvbios_pll_parse+0x8d7/0xcf0 [nouveau] [ 10.280807] ? kmem_cache_alloc+0x1f0/0x2d0 [ 10.285205] nvkm_memory_new+0x4b/0xc0 [nouveau] [ 10.290042] ? nvkm_longopt+0x17/0x60 [nouveau] [ 10.294808] gf100_fb_oneinit+0x7b/0x1c0 [nouveau] [ 10.299818] nvkm_fb_oneinit+0x89/0x2e0 [nouveau] [ 10.304733] nvkm_subdev_init+0x92/0x600 [nouveau] [ 10.309667] ? ktime_get+0x64/0x110 [ 10.313394] nvkm_device_init+0x169/0x2a0 [nouveau] [ 10.318512] nvkm_udevice_init+0x7e/0xf0 [nouveau] [ 10.323524] nvkm_object_init+0x6a/0x2e0 [nouveau] [ 10.328539] nvkm_ioctl_new+0x198/0x430 [nouveau] [ 10.333464] ? nvif_vmm_init+0x340/0x340 [nouveau] [ 10.338506] ? nvkm_udevice_rd08+0x90/0x90 [nouveau] [ 10.343691] nvkm_ioctl+0x21e/0x5a0 [nouveau] [ 10.348190] ? yield_to+0x2b2/0x370 [ 10.351891] nvif_object_init+0xef/0x1b0 [nouveau] [ 10.356914] nvif_device_init+0x9/0x40 [nouveau] [ 10.361761] nouveau_cli_init+0x234/0x12f0 [nouveau] [ 10.366876] ? idr_alloc_cyclic+0x6c/0x110 [ 10.371120] ? _cond_resched+0x1d/0x80 [ 10.375000] ? kmem_cache_alloc+0x1f0/0x2d0 [ 10.379405] nouveau_drm_load+0x71/0xec0 [nouveau] [ 10.384340] drm_dev_register+0x1b4/0x330 [ 10.388488] ? pci_enable_device_flags+0x155/0x200 [ 10.393411] drm_get_pci_dev+0xde/0x2c0 [ 10.397482] nouveau_drm_probe+0x1b9/0x240 [nouveau] [ 10.402583] ? __pm_runtime_resume+0x68/0xb0 [ 10.407001] local_pci_probe+0x5e/0xf0 [ 10.410890] work_for_cpu_fn+0x10/0x30 [ 10.414780] process_one_work+0x21a/0x670 [ 10.418925] worker_thread+0x256/0x500 [ 10.422816] ? manage_workers+0x1e0/0x1e0 [ 10.426967] kthread+0x169/0x220 [ 10.430328] ? kthread_create_worker_on_cpu+0x40/0x40 [ 10.435524] ret_from_fork+0x1f/0x30 [ 10.439246] Code: da eb ea 31 c0 eb eb 0f b6 1d ce b0 a6 01 80 fb 01 77 2c 83 e3 01 75 d5 48 c7 c7 f8 f1 3f 82 c6 05 b6 b0 a6 01 01 e8 c8 00 8d ff <0f> ff eb be 31 f6 48 c7 c7 a0 14 c7 82 e8 a6 7d 0d 00 eb 91 0f [ 10.458480] ---[ end trace 08f29138ff4259e7 ]---
Appears to be benign: no obvious breakage afterwards.
I did not yet bisect -- would you want me to?
Meow!