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From:   Karol Herbst <kherbst@redhat.com>
Date:   Mon, 14 Aug 2023 14:56:46 +0200
Message-ID: <CACO55tvPGx7npsXg+tpDoz=KXQBs4Pwz3h9Bie-vHithcHV5eA@mail.gmail.com>
Subject: Re: 2b5d1c29f6c4 ("drm/nouveau/disp: PIOR DP uses GPIO for HPD, not
 PMGR AUX interrupts")
To:     Takashi Iwai <tiwai@suse.de>
Cc:     nouveau@lists.freedesktop.org, lkml <linux-kernel@vger.kernel.org>,
        dri-devel@lists.freedesktop.org, regressions@leemhuis.info,
        Borislav Petkov <bp@alien8.de>, Ben Skeggs <bskeggs@redhat.com>
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On Mon, Aug 14, 2023 at 2:48=E2=80=AFPM Takashi Iwai <tiwai@suse.de> wrote:
>
> On Mon, 14 Aug 2023 14:38:18 +0200,
> Karol Herbst wrote:
> >
> > On Wed, Aug 9, 2023 at 6:16=E2=80=AFPM Takashi Iwai <tiwai@suse.de> wro=
te:
> > >
> > > On Wed, 09 Aug 2023 16:46:38 +0200,
> > > Takashi Iwai wrote:
> > > >
> > > > On Wed, 09 Aug 2023 15:13:23 +0200,
> > > > Takashi Iwai wrote:
> > > > >
> > > > > On Wed, 09 Aug 2023 14:19:23 +0200,
> > > > > Karol Herbst wrote:
> > > > > >
> > > > > > On Wed, Aug 9, 2023 at 1:46=E2=80=AFPM Takashi Iwai <tiwai@suse=
.de> wrote:
> > > > > > >
> > > > > > > On Wed, 09 Aug 2023 13:42:09 +0200,
> > > > > > > Karol Herbst wrote:
> > > > > > > >
> > > > > > > > On Wed, Aug 9, 2023 at 11:22=E2=80=AFAM Takashi Iwai <tiwai=
@suse.de> wrote:
> > > > > > > > >
> > > > > > > > > On Tue, 08 Aug 2023 12:39:32 +0200,
> > > > > > > > > Karol Herbst wrote:
> > > > > > > > > >
> > > > > > > > > > On Mon, Aug 7, 2023 at 5:05=E2=80=AFPM Borislav Petkov =
<bp@alien8.de> wrote:
> > > > > > > > > > >
> > > > > > > > > > > On Mon, Aug 07, 2023 at 01:49:42PM +0200, Karol Herbs=
t wrote:
> > > > > > > > > > > > in what way does it stop? Just not progressing? Tha=
t would be kinda
> > > > > > > > > > > > concerning. Mind tracing with what arguments `nvkm_=
uevent_add` is
> > > > > > > > > > > > called with and without that patch?
> > > > > > > > > > >
> > > > > > > > > > > Well, me dumping those args I guess made the box not =
freeze before
> > > > > > > > > > > catching a #PF over serial. Does that help?
> > > > > > > > > > >
> > > > > > > > > > > ....
> > > > > > > > > > > [    3.410135] Unpacking initramfs...
> > > > > > > > > > > [    3.416319] software IO TLB: mapped [mem 0x0000000=
0a877d000-0x00000000ac77d000] (64MB)
> > > > > > > > > > > [    3.418227] Initialise system trusted keyrings
> > > > > > > > > > > [    3.432273] workingset: timestamp_bits=3D56 max_or=
der=3D22 bucket_order=3D0
> > > > > > > > > > > [    3.439006] ntfs: driver 2.1.32 [Flags: R/W].
> > > > > > > > > > > [    3.443368] fuse: init (API version 7.38)
> > > > > > > > > > > [    3.447601] 9p: Installing v9fs 9p2000 file system=
 support
> > > > > > > > > > > [    3.453223] Key type asymmetric registered
> > > > > > > > > > > [    3.457332] Asymmetric key parser 'x509' registere=
d
> > > > > > > > > > > [    3.462236] Block layer SCSI generic (bsg) driver =
version 0.4 loaded (major 250)
> > > > > > > > > > > [    3.475865] efifb: probing for efifb
> > > > > > > > > > > [    3.479458] efifb: framebuffer at 0xf9000000, usin=
g 1920k, total 1920k
> > > > > > > > > > > [    3.485969] efifb: mode is 800x600x32, linelength=
=3D3200, pages=3D1
> > > > > > > > > > > [    3.491872] efifb: scrolling: redraw
> > > > > > > > > > > [    3.495438] efifb: Truecolor: size=3D8:8:8:8, shif=
t=3D24:16:8:0
> > > > > > > > > > > [    3.502349] Console: switching to colour frame buf=
fer device 100x37
> > > > > > > > > > > [    3.509564] fb0: EFI VGA frame buffer device
> > > > > > > > > > > [    3.514013] ACPI: \_PR_.CP00: Found 4 idle states
> > > > > > > > > > > [    3.518850] ACPI: \_PR_.CP01: Found 4 idle states
> > > > > > > > > > > [    3.523687] ACPI: \_PR_.CP02: Found 4 idle states
> > > > > > > > > > > [    3.528515] ACPI: \_PR_.CP03: Found 4 idle states
> > > > > > > > > > > [    3.533346] ACPI: \_PR_.CP04: Found 4 idle states
> > > > > > > > > > > [    3.538173] ACPI: \_PR_.CP05: Found 4 idle states
> > > > > > > > > > > [    3.543003] ACPI: \_PR_.CP06: Found 4 idle states
> > > > > > > > > > > [    3.544219] Freeing initrd memory: 8196K
> > > > > > > > > > > [    3.547844] ACPI: \_PR_.CP07: Found 4 idle states
> > > > > > > > > > > [    3.609542] Serial: 8250/16550 driver, 4 ports, IR=
Q sharing enabled
> > > > > > > > > > > [    3.616224] 00:05: ttyS0 at I/O 0x3f8 (irq =3D 4, =
base_baud =3D 115200) is a 16550A
> > > > > > > > > > > [    3.625552] serial 0000:00:16.3: enabling device (=
0000 -> 0003)
> > > > > > > > > > > [    3.633034] 0000:00:16.3: ttyS1 at I/O 0xf0a0 (irq=
 =3D 17, base_baud =3D 115200) is a 16550A
> > > > > > > > > > > [    3.642451] Linux agpgart interface v0.103
> > > > > > > > > > > [    3.647141] ACPI: bus type drm_connector registere=
d
> > > > > > > > > > > [    3.653261] Console: switching to colour dummy dev=
ice 80x25
> > > > > > > > > > > [    3.659092] nouveau 0000:03:00.0: vgaarb: deactiva=
te vga console
> > > > > > > > > > > [    3.665174] nouveau 0000:03:00.0: NVIDIA GT218 (0a=
8c00b1)
> > > > > > > > > > > [    3.784585] nouveau 0000:03:00.0: bios: version 70=
.18.83.00.08
> > > > > > > > > > > [    3.792244] nouveau 0000:03:00.0: fb: 512 MiB DDR3
> > > > > > > > > > > [    3.948786] nouveau 0000:03:00.0: DRM: VRAM: 512 M=
iB
> > > > > > > > > > > [    3.953755] nouveau 0000:03:00.0: DRM: GART: 10485=
76 MiB
> > > > > > > > > > > [    3.959073] nouveau 0000:03:00.0: DRM: TMDS table =
version 2.0
> > > > > > > > > > > [    3.964808] nouveau 0000:03:00.0: DRM: DCB version=
 4.0
> > > > > > > > > > > [    3.969938] nouveau 0000:03:00.0: DRM: DCB outp 00=
: 02000360 00000000
> > > > > > > > > > > [    3.976367] nouveau 0000:03:00.0: DRM: DCB outp 01=
: 02000362 00020010
> > > > > > > > > > > [    3.982792] nouveau 0000:03:00.0: DRM: DCB outp 02=
: 028003a6 0f220010
> > > > > > > > > > > [    3.989223] nouveau 0000:03:00.0: DRM: DCB outp 03=
: 01011380 00000000
> > > > > > > > > > > [    3.995647] nouveau 0000:03:00.0: DRM: DCB outp 04=
: 08011382 00020010
> > > > > > > > > > > [    4.002076] nouveau 0000:03:00.0: DRM: DCB outp 05=
: 088113c6 0f220010
> > > > > > > > > > > [    4.008511] nouveau 0000:03:00.0: DRM: DCB conn 00=
: 00101064
> > > > > > > > > > > [    4.014151] nouveau 0000:03:00.0: DRM: DCB conn 01=
: 00202165
> > > > > > > > > > > [    4.021710] nvkm_uevent_add: uevent: 0xffff8881002=
42100, event: 0xffff8881022de1a0, id: 0x0, bits: 0x1, func: 0x0000000000000=
000
> > > > > > > > > > > [    4.033680] nvkm_uevent_add: uevent: 0xffff8881002=
42300, event: 0xffff8881022de1a0, id: 0x0, bits: 0x1, func: 0x0000000000000=
000
> > > > > > > > > > > [    4.045429] nouveau 0000:03:00.0: DRM: MM: using C=
OPY for buffer copies
> > > > > > > > > > > [    4.052059] stackdepot: allocating hash table of 1=
048576 entries via kvcalloc
> > > > > > > > > > > [    4.067191] nvkm_uevent_add: uevent: 0xffff8881002=
42800, event: 0xffff888104b3e260, id: 0x0, bits: 0x1, func: 0x0000000000000=
000
> > > > > > > > > > > [    4.078936] nvkm_uevent_add: uevent: 0xffff8881002=
42900, event: 0xffff888104b3e260, id: 0x1, bits: 0x1, func: 0x0000000000000=
000
> > > > > > > > > > > [    4.090514] nvkm_uevent_add: uevent: 0xffff8881002=
42a00, event: 0xffff888102091f28, id: 0x1, bits: 0x3, func: 0xffffffff8177b=
700
> > > > > > > > > > > [    4.102118] tsc: Refined TSC clocksource calibrati=
on: 3591.345 MHz
> > > > > > > > > > > [    4.108342] clocksource: tsc: mask: 0xffffffffffff=
ffff max_cycles: 0x33c4635c383, max_idle_ns: 440795314831 ns
> > > > > > > > > > > [    4.108401] nvkm_uevent_add: uevent: 0xffff8881020=
b6000, event: 0xffff888102091f28, id: 0xf, bits: 0x3, func: 0xffffffff8177b=
700
> > > > > > > > > > > [    4.129864] clocksource: Switched to clocksource t=
sc
> > > > > > > > > > > [    4.131478] [drm] Initialized nouveau 1.3.1 201208=
01 for 0000:03:00.0 on minor 0
> > > > > > > > > > > [    4.143806] BUG: kernel NULL pointer dereference, =
address: 0000000000000020
> > > > > > > > > >
> > > > > > > > > > ahh, that would have been good to know :) Mind figuring=
 out what's
> > > > > > > > > > exactly NULL inside nvif_object_mthd? Or rather what li=
ne
> > > > > > > > > > `nvif_object_mthd+0x136` belongs to, then it should be =
easy to figure
> > > > > > > > > > out what's wrong here.
> > > > > > > > >
> > > > > > > > > FWIW, we've hit the bug on openSUSE Tumbleweed 6.4.8 kern=
el:
> > > > > > > > >   https://bugzilla.suse.com/show_bug.cgi?id=3D1214073
> > > > > > > > > Confirmed that reverting the patch cured the issue.
> > > > > > > > >
> > > > > > > > > FWIW, loading nouveau showed a refcount_t warning just be=
fore the NULL
> > > > > > > > > dereference:
> > > > > > > > >
> > > > > > > >
> > > > > > > > mh, I wonder if one of those `return -EINVAL;` branches is =
hit where
> > > > > > > > it wasn't before. Could some of you check if `nvkm_uconn_ue=
vent`
> > > > > > > > returns -EINVAL with that patch where it didn't before? I w=
onder if
> > > > > > > > it's the `if (&outp->head =3D=3D &conn->disp->outps) return=
 -EINVAL;` and
> > > > > > > > if remove that fixes the crash?
> > > > > > >
> > > > > > > Please give a patch, then I can build a kernel and let the re=
porter
> > > > > > > testing it :)
> > > > > > >
> > > > > >
> > > > > > attached a patch.
> > > > >
> > > > > Thanks.  Now I'm building a test kernel and asked the reporter fo=
r
> > > > > testing it.
> > > >
> > > > And the result was negative, the boot still hanged up.
> > >
> > > And below is another log from the 6.4.8 kernel with KASAN-enabled.
> > > Some memory corruption seems happening.
> > >
> > > [  228.422919] nouveau 0000:02:00.0: DRM: DCB conn 01: 0000a146
> > > [  228.428674] nouveau 0000:02:00.0: DRM: MM: using M2MF for buffer c=
opies
> > > [  228.436682] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> > > [  228.436698] BUG: KASAN: slab-use-after-free in drm_connector_list_=
iter_next+0x176/0x320
> > > [  228.436715] Read of size 4 at addr ffff8881731ce050 by task modpro=
be/6174
> > >
> > > [  228.436728] CPU: 0 PID: 6174 Comm: modprobe Not tainted 6.4.9-4.g5=
b9ad20-default #1 openSUSE Tumbleweed (unreleased) d0a6841e538b38d17513f694=
2fb58770372b54fd
> > > [  228.436740] Hardware name: Apple Inc. MacBook5,1/Mac-F42D89C8, BIO=
S     MB51.88Z.007D.B03.0904271443 04/27/09
> > > [  228.436747] Call Trace:
> > > [  228.436753]  <TASK>
> > > [  228.436759]  dump_stack_lvl+0x47/0x60
> > > [  228.436773]  print_report+0xcf/0x640
> > > [  228.436784]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
> > > [  228.436797]  ? drm_connector_list_iter_next+0x176/0x320
> > > [  228.436807]  kasan_report+0xb1/0xe0
> > > [  228.436817]  ? drm_connector_list_iter_next+0x176/0x320
> > > [  228.436828]  kasan_check_range+0x105/0x1b0
> > > [  228.436837]  drm_connector_list_iter_next+0x176/0x320
> > > [  228.436848]  ? __pfx_drm_connector_list_iter_next+0x10/0x10
> > > [  228.436859]  ? __kmem_cache_free+0x18a/0x2c0
> > > [  228.436868]  nouveau_connector_create+0x170/0x1cd0 [nouveau d0287d=
fba9984367c331e8149297392f67038244]
> > > [  228.437540]  ? drm_encoder_init+0xbe/0x140
> > > [  228.437554]  ? __pfx_nouveau_connector_create+0x10/0x10 [nouveau d=
0287dfba9984367c331e8149297392f67038244]
> > > [  228.438137]  ? nvif_outp_ctor+0x2d9/0x430 [nouveau d0287dfba998436=
7c331e8149297392f67038244]
> > > [  228.438236]  nv50_display_create+0xe54/0x30d0 [nouveau d0287dfba99=
84367c331e8149297392f67038244]
> > > [  228.438236]  nouveau_display_create+0x903/0x10c0 [nouveau d0287dfb=
a9984367c331e8149297392f67038244]
> > > [  228.438236]  nouveau_drm_device_init+0x3a4/0x19e0 [nouveau d0287df=
ba9984367c331e8149297392f67038244]
> > > [  228.438236]  ? __pfx_nouveau_drm_device_init+0x10/0x10 [nouveau d0=
287dfba9984367c331e8149297392f67038244]
> > > [  228.438236]  ? __pfx_pci_update_current_state+0x10/0x10
> > > [  228.438236]  ? __kasan_check_byte+0x13/0x50
> > > [  228.438236]  nouveau_drm_probe+0x1a2/0x6b0 [nouveau d0287dfba99843=
67c331e8149297392f67038244]
> > > [  228.438236]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
> > > [  228.438236]  ? __pfx_nouveau_drm_probe+0x10/0x10 [nouveau d0287dfb=
a9984367c331e8149297392f67038244]
> > > [  228.438236]  ? __pfx_nouveau_drm_probe+0x10/0x10 [nouveau d0287dfb=
a9984367c331e8149297392f67038244]
> > > [  228.438236]  local_pci_probe+0xdd/0x190
> > > [  228.438236]  pci_device_probe+0x23a/0x770
> > > [  228.438236]  ? kernfs_add_one+0x2d8/0x450
> > > [  228.438236]  ? kernfs_get.part.0+0x4c/0x70
> > > [  228.438236]  ? __pfx_pci_device_probe+0x10/0x10
> > > [  228.438236]  ? kernfs_create_link+0x15f/0x230
> > > [  228.438236]  ? kernfs_put+0x1c/0x40
> > > [  228.438236]  ? sysfs_do_create_link_sd+0x8e/0x100
> > > [  228.438236]  really_probe+0x3e2/0xb80
> > > [  228.438236]  __driver_probe_device+0x18c/0x450
> > > [  228.438236]  ? __pfx_klist_iter_init_node+0x10/0x10
> > > [  228.438236]  driver_probe_device+0x4a/0x120
> > > [  228.438236]  __driver_attach+0x1e1/0x4a0
> > > [  228.438236]  ? __pfx___driver_attach+0x10/0x10
> > > [  228.438236]  bus_for_each_dev+0xf4/0x170
> > > [  228.438236]  ? __pfx__raw_spin_lock+0x10/0x10
> > > [  228.438236]  ? __pfx_bus_for_each_dev+0x10/0x10
> > > [  228.438236]  bus_add_driver+0x29e/0x570
> > > [  228.438236]  ? __pfx_nouveau_drm_init+0x10/0x10 [nouveau d0287dfba=
9984367c331e8149297392f67038244]
> > > [  228.438236]  ? __pfx_nouveau_drm_init+0x10/0x10 [nouveau d0287dfba=
9984367c331e8149297392f67038244]
> > > [  228.438236]  driver_register+0x134/0x460
> > > [  228.438236]  ? __pfx_nouveau_drm_init+0x10/0x10 [nouveau d0287dfba=
9984367c331e8149297392f67038244]
> > > [  228.438236]  do_one_initcall+0x8e/0x310
> > > [  228.438236]  ? __pfx_do_one_initcall+0x10/0x10
> > > [  228.438236]  ? __kmem_cache_alloc_node+0x1b9/0x3b0
> > > [  228.438236]  ? do_init_module+0x4b/0x730
> > > [  228.438236]  ? kasan_unpoison+0x44/0x70
> > > [  228.438236]  do_init_module+0x238/0x730
> > > [  228.438236]  load_module+0x5b41/0x6dd0
> > > [  228.438236]  ? __pfx_load_module+0x10/0x10
> > > [  228.438236]  ? _raw_spin_lock+0x85/0xe0
> > > [  228.438236]  ? __pfx__raw_spin_lock+0x10/0x10
> > > [  228.438236]  ? find_vmap_area+0xab/0xe0
> > > [  228.438236]  ? __do_sys_init_module+0x1df/0x210
> > > [  228.438236]  __do_sys_init_module+0x1df/0x210
> > > [  228.438236]  ? __pfx___do_sys_init_module+0x10/0x10
> > > [  228.438236]  ? syscall_exit_to_user_mode+0x1b/0x40
> > > [  228.438236]  ? do_syscall_64+0x6c/0x90
> > > [  228.438236]  ? __pfx_ksys_read+0x10/0x10
> > > [  228.438236]  do_syscall_64+0x60/0x90
> > > [  228.438236]  ? syscall_exit_to_user_mode+0x1b/0x40
> > > [  228.438236]  ? do_syscall_64+0x6c/0x90
> > > [  228.438236]  ? syscall_exit_to_user_mode+0x1b/0x40
> > > [  228.438236]  ? do_syscall_64+0x6c/0x90
> > > [  228.438236]  ? exc_page_fault+0x62/0xd0
> > > [  228.438236]  entry_SYSCALL_64_after_hwframe+0x77/0xe1
> > > [  228.438236] RIP: 0033:0x7f91ce119a5e
> > > [  228.438236] Code: c3 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 =
90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 49 89 ca b8 af 00 00 00 0f =
05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 7a 03 0d 00 f7 d8 64 89 01 48
> > > [  228.438236] RSP: 002b:00007ffce2813538 EFLAGS: 00000246 ORIG_RAX: =
00000000000000af
> > > [  228.438236] RAX: ffffffffffffffda RBX: 00005588462def10 RCX: 00007=
f91ce119a5e
> > > [  228.438236] RDX: 00005588462e39c0 RSI: 0000000000fda8b2 RDI: 00007=
f91cc371010
> > > [  228.438236] RBP: 00005588462e39c0 R08: 00005588462e3ce0 R09: 00000=
00000000000
> > > [  228.438236] R10: 000000000005af11 R11: 0000000000000246 R12: 00000=
00000040000
> > > [  228.438236] R13: 0000000000000000 R14: 0000000000000009 R15: 00005=
588462de7c0
> > > [  228.438236]  </TASK>
> > >
> > > [  228.438236] Allocated by task 6174:
> > > [  228.438236]  kasan_save_stack+0x20/0x40
> > > [  228.438236]  kasan_set_track+0x25/0x30
> > > [  228.438236]  __kasan_kmalloc+0xaa/0xb0
> > > [  228.438236]  nouveau_connector_create+0x386/0x1cd0 [nouveau]
> > > [  228.438236]  nv50_display_create+0xe54/0x30d0 [nouveau]
> > > [  228.438236]  nouveau_display_create+0x903/0x10c0 [nouveau]
> > > [  228.438236]  nouveau_drm_device_init+0x3a4/0x19e0 [nouveau]
> > > [  228.438236]  nouveau_drm_probe+0x1a2/0x6b0 [nouveau]
> > > [  228.438236]  local_pci_probe+0xdd/0x190
> > > [  228.438236]  pci_device_probe+0x23a/0x770
> > > [  228.438236]  really_probe+0x3e2/0xb80
> > > [  228.438236]  __driver_probe_device+0x18c/0x450
> > > [  228.438236]  driver_probe_device+0x4a/0x120
> > > [  228.438236]  __driver_attach+0x1e1/0x4a0
> > > [  228.438236]  bus_for_each_dev+0xf4/0x170
> > > [  228.438236]  bus_add_driver+0x29e/0x570
> > > [  228.438236]  driver_register+0x134/0x460
> > > [  228.438236]  do_one_initcall+0x8e/0x310
> > > [  228.438236]  do_init_module+0x238/0x730
> > > [  228.438236]  load_module+0x5b41/0x6dd0
> > > [  228.438236]  __do_sys_init_module+0x1df/0x210
> > > [  228.438236]  do_syscall_64+0x60/0x90
> > > [  228.438236]  entry_SYSCALL_64_after_hwframe+0x77/0xe1
> > >
> > > [  228.438236] Freed by task 6174:
> > > [  228.438236]  kasan_save_stack+0x20/0x40
> > > [  228.438236]  kasan_set_track+0x25/0x30
> > > [  228.438236]  kasan_save_free_info+0x2e/0x50
> > > [  228.438236]  ____kasan_slab_free+0x169/0x1c0
> > > [  228.438236]  slab_free_freelist_hook+0xcd/0x190
> > > [  228.438236]  __kmem_cache_free+0x18a/0x2c0
> > > [  228.438236]  nouveau_connector_create+0x1423/0x1cd0 [nouveau]
> > > [  228.438236]  nv50_display_create+0xe54/0x30d0 [nouveau]
> > > [  228.438236]  nouveau_display_create+0x903/0x10c0 [nouveau]
> > > [  228.438236]  nouveau_drm_device_init+0x3a4/0x19e0 [nouveau]
> > > [  228.438236]  nouveau_drm_probe+0x1a2/0x6b0 [nouveau]
> > > [  228.438236]  local_pci_probe+0xdd/0x190
> > > [  228.438236]  pci_device_probe+0x23a/0x770
> > > [  228.438236]  really_probe+0x3e2/0xb80
> > > [  228.438236]  __driver_probe_device+0x18c/0x450
> > > [  228.438236]  driver_probe_device+0x4a/0x120
> > > [  228.438236]  __driver_attach+0x1e1/0x4a0
> > > [  228.438236]  bus_for_each_dev+0xf4/0x170
> > > [  228.438236]  bus_add_driver+0x29e/0x570
> > > [  228.438236]  driver_register+0x134/0x460
> > > [  228.438236]  do_one_initcall+0x8e/0x310
> > > [  228.438236]  do_init_module+0x238/0x730
> > > [  228.438236]  load_module+0x5b41/0x6dd0
> > > [  228.438236]  __do_sys_init_module+0x1df/0x210
> > > [  228.438236]  do_syscall_64+0x60/0x90
> > > [  228.438236]  entry_SYSCALL_64_after_hwframe+0x77/0xe1
> > >
> > > [  228.438236] The buggy address belongs to the object at ffff8881731=
ce000
> > >                 which belongs to the cache kmalloc-4k of size 4096
> > > [  228.438236] The buggy address is located 80 bytes inside of
> > >                 freed 4096-byte region [ffff8881731ce000, ffff8881731=
cf000)
> > >
> > > [  228.438236] The buggy address belongs to the physical page:
> > > [  228.438236] page:00000000d1c274b4 refcount:1 mapcount:0 mapping:00=
00000000000000 index:0x0 pfn:0x1731c8
> > > [  228.438236] head:00000000d1c274b4 order:3 entire_mapcount:0 nr_pag=
es_mapped:0 pincount:0
> > > [  228.438236] flags: 0x17ffffc0010200(slab|head|node=3D0|zone=3D2|la=
stcpupid=3D0x1fffff)
> > > [  228.438236] page_type: 0xffffffff()
> > > [  228.438236] raw: 0017ffffc0010200 ffff888100042140 dead00000000012=
2 0000000000000000
> > > [  228.438236] raw: 0000000000000000 0000000080040004 00000001fffffff=
f 0000000000000000
> > > [  228.438236] page dumped because: kasan: bad access detected
> > >
> > > [  228.438236] Memory state around the buggy address:
> > > [  228.438236]  ffff8881731cdf00: fc fc fc fc fc fc fc fc fc fc fc fc=
 fc fc fc fc
> > > [  228.438236]  ffff8881731cdf80: fc fc fc fc fc fc fc fc fc fc fc fc=
 fc fc fc fc
> > > [  228.438236] >ffff8881731ce000: fa fb fb fb fb fb fb fb fb fb fb fb=
 fb fb fb fb
> > > [  228.438236]                                                  ^
> > > [  228.438236]  ffff8881731ce080: fb fb fb fb fb fb fb fb fb fb fb fb=
 fb fb fb fb
> > > [  228.438236]  ffff8881731ce100: fb fb fb fb fb fb fb fb fb fb fb fb=
 fb fb fb fb
> > > [  228.438236] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> > >
> >
> > mind resolving those to file lines via decode_stacktrace.sh or
> > something, because looking at it, it makes no sense really.
>
> I don't own the machine, so it's a bit difficult from my side,
> unfortunately.
>
> But you can read the log and find easily that the object is *freed*
> at nouveau_connector_create() called from nv50_display_create().  It
> implies that, even after a connector is freed by an error, yet the
> object is still referred at nouveau_display_create().  This explains
> why the error starts appearing after you put an extra check to return
> -EINVAL.
>

yeah, but looking at the code it makes no sense. That's why I want to
be sure it's the allocation I think it is, because it might be as well
a different one I don't really see atm.

> That said, my bet is that some incorrect error handling and the
> resource releases at the connector creation.
>
>
> thanks,
>
> Takashi
>