Re: 2b5d1c29f6c4 ("drm/nouveau/disp: PIOR DP uses GPIO for HPD, not PMGR AUX interrupts")

Karol Herbst
2023-08-14T13:21:10Z

On Mon, Aug 14, 2023 at 2:56 PM Karol Herbst <kherbst@redhat.com> wrote:
>
> On Mon, Aug 14, 2023 at 2:48 PM 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 PM Takashi Iwai <tiwai@suse.de> wrote:
> > > >
> > > > 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 PM 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 AM 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 PM Borislav Petkov <bp@alien8.de> wrote:
> > > > > > > > > > > >
> > > > > > > > > > > > On Mon, Aug 07, 2023 at 01:49:42PM +0200, Karol Herbst wrote:
> > > > > > > > > > > > > in what way does it stop? Just not progressing? That 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 0x00000000a877d000-0x00000000ac77d000] (64MB)
> > > > > > > > > > > > [ 3.418227] Initialise system trusted keyrings
> > > > > > > > > > > > [ 3.432273] workingset: timestamp_bits=56 max_order=22 bucket_order=0
> > > > > > > > > > > > [ 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' registered
> > > > > > > > > > > > [ 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, using 1920k, total 1920k
> > > > > > > > > > > > [ 3.485969] efifb: mode is 800x600x32, linelength=3200, pages=1
> > > > > > > > > > > > [ 3.491872] efifb: scrolling: redraw
> > > > > > > > > > > > [ 3.495438] efifb: Truecolor: size=8:8:8:8, shift=24:16:8:0
> > > > > > > > > > > > [ 3.502349] Console: switching to colour frame buffer 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, IRQ sharing enabled
> > > > > > > > > > > > [ 3.616224] 00:05: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 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 = 17, base_baud = 115200) is a 16550A
> > > > > > > > > > > > [ 3.642451] Linux agpgart interface v0.103
> > > > > > > > > > > > [ 3.647141] ACPI: bus type drm_connector registered
> > > > > > > > > > > > [ 3.653261] Console: switching to colour dummy device 80x25
> > > > > > > > > > > > [ 3.659092] nouveau 0000:03:00.0: vgaarb: deactivate vga console
> > > > > > > > > > > > [ 3.665174] nouveau 0000:03:00.0: NVIDIA GT218 (0a8c00b1)
> > > > > > > > > > > > [ 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 MiB
> > > > > > > > > > > > [ 3.953755] nouveau 0000:03:00.0: DRM: GART: 1048576 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: 0xffff888100242100, event: 0xffff8881022de1a0, id: 0x0, bits: 0x1, func: 0x0000000000000000
> > > > > > > > > > > > [ 4.033680] nvkm_uevent_add: uevent: 0xffff888100242300, event: 0xffff8881022de1a0, id: 0x0, bits: 0x1, func: 0x0000000000000000
> > > > > > > > > > > > [ 4.045429] nouveau 0000:03:00.0: DRM: MM: using COPY for buffer copies
> > > > > > > > > > > > [ 4.052059] stackdepot: allocating hash table of 1048576 entries via kvcalloc
> > > > > > > > > > > > [ 4.067191] nvkm_uevent_add: uevent: 0xffff888100242800, event: 0xffff888104b3e260, id: 0x0, bits: 0x1, func: 0x0000000000000000
> > > > > > > > > > > > [ 4.078936] nvkm_uevent_add: uevent: 0xffff888100242900, event: 0xffff888104b3e260, id: 0x1, bits: 0x1, func: 0x0000000000000000
> > > > > > > > > > > > [ 4.090514] nvkm_uevent_add: uevent: 0xffff888100242a00, event: 0xffff888102091f28, id: 0x1, bits: 0x3, func: 0xffffffff8177b700
> > > > > > > > > > > > [ 4.102118] tsc: Refined TSC clocksource calibration: 3591.345 MHz
> > > > > > > > > > > > [ 4.108342] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x33c4635c383, max_idle_ns: 440795314831 ns
> > > > > > > > > > > > [ 4.108401] nvkm_uevent_add: uevent: 0xffff8881020b6000, event: 0xffff888102091f28, id: 0xf, bits: 0x3, func: 0xffffffff8177b700
> > > > > > > > > > > > [ 4.129864] clocksource: Switched to clocksource tsc
> > > > > > > > > > > > [ 4.131478] [drm] Initialized nouveau 1.3.1 20120801 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 line
> > > > > > > > > > > `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 kernel:
> > > > > > > > > > https://bugzilla.suse.com/show_bug.cgi?id=1214073
> > > > > > > > > > Confirmed that reverting the patch cured the issue.
> > > > > > > > > >
> > > > > > > > > > FWIW, loading nouveau showed a refcount_t warning just before 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_uevent`
> > > > > > > > > returns -EINVAL with that patch where it didn't before? I wonder if
> > > > > > > > > it's the `if (&outp->head == &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 reporter
> > > > > > > > testing it :)
> > > > > > > >
> > > > > > >
> > > > > > > attached a patch.
> > > > > >
> > > > > > Thanks. Now I'm building a test kernel and asked the reporter for
> > > > > > 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 copies
> > > > [ 228.436682] ==================================================================
> > > > [ 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 modprobe/6174
> > > >
> > > > [ 228.436728] CPU: 0 PID: 6174 Comm: modprobe Not tainted 6.4.9-4.g5b9ad20-default #1 openSUSE Tumbleweed (unreleased) d0a6841e538b38d17513f6942fb58770372b54fd
> > > > [ 228.436740] Hardware name: Apple Inc. MacBook5,1/Mac-F42D89C8, BIOS 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 d0287dfba9984367c331e8149297392f67038244]
> > > > [ 228.437540] ? drm_encoder_init+0xbe/0x140
> > > > [ 228.437554] ? __pfx_nouveau_connector_create+0x10/0x10 [nouveau d0287dfba9984367c331e8149297392f67038244]
> > > > [ 228.438137] ? nvif_outp_ctor+0x2d9/0x430 [nouveau d0287dfba9984367c331e8149297392f67038244]
> > > > [ 228.438236] nv50_display_create+0xe54/0x30d0 [nouveau d0287dfba9984367c331e8149297392f67038244]
> > > > [ 228.438236] nouveau_display_create+0x903/0x10c0 [nouveau d0287dfba9984367c331e8149297392f67038244]
> > > > [ 228.438236] nouveau_drm_device_init+0x3a4/0x19e0 [nouveau d0287dfba9984367c331e8149297392f67038244]
> > > > [ 228.438236] ? __pfx_nouveau_drm_device_init+0x10/0x10 [nouveau d0287dfba9984367c331e8149297392f67038244]
> > > > [ 228.438236] ? __pfx_pci_update_current_state+0x10/0x10
> > > > [ 228.438236] ? __kasan_check_byte+0x13/0x50
> > > > [ 228.438236] nouveau_drm_probe+0x1a2/0x6b0 [nouveau d0287dfba9984367c331e8149297392f67038244]
> > > > [ 228.438236] ? __pfx__raw_spin_lock_irqsave+0x10/0x10
> > > > [ 228.438236] ? __pfx_nouveau_drm_probe+0x10/0x10 [nouveau d0287dfba9984367c331e8149297392f67038244]
> > > > [ 228.438236] ? __pfx_nouveau_drm_probe+0x10/0x10 [nouveau d0287dfba9984367c331e8149297392f67038244]
> > > > [ 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 d0287dfba9984367c331e8149297392f67038244]
> > > > [ 228.438236] ? __pfx_nouveau_drm_init+0x10/0x10 [nouveau d0287dfba9984367c331e8149297392f67038244]
> > > > [ 228.438236] driver_register+0x134/0x460
> > > > [ 228.438236] ? __pfx_nouveau_drm_init+0x10/0x10 [nouveau d0287dfba9984367c331e8149297392f67038244]
> > > > [ 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: 00007f91ce119a5e
> > > > [ 228.438236] RDX: 00005588462e39c0 RSI: 0000000000fda8b2 RDI: 00007f91cc371010
> > > > [ 228.438236] RBP: 00005588462e39c0 R08: 00005588462e3ce0 R09: 0000000000000000
> > > > [ 228.438236] R10: 000000000005af11 R11: 0000000000000246 R12: 0000000000040000
> > > > [ 228.438236] R13: 0000000000000000 R14: 0000000000000009 R15: 00005588462de7c0
> > > > [ 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 ffff8881731ce000
> > > > 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, ffff8881731cf000)
> > > >
> > > > [ 228.438236] The buggy address belongs to the physical page:
> > > > [ 228.438236] page:00000000d1c274b4 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1731c8
> > > > [ 228.438236] head:00000000d1c274b4 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
> > > > [ 228.438236] flags: 0x17ffffc0010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff)
> > > > [ 228.438236] page_type: 0xffffffff()
> > > > [ 228.438236] raw: 0017ffffc0010200 ffff888100042140 dead000000000122 0000000000000000
> > > > [ 228.438236] raw: 0000000000000000 0000000080040004 00000001ffffffff 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] ==================================================================
> > > >
> > >
> > > 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.
> >

also, you don't need to run it on the same machine if it's all
distribution packaged. As long as you have the exact same binary
available you can resolve the lines. Or just use gdb:
https://docs.kernel.org/admin-guide/bug-hunting.html#gdb

> > 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
> >