Kafs 6.16.0-rc3 BUG: kernel NULL pointer dereference

Tue Jul 29 00:08:05 PDT 2025

pe, 2025-07-18 kello 10:29 +0100, David Howells kirjoitti:
> markus.suvanto at gmail.com wrote:
> 
> > FYI... 
> > So far I can't reproduce oops anymore when using 6.16.0-rc[56].
> 
> :-/
> 
> It hasn't been fixed as far as I know.
> 
> And the kernel you were using previously should have included:
> 
> 	4882ba78574e afs: Fix afs_server ref accounting
> 
> so would seem unlikely to be that.
> 
> David

New oops using kernel 6.16.0-rc7. 
Unfortunately this is another computer, where I have not 
apply your debug patch.

-Markus

[635073.718737] AFS: Cache volume key already in use (afs,station.com,20000019)
[635235.235086] DMAR: DRHD: handling fault status reg 2
[635235.235641] DMAR: [DMA Read NO_PASID] Request device [05:00.0] fault addr 0xfef5a000 [fault reason 0x06] PTE Read
access is not set
[635303.745848] AFS: Cache volume key already in use (afs,station.com,20000019)
[635340.279576] DMAR: DRHD: handling fault status reg 102
[635340.280008] DMAR: [DMA Read NO_PASID] Request device [05:00.0] fault addr 0xff0f8000 [fault reason 0x06] PTE Read
access is not set
[635363.764748] AFS: Cache volume key already in use (afs,station.com,20000019)
[635603.781840] AFS: Cache volume key already in use (afs,station.com,20000019)
[635663.798303] AFS: Cache volume key already in use (afs,station.com,20000019)
[635673.800526] AFS: Cache volume key already in use (afs,station.com,20000019)
[635802.401179] DMAR: DRHD: handling fault status reg 202
[635802.401664] DMAR: [DMA Read NO_PASID] Request device [05:00.0] fault addr 0xfb1ad000 [fault reason 0x06] PTE Read
access is not set
[635845.734529] BUG: kernel NULL pointer dereference, address: 0000000000000010
[635845.734988] #PF: supervisor read access in kernel mode
[635845.735415] #PF: error_code(0x0000) - not-present page
[635845.735845] PGD 0 P4D 0 
[635845.736289] Oops: Oops: 0000 [#1] SMP PTI
[635845.736728] CPU: 3 UID: 0 PID: 910144 Comm: kworker/u65:6 Tainted: G          I         6.16.0-rc7 #1 VOLUNTARY 
[635845.737191] Tainted: [I]=FIRMWARE_WORKAROUND
[635845.737649] Hardware name: Hewlett-Packard HP Z600 Workstation/0AE8h, BIOS 786G4 v03.19 03/11/2011
[635845.738129] Workqueue: kafsd afs_process_async_call [kafs]
[635845.738646] RIP: 0010:afs_deliver_cb_init_call_back_state3+0x38/0x1b0 [kafs]
[635845.739183] Code: 4a 3c 01 0f 84 ac 00 00 00 8b 83 48 01 00 00 83 f8 05 0f 85 69 01 00 00 48 8b 83 a0 00 00 00 48 8b
93 b0 00 00 00 48 8d 48 10 <48> 8b 40 10 48 39 02 0f 84 2b 01 00 00 48 c7 c7 d0 9e fc c1 e8 0f
[635845.739749] RSP: 0018:ffffbb34a1083e08 EFLAGS: 00010246
[635845.740311] RAX: 0000000000000000 RBX: ffffa27c734fa600 RCX: 0000000000000010
[635845.740883] RDX: ffffa27bdc7b9410 RSI: ffffa27bcf8143c0 RDI: ffffa27bdc7b9410
[635845.741463] RBP: ffffa27c734fa620 R08: 0000000000000001 R09: 77000000aaffffff
[635845.742050] R10: 0000000000000000 R11: 0000000000000000 R12: ffffa27c734fa600
[635845.742654] R13: ffffa27bc0091800 R14: ffffa27bd25ef845 R15: ffffa27bc7bf00c0
[635845.743257] FS:  0000000000000000(0000) GS:ffffa27ce66ac000(0000) knlGS:0000000000000000
[635845.743871] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[635845.744493] CR2: 0000000000000010 CR3: 0000000172018000 CR4: 00000000000026f0
[635845.745209] Call Trace:
[635845.745848]  <TASK>
[635845.746490]  afs_deliver_to_call+0x54/0x480 [kafs]
[635845.747161]  ? btrfs_work_helper+0xab/0x1d0 [btrfs]
[635845.747908]  afs_process_async_call+0x6e/0x90 [kafs]
[635845.748588]  process_one_work+0x13c/0x220
[635845.749267]  worker_thread+0x2ca/0x400
[635845.749939]  ? __pfx_worker_thread+0x10/0x10
[635845.750614]  kthread+0xd1/0x1b0
[635845.751316]  ? __pfx_kthread+0x10/0x10
[635845.751999]  ? __pfx_kthread+0x10/0x10
[635845.752679]  ret_from_fork+0x71/0xd0
[635845.753367]  ? __pfx_kthread+0x10/0x10
[635845.754053]  ret_from_fork_asm+0x1a/0x30
[635845.754749]  </TASK>
[635845.755441] Modules linked in: tcp_diag inet_diag bluetooth ecdh_generic ecc libaes uinput md5 algif_hash af_alg
ip6table_nat ip6table_filter iptable_nat xt_MASQUERADE nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter
af_packet veth rc_dib0700_rc5 bridge stp llc si2157 si2168 kafs fcrypt pcbc mt2060 rxrpc krb5 dns_resolver netfs cx23885
altera_ci tda18271 altera_stapl m88ds3103 cx2341x tveeprom videobuf2_dvb i2c_mux videobuf2_dma_sg videobuf2_memops
snd_hda_codec_realtek videobuf2_v4l2 dvb_usb_dib0700 snd_hda_codec_generic intel_powerclamp snd_usb_audio
snd_hda_scodec_component snd_hda_codec_hdmi videodev snd_hda_intel dib9000 snd_intel_dspcfg dib7000m snd_ump
snd_hda_codec dib0090 snd_usbmidi_lib kvm_intel dib0070 dib3000mc snd_hwdep joydev snd_hda_core snd_rawmidi
dibx000_common videobuf2_common mousedev dvb_usb kvm snd_seq_device snd_pcm dvb_core irqbypass rc_core snd_timer
intel_cstate cp210x gpio_ich cfg80211 bfq intel_uncore wmi_bmof evdev mc snd acpi_cpufreq pcspkr regmap_i2c input_leds
[635845.755538]  i7core_edac usbserial soundcore rfkill edac_core lpc_ich rtc_cmos tiny_power_button button sch_fq_codel
ip6_tables ip_tables x_tables wireguard curve25519_x86_64 libchacha20poly1305 libcurve25519_generic libpoly1305
poly1305_x86_64 chacha_x86_64 libchacha ip6_udp_tunnel udp_tunnel smsc47b397 fuse coretemp loop tun configfs
crc32c_cryptoapi hid_logitech_hidpp amdgpu hid_logitech_dj drm_suballoc_helper amdxcp i2c_algo_bit drm_client_lib
mfd_core drm_ttm_helper syscopyarea ttm agpgart sysfillrect sysimgblt fb_sys_fops drm_exec gpu_sched video hid_generic
drm_panel_backlight_quirks cec usbkbd usbmouse drm_buddy drm_display_helper usbhid sr_mod sd_mod cdrom drm_kms_helper
drm psmouse serio_raw atkbd ahci nvme_tcp libahci libps2 drm_panel_orientation_quirks uhci_hcd nvme_fabrics nvme_core
vivaldi_fmap libata tg3 fb ehci_pci backlight ehci_hcd sha512_ssse3 ptp font scsi_mod lcd usbcore pps_core hwmon
ledtrig_backlight scsi_common i2c_core usb_common crc16 wmi i8042 floppy serio btrfs blake2b_generic xor raid6_pq
[635845.759765]  zstd_compress nfnetlink dmi_sysfs sha1_generic sha1_ssse3 ipv6 autofs4
[635845.765546] CR2: 0000000000000010
[635845.766526] ---[ end trace 0000000000000000 ]---
[635845.767541] RIP: 0010:afs_deliver_cb_init_call_back_state3+0x38/0x1b0 [kafs]
[635845.768703] Code: 4a 3c 01 0f 84 ac 00 00 00 8b 83 48 01 00 00 83 f8 05 0f 85 69 01 00 00 48 8b 83 a0 00 00 00 48 8b
93 b0 00 00 00 48 8d 48 10 <48> 8b 40 10 48 39 02 0f 84 2b 01 00 00 48 c7 c7 d0 9e fc c1 e8 0f
[635845.769752] RSP: 0018:ffffbb34a1083e08 EFLAGS: 00010246
[635845.770792] RAX: 0000000000000000 RBX: ffffa27c734fa600 RCX: 0000000000000010
[635845.771840] RDX: ffffa27bdc7b9410 RSI: ffffa27bcf8143c0 RDI: ffffa27bdc7b9410
[635845.772896] RBP: ffffa27c734fa620 R08: 0000000000000001 R09: 77000000aaffffff
[635845.773959] R10: 0000000000000000 R11: 0000000000000000 R12: ffffa27c734fa600
[635845.775030] R13: ffffa27bc0091800 R14: ffffa27bd25ef845 R15: ffffa27bc7bf00c0
[635845.776100] FS:  0000000000000000(0000) GS:ffffa27ce66ac000(0000) knlGS:0000000000000000
[635845.777166] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[635845.778218] CR2: 0000000000000010 CR3: 0000000172018000 CR4: 00000000000026f0
[635845.779276] note: kworker/u65:6[910144] exited with irqs disabled
[635903.822994] AFS: Cache volume key already in use (afs,station.com,20000019)
[635963.842581] AFS: Cache volume key already in use (afs,station.com,20000019)
[635973.843146] AFS: Cache volume key already in use (afs,station.com,20000019)
[636138.555107] DMAR: DRHD: handling fault status reg 302
[636138.556290] DMAR: [DMA Read NO_PASID] Request device [05:00.0] fault addr 0xff4ad000 [fault reason 0x06] PTE Read
access is not set
[636203.875015] AFS: Cache volume key already in use (afs,station.com,20000019)
[636263.892009] AFS: Cache volume key already in use (afs,station.com,20000019)
[636273.890404] AFS: Cache volume key already in use (afs,station.com,20000019)
[636326.555846] DMAR: DRHD: handling fault status reg 402
[636326.557020] DMAR: [DMA Read NO_PASID] Request device [05:00.0] fault addr 0xffb02000 [fault reason 0x06] PTE Read
access is not set
[636503.913095] AFS: Cache volume key already in use (afs,station.com,20000019)
[636563.926945] AFS: Cache volume key already in use (afs,station.com,20000019)
[636803.951925] AFS: Cache volume key already in use (afs,station.com,20000019)