On 17.07.20 09:55, Stéphane Grosjean wrote:
There's a first WARNING kernel message just when the namespace is deleted. The WARNING turns into a BUG (kernel NULL pointer dereference) when removing the interface itself (for example, when the driver module is removed from memory). Note that the issue occurs with all our internal as well as USB CAN interfaces.
Obviously, the problem doesn't appear when you put the interface back in the root namespace before the destruction, or when the interface is a true Ethernet network interface.
Yes. I checked that with an USB Ethernet interface I have at hand here -
and when deleting the test namespace it just emerges in the root
namespace again.
So I wonder what's missing in our configuration for CAN interfaces that
this transition is not performed :-/
Best regards,
Oliver
Context:
$ uname -a
Linux linux-dev 5.4.0-39-generic #43-Ubuntu SMP Fri Jun 19 10:28:31 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
$ dmesg | grep peak_pci
[ 19.028048] peak_pci 0000:0a:00.0: enabling device (0100 -> 0102)
[ 19.034283] peak_pci 0000:0a:00.0: can6 at reg_base=0x00000000136b8b0b cfg_base=0x00000000b826597c irq=27
[ 19.034378] peak_pci 0000:0a:00.0: can7 at reg_base=0x000000006b3de9a0 cfg_base=0x00000000b826597c irq=27
# ip netns add test
# ip link set dev can6 netns test
# ip netns delete test
[ 1755.805241] ------------[ cut here ]------------
[ 1755.805251] WARNING: CPU: 8 PID: 2635 at net/core/dev.c:10039 netdev_exit+0x44/0x50
[ 1755.805252] Modules linked in: vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) md4 nls_utf8 cifs libarc4 fscache libdes cfg80211 nls_iso8859_1 intel_rapl_msr intel_rapl_common x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel peak_usb 8812au(OE) joydev plin(OE) kvm input_leds pcan(OE) eeepc_wmi snd_hda_codec_hdmi snd_hda_codec_realtek nouveau pcmcia snd_hda_codec_generic asus_wmi pcmcia_core crct10dif_pclmul ghash_clmulni_intel peak_pci sja1000 peak_pciefd ledtrig_audio ttm aesni_intel drm_kms_helper snd_hda_intel snd_intel_dspcfg fb_sys_fops syscopyarea sysfillrect sysimgblt can_dev snd_hda_codec snd_hda_core crypto_simd snd_hwdep cryptd snd_pcm glue_helper snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer sparse_keymap intel_cstate intel_rapl_perf snd video mei_me mei soundcore wmi_bmof intel_wmi_thunderbolt mxm_wmi mac_hid sch_fq_codel parport_pc ppdev lp parport drm ip_tables x_tables autofs4 hid_generic usbhid uas usb_storage hid crc32_pclmul igb e1000e
[ 1755.805306] ahci i2c_i801 i2c_algo_bit lpc_ich libahci dca wmi
[ 1755.805315] CPU: 8 PID: 2635 Comm: kworker/u24:0 Tainted: G OE 5.4.0-39-generic #43-Ubuntu
[ 1755.805316] Hardware name: ASUS All Series/X99-E WS, BIOS 4001 05/27/2019
[ 1755.805319] Workqueue: netns cleanup_net
[ 1755.805324] RIP: 0010:netdev_exit+0x44/0x50
[ 1755.805327] Code: 8b bb 30 01 00 00 e8 8b 9d 97 ff 48 81 fb 00 21 be b5 74 13 48 8b 83 90 00 00 00 48 81 c3 90 00 00 00 48 39 c3 75 03 5b 5d c3 <0f> 0b eb f9 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41
[ 1755.805329] RSP: 0018:ffffb12d0169fdc8 EFLAGS: 00010287
[ 1755.805331] RAX: ffff9624c8a70050 RBX: ffff96247642a710 RCX: 000000008010000b
[ 1755.805333] RDX: 000000008010000c RSI: 0000000000000001 RDI: ffff9624cdc06a00
[ 1755.805334] RBP: ffffb12d0169fdd0 R08: 0000000000000000 R09: ffffffffb4d2e300
[ 1755.805335] R10: ffff9624a0d84000 R11: 0000000000000001 R12: ffffb12d0169fe20
[ 1755.805337] R13: ffffffffb5be3f20 R14: ffffffffb5be3f28 R15: ffff962498ea39d8
[ 1755.805339] FS: 0000000000000000(0000) GS:ffff9624cfa00000(0000) knlGS:0000000000000000
[ 1755.805341] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1755.805342] CR2: 000055fbb59cd8e8 CR3: 000000004aa0a006 CR4: 00000000001606e0
[ 1755.805344] Call Trace:
[ 1755.805350] ops_exit_list.isra.0+0x3b/0x70
[ 1755.805353] cleanup_net+0x1f0/0x300
[ 1755.805359] process_one_work+0x1eb/0x3b0
[ 1755.805363] worker_thread+0x4d/0x400
[ 1755.805367] kthread+0x104/0x140
[ 1755.805370] ? process_one_work+0x3b0/0x3b0
[ 1755.805373] ? kthread_park+0x90/0x90
[ 1755.805378] ret_from_fork+0x35/0x40
[ 1755.805382] ---[ end trace 832a75ad96f8105e ]---
[ 1755.805410] ------------[ cut here ]------------
[ 1755.805416] WARNING: CPU: 8 PID: 2635 at fs/proc/proc_sysctl.c:1714 retire_sysctl_set+0x14/0x18
[ 1755.805417] Modules linked in: vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) md4 nls_utf8 cifs libarc4 fscache libdes cfg80211 nls_iso8859_1 intel_rapl_msr intel_rapl_common x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel peak_usb 8812au(OE) joydev plin(OE) kvm input_leds pcan(OE) eeepc_wmi snd_hda_codec_hdmi snd_hda_codec_realtek nouveau pcmcia snd_hda_codec_generic asus_wmi pcmcia_core crct10dif_pclmul ghash_clmulni_intel peak_pci sja1000 peak_pciefd ledtrig_audio ttm aesni_intel drm_kms_helper snd_hda_intel snd_intel_dspcfg fb_sys_fops syscopyarea sysfillrect sysimgblt can_dev snd_hda_codec snd_hda_core crypto_simd snd_hwdep cryptd snd_pcm glue_helper snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer sparse_keymap intel_cstate intel_rapl_perf snd video mei_me mei soundcore wmi_bmof intel_wmi_thunderbolt mxm_wmi mac_hid sch_fq_codel parport_pc ppdev lp parport drm ip_tables x_tables autofs4 hid_generic usbhid uas usb_storage hid crc32_pclmul igb e1000e
[ 1755.805454] ahci i2c_i801 i2c_algo_bit lpc_ich libahci dca wmi
[ 1755.805460] CPU: 8 PID: 2635 Comm: kworker/u24:0 Tainted: G W OE 5.4.0-39-generic #43-Ubuntu
[ 1755.805461] Hardware name: ASUS All Series/X99-E WS, BIOS 4001 05/27/2019
[ 1755.805463] Workqueue: netns cleanup_net
[ 1755.805467] RIP: 0010:retire_sysctl_set+0x14/0x18
[ 1755.805469] Code: 00 00 00 00 49 c7 40 48 00 00 00 00 49 c7 40 50 00 00 00 00 c3 90 0f 1f 44 00 00 55 48 8b 47 58 48 89 e5 48 85 c0 75 02 5d c3 <0f> 0b 5d c3 0f 1f 44 00 00 55 48 89 e5 48 83 ec 60 48 89 4c 24 48
[ 1755.805471] RSP: 0018:ffffb12d0169fdc0 EFLAGS: 00010282
[ 1755.805473] RAX: ffff9624a697ad58 RBX: ffff96247642a680 RCX: 0000000080150009
[ 1755.805475] RDX: ffff96247642a6b0 RSI: ffffffffb5bfeb48 RDI: ffff96247642a730
[ 1755.805476] RBP: ffffb12d0169fdc0 R08: 0000000000000000 R09: ffffffffb4776d00
[ 1755.805477] R10: ffff9624cad0a9c0 R11: 0000000000000001 R12: ffffb12d0169fe20
[ 1755.805479] R13: ffffffffb5bfeb40 R14: ffffffffb5bfeb48 R15: ffff962498ea39d8
[ 1755.805481] FS: 0000000000000000(0000) GS:ffff9624cfa00000(0000) knlGS:0000000000000000
[ 1755.805482] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1755.805483] CR2: 000055fbb59cd8e8 CR3: 000000004aa0a006 CR4: 00000000001606e0
[ 1755.805485] Call Trace:
[ 1755.805490] sysctl_net_exit+0x15/0x20
[ 1755.805493] ops_exit_list.isra.0+0x3b/0x70
[ 1755.805496] cleanup_net+0x1f0/0x300
[ 1755.805500] process_one_work+0x1eb/0x3b0
[ 1755.805503] worker_thread+0x4d/0x400
[ 1755.805507] kthread+0x104/0x140
[ 1755.805510] ? process_one_work+0x3b0/0x3b0
[ 1755.805512] ? kthread_park+0x90/0x90
[ 1755.805517] ret_from_fork+0x35/0x40
[ 1755.805520] ---[ end trace 832a75ad96f8105f ]---
— Stéphane
-----Message d'origine-----
De : linux-can-owner@xxxxxxxxxxxxxxx <linux-can-owner@xxxxxxxxxxxxxxx> De la part de Oliver Hartkopp
Envoyé : jeudi 16 juillet 2020 20:38
À : Philipp Lehmann <leph1016@xxxxxxxxxxxxxxx>; wg@xxxxxxxxxxxxxx; mkl@xxxxxxxxxxxxxx
Cc : linux-can@xxxxxxxxxxxxxxx; christian.sauer.w@xxxxxxxxxxxxxxxx
Objet : Re: [Bug] Kernel Panic on Deletion of the network-namespace containing the SocketCAN interface
Hi Philipp,
thanks for the report and its reproducer!
I assumed the interfaces - at least in the case of 'real' hardware CAN interfaces - to me moved back to the root name space ... well.
I'll take a look at it.
Best regards,
Oliver
On 16.07.20 18:46, Philipp Lehmann wrote:
If a SocketCAN Interface (Tested with a PCAN-USB adapter) is moved into a network-namespace and the network namespace is deleted afterwards, without moving the device out of the namespace prior to the deletion. The device could not be found in any of the network namespaces afterwards, only a reboot of the system fixes this. If the device is instead removed from the USB-Bus without a restart, a kernel panic is the result.
Output of uname -r [Linux cpc4x 5.4.0-40-generic #44-Ubuntu SMP Tue
Jun 23 00:01:04 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux]
The bug could be reproduced with the following steps:
1. Connect the (USB)-SocketCAN device to the host
2. Add a new network namespace [sudo ip netns add test] 3. Move the
CAN-interface to the network name-space [sudo ip link set dev can0
netns test] 4. Delete the namespace [sudo ip netns delete test] 5.
Remove the adapter from the USB-Bus. In most cases this should result
in a kernel panic
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