This bug is missing log files that will aid in diagnosing the problem.
While running an Ubuntu kernel (not a mainline or third-party kernel)
please enter the following command in a terminal window:
apport-collect 1789638
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable
to run this command, please add a comment stating that fact and change
the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the
Ubuntu Kernel Team.
** Changed in: linux (Ubuntu)
Status: New => Incomplete
** Tags added: bionic
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1789638
Title:
azure 4.15 kernel: reading sysfs file causing oops
Status in linux package in Ubuntu:
Incomplete
Bug description:
Kernel: 4.15.0-1021-azure
How to reproduce:
stress-ng --sysfs 0 -t 120
One gets the following:
[ 22.451885] BUG: unable to handle kernel NULL pointer dereference at
0000000000000004
[ 22.455286] IP: read_avail_show+0x1c/0x40
[ 22.455286] PGD 800000042d59e067 P4D 800000042d59e067 PUD 42eb8c067 PMD 0
[ 22.455286] Oops: 0000 [#1] SMP PTI
[ 22.455286] Modules linked in: nf_conntrack_ipv4 nf_defrag_ipv4 xt_owner
xt_conntrack nf_conntrack iptable_security ip_tables x_tables serio_raw joydev
hv_balloon ib_iser iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4
btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq
async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear
hid_generic crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel
aes_x86_64 crypto_simd glue_helper cryptd hyperv_fb hid_hyperv pata_acpi
cfbfillrect hyperv_keyboard cfbimgblt hid cfbcopyarea hv_netvsc hv_utils
[ 22.455286] CPU: 1 PID: 1670 Comm: cat Not tainted 4.15.0-1021-azure
#21~16.04.1-Ubuntu
[ 22.455286] Hardware name: Microsoft Corporation Virtual Machine/Virtual
Machine, BIOS 090007 06/02/2017
[ 22.455286] RIP: 0010:read_avail_show+0x1c/0x40
[ 22.455286] RSP: 0018:ffffafa4c4eafdb0 EFLAGS: 00010286
[ 22.455286] RAX: 0000000000000000 RBX: ffff9db36c93e880 RCX:
ffff9db36f136908
[ 22.860062] RDX: 0000000000000000 RSI: ffff9db364548000 RDI:
ffff9db364548000
[ 22.888042] RBP: ffffafa4c4eafdb0 R08: ffff9db364548000 R09:
ffff9db36c049840
[ 22.920041] R10: ffff9db364548000 R11: 0000000000000000 R12:
ffffffff92ae9440
[ 22.948058] R13: ffff9db36c22d200 R14: 0000000000000001 R15:
ffff9db36c93e880
[ 22.972043] FS: 00007f67eeec6700(0000) GS:ffff9db37fd00000(0000)
knlGS:0000000000000000
[ 23.004046] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 23.024016] CR2: 0000000000000004 CR3: 000000042c37a003 CR4:
00000000001606e0
[ 23.048014] Call Trace:
[ 23.060019] vmbus_chan_attr_show+0x21/0x30
[ 23.076018] sysfs_kf_seq_show+0xa2/0x130
[ 23.088030] kernfs_seq_show+0x27/0x30
[ 23.100020] seq_read+0xb7/0x480
[ 23.112014] kernfs_fop_read+0x111/0x190
[ 23.128017] ? security_file_permission+0xa1/0xc0
[ 23.144013] __vfs_read+0x1b/0x40
[ 23.156019] vfs_read+0x93/0x130
[ 23.168013] SyS_read+0x55/0xc0
[ 23.180021] do_syscall_64+0x73/0x130
[ 23.192014] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[ 23.212022] RIP: 0033:0x7f67ee9d8260
[ 23.224016] RSP: 002b:00007fffdc193ff8 EFLAGS: 00000246 ORIG_RAX:
0000000000000000
[ 23.252022] RAX: ffffffffffffffda RBX: 0000000000020000 RCX:
00007f67ee9d8260
[ 23.276019] RDX: 0000000000020000 RSI: 00007f67eed0c000 RDI:
0000000000000003
[ 23.300020] RBP: 0000000000020000 R08: ffffffffffffffff R09:
0000000000000000
[ 23.328025] R10: 000000000000037b R11: 0000000000000246 R12:
00007f67eed0c000
[ 23.352036] R13: 0000000000000003 R14: 0000000000000000 R15:
0000000000020000
[ 23.376678] Code: fb 3a 17 00 48 98 5d c3 0f 1f 80 00 00 00 00 0f 1f 44 00
00 55 48 8b 87 38 01 00 00 49 89 f0 8b 97 48 01 00 00 4c 89 c7 48 89 e5 <8b> 48
04 8b 00 29 ca 89 c6 29 ce 01 c2 39 c1 0f 46 d6 48 c7 c6
[ 23.444022] RIP: read_avail_show+0x1c/0x40 RSP: ffffafa4c4eafdb0
[ 23.468021] CR2: 0000000000000004
[ 23.481135] ---[ end trace 348a4b7d5a6747d1 ]---
Cornered this down to just reading:
cat
/sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07/VMBUS:01/99221fa0
-24ad-11e2-be98-001aa01bbf6e/channels/4/read_avail
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1789638/+subscriptions
--
Mailing list: https://launchpad.net/~kernel-packages
Post to : [email protected]
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
