[UBUNTU 20.04] zPCI: Enabling of a reserved PCI function regression introduced by multi-function support
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| Ubuntu on IBM z Systems |
Fix Released
|
Undecided
|
Unassigned | ||
| linux (Ubuntu) |
Fix Released
|
Undecided
|
Skipper Bug Screeners | ||
| Focal |
Fix Released
|
Undecided
|
Unassigned | ||
| Groovy |
Fix Released
|
Undecided
|
Skipper Bug Screeners | ||
Bug Description
SRU Justification:
==================
[Impact]
* If a NVMe drive is assigned/hotplugged to a Linux on s390x LPAR, a bug in lib/list_debug.c is hit and the device is not accessible.
* The reason is a missing /dev/ file -- lspci does not report it either.
[Fix]
* 3047766bc6ec9c6
[Test Case]
* Assign a NMVe drive to your LPAR (using the HMC)
* Unassign the NVMe drive from your LPAR
* Reassign it to your LPAR again
* Look at dmesg for 'kernel BUG at lib/list_debug.c'
[Regression Potential]
* There is some regression risk with having code changes in the zPCI sub-system.
* zPCI is the PCI implementation on s390x, modifications here do not affect any other architecture.
* It could be that PCI events do not work anymore and NVMe devices don't IPL (boot) on s390x anymore.
* However, the code changes below to a single file: arch/s390/
* and IPL from NVMe is brand new in Ubuntu for s390x,
* and zPCI devices are less wide-spread compared to ccw devices on s390x.
* On top a test kernel was build and made available for further testing.
[Other]
* Since the fix/patch got upstream accepted with kernel v5.8-rc5, it's already in the groovy proposed kernel 5.8, hence this SRU is for focal only.
__________
When a NVMe drive is assigned/hotplugged to a Linux LPAR then
a bug is hit in lib/list_debug.c. And the device is not accessible, there is no /dev/ file
and lspci does not report it also.
[ 1681.564462] list_add double add: new=00000000eed
[ 1681.564489] ------------[ cut here ]------------
[ 1681.564490] kernel BUG at lib/list_
[ 1681.564504] monitor event: 0040 ilc:2 [#1] SMP
[ 1681.564507] Modules linked in: ip6t_REJECT nf_reject_ipv6 ip6t_rpfilter ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_mangle ip6table_raw ip6table_security iptable_nat nf_nat iptable_mangle iptable_raw iptable_security nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c ip_set nfnetlink ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter s390_trng ghash_s390 prng aes_s390 des_s390 libdes sha512_s390 vfio_ccw sha1_s390 vfio_mdev mdev chsc_sch vfio_iommu_type1 eadm_sch vfio ip_tables dm_service_time nvme crc32_vx_s390 sha256_s390 sha_common nvme_core qeth_l2 zfcp qeth scsi_transport_fc qdio ccwgroup dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua pkey zcrypt
[ 1681.564534] CPU: 6 PID: 139 Comm: kmcheck Not tainted 5.8.0-rc1+ #2
[ 1681.564535] Hardware name: IBM 8561 T01 701 (LPAR)
[ 1681.564536] Krnl PSW : 0704c00180000000 000000003ffcadb8 (__list_
[ 1681.564544] R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
[ 1681.564545] Krnl GPRS: 0000000000000040 0000000000000027 0000000000000058 0000000000000007
[ 1681.564546] 000000003ffcadb4 0000000000000000 0000000000000000 000003e0051a7ce0
[ 1681.564547] 000000004070a300 00000000eed0f808 00000000eed0f808 000000004070a300
[ 1681.564548] 00000000f56a2000 0000000040c2c788 000000003ffcadb4 000003e0051a7bc8
[ 1681.564583] Krnl Code: 000000003ffcada8: c02000302b09 larl %r2,00000000405
[ 1681.564592] Call Trace:
[ 1681.564594] [<000000003ffca
[ 1681.564596] ([<000000003ffc
[ 1681.564599] [<000000003faf2
[ 1681.564601] [<000000003faf7
[ 1681.564605] [<0000000040367
[ 1681.564607] [<000000004036f
[ 1681.564610] [<000000003fb2a
[ 1681.564613] [<00000000403a5
[ 1681.564614] Last Breaking-
[ 1681.564618] [<000000003fb70
[ 1681.564620] ---[ end trace 7ea67c348aa67e14 ]---
uname:
Linux t83lp49.lnxne.boe 5.8.0-rc1+ #2 SMP Thu Jun 18 12:38:02 CEST 2020 s390x s390x s390x GNU/Linux
How to reproduce:
1. Unassign a NVMe drive in HMC from your LPAR
2. Reassign it to your LPAR again
3. dmesg
This issue is fixed by the following upstream commit
that is also CCed to stable so might be coming in over the stable pulls
in parallel:
3047766bc6ec ("s390/pci: fix enabling a reserved PCI function")
CVE References
| tags: | added: architecture-s39064 bugnameltc-186335 severity-medium targetmilestone-inin2004 |
| Changed in ubuntu: | |
| assignee: | nobody → Skipper Bug Screeners (skipper-screen-team) |
| affects: | ubuntu → linux (Ubuntu) |
| Frank Heimes (fheimes) wrote | #1 |
| Changed in linux (Ubuntu Groovy): | |
| status: | New → Fix Committed |
| Changed in ubuntu-z-systems: | |
| status: | New → Triaged |
| Frank Heimes (fheimes) wrote | #2 |
| Changed in linux (Ubuntu Focal): | |
| status: | New → In Progress |
| Changed in ubuntu-z-systems: | |
| status: | Triaged → In Progress |
| description: | updated |
| Frank Heimes (fheimes) wrote | #3 |
| bugproxy (bugproxy) wrote Comment bridged from LTC Bugzilla | #4 |
| Frank Heimes (fheimes) wrote | #5 |
| Changed in linux (Ubuntu Focal): | |
| status: | In Progress → Fix Committed |
| Changed in ubuntu-z-systems: | |
| status: | In Progress → Fix Committed |
| Ubuntu Kernel Bot (ubuntu-kernel-bot) wrote | #6 |
| tags: | added: verification-needed-focal |
| bugproxy (bugproxy) wrote | #7 |
| Frank Heimes (fheimes) wrote | #8 |
| tags: |
added: verification-done-focal removed: verification-needed-focal |
| bugproxy (bugproxy) wrote | #9 |
| Launchpad Janitor (janitor) wrote | #10 |
| Changed in linux (Ubuntu Focal): | |
| status: | Fix Committed → Fix Released |
| Frank Heimes (fheimes) wrote | #11 |
| Changed in linux (Ubuntu Groovy): | |
| status: | Fix Committed → Fix Released |
| Changed in ubuntu-z-systems: | |
| status: | Fix Committed → Fix Released |
| bugproxy (bugproxy) wrote | #12 |
The commit got upstream accepted with v5.8-rc5 and is with that part of groovy's proposed kernel 5.8:
user@box:
Ubuntu-5.8.0-13.14
Ubuntu-5.8.0-14.15
Ubuntu-5.8.0-15.16
Ubuntu-5.8.0-16.17
v5.8
v5.8-rc5
v5.8-rc6
v5.8-rc7
Hence updating status of groovy entry to Fix Committed.