s390x kernel oops shrinking memory pages on a KVM guest. A possible process data corruption caused by a known bug on the KVM host.

Solution Unverified - Updated -


  • x390x kernel oops shrinking memory pages on a KVM guest.
[23023.010420] Unable to handle kernel pointer dereference at virtual kernel address a302676eb3c41000
[23023.010521] Oops: 0038 [#1] SMP 
[23023.010526] Modules linked in: ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat iptable_mangle iptable_security iptable_raw nf_conntrack ip_set nfnetlink ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc ext4 mbcache jbd2 sg binfmt_misc ip_tables xfs libcrc32c sr_mod cdrom virtio_net net_failover failover virtio_scsi virtio_blk dm_mirror dm_region_hash dm_log dm_mod pkey zcrypt ap sha512_s390 ghash_s390 des_s390 des_generic aes_s390 prng
[23023.010570] CPU: 3 PID: 90 Comm: kswapd0 Kdump: loaded Not tainted 3.10.0-1160.el7.s390x #1
[23023.010574] task: 00000053203d2f00 ti: 000000531b134000 task.ti: 000000531b134000
[23023.010576] Krnl PSW : 0404d00180000000 000000000048b10c (radix_tree_descend+0x4/0x68)
[23023.010585]            R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 EA:3
               Krnl GPRS: 00000000002ffbf8 a302676eb3c41491 a302676eb3c41490 000000531b1378b8
[23023.010590]            0000000002687600 a302676eb3c41490 0000005300000001 000003d100000000
[23023.010591]            000000531b137908 000000531b137910 0000000000000040 000000531f9c8e10
[23023.010593]            0000000002687600 a302676eb3c41490 000000000048cb42 000000531b137818
[23023.010608] Krnl Code: 000000000048b104: 0707        bcr 0,%r7
                   000000000048b106: 0707       bcr 0,%r7
                  #000000000048b108: b9040052       lgr %r5,%r2
                  >000000000048b10c: e32020000094   llc %r2,0(%r2)
                   000000000048b112: eb442000000c   srlg    %r4,%r4,0(%r2)
                   000000000048b118: ec243abf0055   risbg   %r2,%r4,58,191,0
                   000000000048b11e: ec12000500d9   aghik   %r1,%r2,5
                   000000000048b124: eb110003000d   sllg    %r1,%r1,3
[23023.010626] Call Trace:
[23023.010628] ([<000000531f9c8e10>] 0x531f9c8e10)
[23023.010632]  [<000000000027ca7a>] __delete_from_page_cache+0xaa/0x2d0
[23023.010638]  [<00000000002913d4>] __remove_mapping+0xd4/0x1e8
[23023.010643]  [<0000000000293476>] shrink_page_list+0x50e/0xc18
[23023.010646]  [<00000000002942ba>] shrink_inactive_list+0x202/0x628
[23023.010648]  [<0000000000294e74>] shrink_lruvec+0x36c/0x738
[23023.010650]  [<00000000002952de>] shrink_zone+0x9e/0x1f0
[23023.010653]  [<0000000000296540>] balance_pgdat+0x518/0x658
[23023.010655]  [<00000000002967f4>] kswapd+0x174/0x4a0
[23023.010658]  [<000000000017b03a>] kthread+0xea/0xf8
[23023.010663]  [<0000000000763a86>] kernel_thread_starter+0x6/0x10
[23023.010669]  [<0000000000763a80>] kernel_thread_starter+0x0/0x10
[23023.010671] Last Breaking-Event-Address:
[23023.010672]  [<000000000048cb3c>] __radix_tree_lookup+0x84/0x118
[23023.010677] Kernel panic - not syncing: Fatal exception: panic_on_oops


  • Red Hat Enterprise Linux 7.9 kernel-3.10.0-1160.el7.s390x
  • RHEL7 s390x KVM guest running on RHEL8.3 x390x KVM host
  • IBM s390x architecture

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