Hi all, after installation of 5.4.0-47 I also got the impression that the bug was gone and was happy. Until now ... I'm getting this type of data corruption with the recent main focal kernel: Linux 5.4.0-47-generic #51-Ubuntu SMP Fri Sep 4 19:50:52 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux (relatively fresh Ubuntu 20.04 installation on ZFS after this bug hopelessly corrupted the old ext4 installation) Setup: * remote NFS4 + krb5 ( over Wifi) * local ZFS Trigger: * rsync'ing a large amount of data from ZFS (local) to NFS4 (remote) Workqueue: rpciod rpc_async_schedule [sunrpc] RIP: #1: 0010:kmem_cache_free+0x237/0x2b0 #2: 0010:kmem_cache_alloc+0x7e/0x230 Any idea? BR, Martin [198007.326710] ------------[ cut here ]------------ [198007.326711] virt_to_cache: Object is not a Slab page! [198007.326721] WARNING: CPU: 2 PID: 1317011 at mm/slab.h:473 kmem_cache_free+0x237/0x2b0 [198007.326722] Modules linked in: cx23885 altera_ci tda18271 altera_stapl m88ds3103 tveeprom cx2341x videobuf2_dvb dvb_core rc_core videobuf2_dma_sg videobuf2_memops videobuf2_v4l2 videobuf2_common btrfs xor zstd_compress raid6_pq ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs libcrc32c rpcsec_gss_krb5 auth_rpcgss nfsv4 nfs lockd grace fscache cmac algif_hash algif_skcipher af_alg bnep nls_iso8859_1 si2157 si2168 cx25840 i2c_mux snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio snd_hda_codec_hdmi videodev snd_hda_intel snd_intel_dspcfg mc snd_hda_codec snd_hda_core snd_hwdep mei_hdcp intel_rapl_msr snd_pcm snd_seq_midi snd_seq_midi_event intel_rapl_common x86_pkg_temp_thermal intel_powerclamp snd_rawmidi kvm_intel btusb btrtl snd_seq kvm btbcm btintel crct10dif_pclmul ghash_clmulni_intel aesni_intel crypto_simd eeepc_wmi cryptd glue_helper snd_seq_device snd_timer rapl intel_cstate bluetooth snd asus_wmi sparse_keymap ecdh_generic ecc wmi_bmof cdc_acm mei_me soundcore mei mac_hid [198007.326749] acpi_pad sch_fq_codel nct6775 hwmon_vid coretemp parport_pc ppdev lp parport sunrpc ip_tables x_tables autofs4 zfs(POE) zunicode(POE) zavl(POE) icp(POE) zcommon(POE) znvpair(POE) spl(OE) zlua(POE) hid_generic usbhid hid i915 i2c_algo_bit mxm_wmi crc32_pclmul drm_kms_helper ahci libahci syscopyarea r8169 lpc_ich i2c_i801 sysfillrect realtek sysimgblt fb_sys_fops drm wmi video [last unloaded: dvb_core] [198007.326765] CPU: 2 PID: 1317011 Comm: kworker/u8:3 Tainted: P OE 5.4.0-47-generic #51-Ubuntu [198007.326766] Hardware name: ASUS All Series/H97M-E, BIOS 2702 03/28/2016 [198007.326804] Workqueue: rpciod rpc_async_schedule [sunrpc] [198007.326809] RIP: 0010:kmem_cache_free+0x237/0x2b0 [198007.326810] Code: ff ff ff 80 3d a6 45 56 01 00 0f 85 39 ff ff ff 48 c7 c6 60 44 87 a5 48 c7 c7 00 2e b8 a5 c6 05 8b 45 56 01 01 e8 14 7f df ff <0f> 0b e9 18 ff ff ff 48 8b 57 58 49 8b 4f 58 48 c7 c6 70 44 87 a5 [198007.326811] RSP: 0018:ffffae38c34e3d20 EFLAGS: 00010282 [198007.326812] RAX: 0000000000000000 RBX: ffff927771c5355f RCX: 0000000000000006 [198007.326812] RDX: 0000000000000007 RSI: 0000000000000092 RDI: ffff9277d79178c0 [198007.326813] RBP: ffffae38c34e3d48 R08: 0000000000000b72 R09: 0000000000000004 [198007.326813] R10: 0000000000000000 R11: 0000000000000001 R12: ffff9277f1c5355f [198007.326814] R13: 0000000000000000 R14: ffff92774426d080 R15: ffff92779ea6acb0 [198007.326815] FS: 0000000000000000(0000) GS:ffff9277d7900000(0000) knlGS:0000000000000000 [198007.326815] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [198007.326816] CR2: 00007f19cc03b000 CR3: 00000000af60a005 CR4: 00000000001606e0 [198007.326816] Call Trace: [198007.326823] mempool_free_slab+0x17/0x20 [198007.326825] mempool_free+0x2f/0x80 [198007.326846] rpc_free+0x47/0x60 [sunrpc] [198007.326856] xprt_release+0x91/0x1a0 [sunrpc] [198007.326863] rpc_release_resources_task+0x13/0x50 [sunrpc] [198007.326869] __rpc_execute+0x182/0x3a0 [sunrpc] [198007.326875] rpc_async_schedule+0x30/0x50 [sunrpc] [198007.326877] process_one_work+0x1eb/0x3b0 [198007.326878] worker_thread+0x4d/0x400 [198007.326880] kthread+0x104/0x140 [198007.326881] ? process_one_work+0x3b0/0x3b0 [198007.326882] ? kthread_park+0x90/0x90 [198007.326885] ret_from_fork+0x35/0x40 [198007.326886] ---[ end trace c87e78ba40592766 ]--- [198010.422632] general protection fault: 0000 [#1] SMP PTI [198010.422637] CPU: 1 PID: 1321230 Comm: kworker/u8:5 Tainted: P W OE 5.4.0-47-generic #51-Ubuntu [198010.422638] Hardware name: ASUS All Series/H97M-E, BIOS 2702 03/28/2016 [198010.422661] Workqueue: rpciod rpc_async_schedule [sunrpc] [198010.422666] RIP: 0010:kmem_cache_alloc+0x7e/0x230 [198010.422668] Code: 99 01 00 00 4d 8b 07 65 49 8b 50 08 65 4c 03 05 a0 91 56 5b 4d 8b 20 4d 85 e4 0f 84 85 01 00 00 41 8b 47 20 49 8b 3f 4c 01 e0 <48> 8b 18 48 89 c1 49 33 9f 70 01 00 00 4c 89 e0 48 0f c9 48 31 cb [198010.422669] RSP: 0018:ffffae38e0a83cc8 EFLAGS: 00010206 [198010.422671] RAX: 7113d0192329439a RBX: 0000000000000000 RCX: 0000000000000002 [198010.422672] RDX: 000000000000004a RSI: 0000000000092800 RDI: 0000000000031ca0 [198010.422673] RBP: ffffae38e0a83cf8 R08: ffff9277d78b1ca0 R09: 0000000000000000 [198010.422674] R10: ffff92776f6aba2c R11: 0000000000000018 R12: 7113d0192329439a [198010.422675] R13: 0000000000092800 R14: ffff9277d61cefc0 R15: ffff9277d61cefc0 [198010.422677] FS: 0000000000000000(0000) GS:ffff9277d7880000(0000) knlGS:0000000000000000 [198010.422678] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [198010.422680] CR2: 00007f19cc00e000 CR3: 00000000af60a005 CR4: 00000000001606e0 [198010.422681] Call Trace: [198010.422685] ? mempool_alloc_slab+0x17/0x20 [198010.422688] mempool_alloc_slab+0x17/0x20 [198010.422691] mempool_alloc+0x64/0x180 [198010.422703] rpc_malloc+0xa1/0xb0 [sunrpc] [198010.422713] call_allocate+0xd1/0x1b0 [sunrpc] [198010.422722] ? call_refreshresult+0x100/0x100 [sunrpc] [198010.422731] __rpc_execute+0x8c/0x3a0 [sunrpc] [198010.422741] rpc_async_schedule+0x30/0x50 [sunrpc] [198010.422744] process_one_work+0x1eb/0x3b0 [198010.422746] worker_thread+0x4d/0x400 [198010.422749] kthread+0x104/0x140 [198010.422751] ? process_one_work+0x3b0/0x3b0 [198010.422753] ? kthread_park+0x90/0x90 [198010.422757] ret_from_fork+0x35/0x40 [198010.422759] Modules linked in: cx23885 altera_ci tda18271 altera_stapl m88ds3103 tveeprom cx2341x videobuf2_dvb dvb_core rc_core videobuf2_dma_sg videobuf2_memops videobuf2_v4l2 videobuf2_common btrfs xor zstd_compress raid6_pq ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs libcrc32c rpcsec_gss_krb5 auth_rpcgss nfsv4 nfs lockd grace fscache cmac algif_hash algif_skcipher af_alg bnep nls_iso8859_1 si2157 si2168 cx25840 i2c_mux snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio snd_hda_codec_hdmi videodev snd_hda_intel snd_intel_dspcfg mc snd_hda_codec snd_hda_core snd_hwdep mei_hdcp intel_rapl_msr snd_pcm snd_seq_midi snd_seq_midi_event intel_rapl_common x86_pkg_temp_thermal intel_powerclamp snd_rawmidi kvm_intel btusb btrtl snd_seq kvm btbcm btintel crct10dif_pclmul ghash_clmulni_intel aesni_intel crypto_simd eeepc_wmi cryptd glue_helper snd_seq_device snd_timer rapl intel_cstate bluetooth snd asus_wmi sparse_keymap ecdh_generic ecc wmi_bmof cdc_acm mei_me soundcore mei mac_hid [198010.422790] acpi_pad sch_fq_codel nct6775 hwmon_vid coretemp parport_pc ppdev lp parport sunrpc ip_tables x_tables autofs4 zfs(POE) zunicode(POE) zavl(POE) icp(POE) zcommon(POE) znvpair(POE) spl(OE) zlua(POE) hid_generic usbhid hid i915 i2c_algo_bit mxm_wmi crc32_pclmul drm_kms_helper ahci libahci syscopyarea r8169 lpc_ich i2c_i801 sysfillrect realtek sysimgblt fb_sys_fops drm wmi video [last unloaded: dvb_core] [198010.422841] ---[ end trace c87e78ba40592767 ]---