Is this known ops, reproducible 100% with garbage args to mount: mount -o vers=4.0,sec=shs <serverip>:/<mount> /mnt My kernel is commit: 0fecfcb9d4d2803079048df7946019463544414e I haven't bisets but seems to be a recent. My 5.5 kernel works. localhost login: [ 103.982099] BUG: unable to handle page fault for address: 0000000000020000 [ 103.987970] #PF: supervisor read access in kernel mode [ 103.990835] #PF: error_code(0x0000) - not-present page [ 103.993721] PGD 0 P4D 0 [ 103.995291] Oops: 0000 [#1] SMP PTI [ 103.997256] CPU: 0 PID: 3059 Comm: mount.nfs Not tainted 5.6.0-rc5+ #295 [ 104.000946] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018 [ 104.007360] RIP: 0010:strcmp+0xc/0x30 [ 104.009416] Code: 75 f7 48 83 c6 01 0f b6 4e ff 48 83 c2 01 84 c9 88 4a ff 75 ed f3 c3 0f 1f 80 00 00 00 00 48 83 c7 01 0f b6 47 ff 48 83 c6 01 <3a> 46 ff 75 07 84 c0 75 eb 31 c0 c3 19 c0 83 c8 01 0f 1f 00 c3 0f [ 104.019756] RSP: 0018:ffffc2a0c2207d50 EFLAGS: 00010202 [ 104.022659] RAX: 0000000000000073 RBX: ffffffffc0a4f1d0 RCX: 0000000000000000 [ 104.026742] RDX: 00000000ffffffff RSI: 0000000000020001 RDI: ffff9ffcabf71df9 [ 104.031161] RBP: ffff9ffcabf71df8 R08: 0000000000000000 R09: ffff9ffcabf71dfb [ 104.035410] R10: 000000000000003a R11: 657261687373666e R12: ffff9ffcabf71df8 [ 104.039755] R13: ffffc2a0c2207d80 R14: ffff9ffc22037834 R15: 0000000000000020 [ 104.044001] FS: 00007f8735790880(0000) GS:ffff9ffcb9e00000(0000) knlGS:0000000000000000 [ 104.048952] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 104.053260] CR: 0000000000020000 CR3: 0000000135210001 CR4: 00000000001606f0 [ 104.057233] Call Trace: [ 104.058646] __lookup_constant+0x2b/0x40 [ 104.060839] lookup_constant+0xd/0x20 [ 104.062928] nfs_fs_context_parse_param+0x1e9/0x920 [nfs] [ 104.065989] vfs_parse_fs_param+0xd3/0x190 [ 104.068303] vfs_parse_fs_string+0x75/0xb0 [ 104.070590] generic_parse_monolithic+0x8f/0xc0 [ 104.073155] nfs_fs_context_parse_monolithic+0x22b/0x670 [nfs] [ 104.076437] do_mount+0x626/0x970 [ 104.078655] __x64_sys_mount+0x86/0xd0 [ 104.081118] do_syscall_64+0x55/0x1f0 [ 104.083592] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 104.086903] RIP: 0033:0x7f8734e57aaa [ 104.089072] Code: 48 8b 0d e1 33 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ae 33 2c 00 f7 d8 64 89 01 48 [ 104.099612] RSP: 002b:00007ffe33f17ba8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 104.103917] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8734e57aaa [ 104.107913] RDX: 000056270a7cb260 RSI: 000056270a7cb240 RDI: 000056270a7cb280 [ 104.111876] RBP: 00007ffe33f17d20 R08: 000056270a7cb7c0 R09: 000000000000003b [ 104.115864] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe33f17d20 [ 104.119811] R13: 000056270a7cb520 R14: 0000000000000010 R15: 00007ffe33f17c30 [ 104.124019] Modules linked in: nfs rfcomm fuse bridge stp llc ip6t_rpfilter ipt_REJECT nf_reject_ipv4 ip6t_REJECT nf_reject_ipv6 xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ebtable_nat ebtable_broute ip6table_mangle ip6table_security ip6table_raw iptable_mangle iptable_security iptable_raw ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter bnep snd_seq_midi snd_seq_midi_event crct10dif_pclmul crc32_pclmul ghash_clmulni_intel btusb btrtl btbcm btintel bluetooth snd_ens1371 uvcvideo snd_ac97_codec aesni_intel ac97_bus glue_helper snd_seq crypto_simd cryptd videobuf2_vmalloc videobuf2_memops snd_pcm videobuf2_v4l2 vmw_balloon videodev vmw_vmci snd_timer snd_rawmidi pcspkr snd_seq_device snd videobuf2_common rfkill ecdh_generic i2c_piix4 ecc soundcore nfsd nfs_acl lockd auth_rpcgss grace sunrpc ip_tables xfs libcrc32c vmwgfx sr_mod sd_mod cdrom t10_pi ata_generic pata_acpi drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm ahci libahci ata_piix [ 104.124052] libata e1000 mptspi scsi_transport_spi i2c_core mptscsih crc32c_intel mptbase serio_raw dm_mirror dm_region_hash dm_log dm_mod [ 104.190925] CR2: 0000000000020000 [ 104.192989] ---[ end trace 870843230151cfc0 ]---
