[DRBD-user] drbd-9.0.18-1 : BUG: unable to handle kernel NULL pointer dereference at 00000000000000b0

[Rob van der Wal]

drbd-9.0.18-1 does not seem to work with Suse Enterprise 12 SP4:
2019-06-03T09:34:26.602963+02:00 barentsz kern alert kernel - - - [ 
699.994957] BUG: unable to handle kernel NULL pointer dereference at 
00000000000000b0
2019-06-03T09:34:26.602964+02:00 barentsz kern alert kernel - - - [ 
699.996005] IP: drbd_md_decode+0x17/0x4f0 [drbd]
2019-06-03T09:34:26.602966+02:00 barentsz kern info kernel - - - [ 
699.997027] PGD 800000085a46a067 P4D 800000085a46a067 PUD 85ae11067 PMD 0
2019-06-03T09:34:26.602967+02:00 barentsz kern warning kernel - - - [  
699.998075] Oops: 0000 [#6] SMP PTI
2019-06-03T09:34:26.602969+02:00 barentsz kern warning kernel - - - [  
699.999118] CPU: 14 PID: 3179 Comm: drbdsetup Tainted: G D OE      
4.12.14-95.16-default #1 SLE12-SP4
2019-06-03T09:34:26.602970+02:00 barentsz kern warning kernel - - - [  
700.000204] Hardware name: Dell Inc. PowerEdge R630/02C2CP, BIOS 2.9.1 
12/04/2018
2019-06-03T09:34:26.602971+02:00 barentsz kern warning kernel - - - [  
700.001305] task: ffff9beddfab9900 task.stack: ffffb3f248898000
2019-06-03T09:34:26.602973+02:00 barentsz kern warning kernel - - - [  
700.002422] RIP: 0010:drbd_md_decode+0x17/0x4f0 [drbd]
2019-06-03T09:34:26.602974+02:00 barentsz kern warning kernel - - - [  
700.003539] RSP: 0018:ffffb3f24889ba90 EFLAGS: 00010286
2019-06-03T09:34:26.602975+02:00 barentsz kern warning kernel - - - [  
700.004659] RAX: 000000000000002c RBX: ffff9bedc463f800 RCX: 
0000000000000000
2019-06-03T09:34:26.602976+02:00 barentsz kern warning kernel - - - [  
700.005792] RDX: 0000000000000074 RSI: ffff9bedc463f800 RDI: 
ffff9bedd761f800
2019-06-03T09:34:26.602977+02:00 barentsz kern warning kernel - - - [  
700.006922] RBP: ffff9bedd761f800 R08: 0000000000000000 R09: 
0000000000000703
2019-06-03T09:34:26.602979+02:00 barentsz kern warning kernel - - - [  
700.008057] R10: 00000000000003ff R11: 0000000000aaaaaa R12: 
ffff9bedd7bfd158
2019-06-03T09:34:26.602980+02:00 barentsz kern warning kernel - - - [  
700.009194] R13: ffff9bedd7bfd000 R14: ffff9bedc463f800 R15: 
0000000000000074
2019-06-03T09:34:26.602981+02:00 barentsz kern warning kernel - - - [  
700.010328] FS:  00007f9c91edc700(0000) GS:ffff9beddf9c0000(0000) 
knlGS:0000000000000000
2019-06-03T09:34:26.602982+02:00 barentsz kern warning kernel - - - [  
700.011470] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
2019-06-03T09:34:26.602983+02:00 barentsz kern warning kernel - - - [  
700.012612] CR2: 00000000000000b0 CR3: 000000085922e002 CR4: 
00000000003606e0
2019-06-03T09:34:26.602984+02:00 barentsz kern warning kernel - - - [  
700.013770] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 
0000000000000000
2019-06-03T09:34:26.602986+02:00 barentsz kern warning kernel - - - [  
700.014928] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 
0000000000000400
2019-06-03T09:34:26.602987+02:00 barentsz kern warning kernel - - - [  
700.016082] Call Trace:
2019-06-03T09:34:26.602988+02:00 barentsz kern warning kernel - - - [  
700.017211]  ? printk+0x48/0x4a
2019-06-03T09:34:26.602989+02:00 barentsz kern warning kernel - - - [  
700.018320]  ? drbd_dax_open+0x76/0xc0 [drbd]
2019-06-03T09:34:26.602990+02:00 barentsz kern warning kernel - - - [  
700.019408]  drbd_md_read+0xbf/0x180 [drbd]
2019-06-03T09:34:26.602992+02:00 barentsz kern warning kernel - - - [  
700.020468]  drbd_adm_attach+0x40f/0x12c0 [drbd]
2019-06-03T09:34:26.602993+02:00 barentsz kern warning kernel - - - [  
700.021496]  ? get_disk+0x37/0x50
2019-06-03T09:34:26.602994+02:00 barentsz kern warning kernel - - - [  
700.022491]  genl_family_rcv_msg+0x1cb/0x390
2019-06-03T09:34:26.602995+02:00 barentsz kern warning kernel - - - [  
700.023461]  genl_rcv_msg+0x47/0x90
2019-06-03T09:34:26.602997+02:00 barentsz kern warning kernel - - - [  
700.024394]  ? genl_family_rcv_msg+0x390/0x390
2019-06-03T09:34:26.602998+02:00 barentsz kern warning kernel - - - [  
700.025303]  netlink_rcv_skb+0xd4/0x110
2019-06-03T09:34:26.602999+02:00 barentsz kern warning kernel - - - [  
700.026185]  genl_rcv+0x24/0x40
2019-06-03T09:34:26.603000+02:00 barentsz kern warning kernel - - - [  
700.027032]  netlink_unicast+0x15a/0x220
2019-06-03T09:34:26.603026+02:00 barentsz kern warning kernel - - - [  
700.027853]  netlink_sendmsg+0x2b5/0x3a0
2019-06-03T09:34:26.603028+02:00 barentsz kern warning kernel - - - [  
700.028662]  sock_sendmsg+0x36/0x50
2019-06-03T09:34:26.603029+02:00 barentsz kern warning kernel - - - [  
700.029463]  sock_write_iter+0x79/0xd0
2019-06-03T09:34:26.603030+02:00 barentsz kern warning kernel - - - [  
700.030260]  __vfs_write+0xdc/0x150
2019-06-03T09:34:26.603032+02:00 barentsz kern warning kernel - - - [  
700.031052]  vfs_write+0xad/0x1a0
2019-06-03T09:34:26.603033+02:00 barentsz kern warning kernel - - - [  
700.031839]  ? task_work_run+0x7d/0x90
2019-06-03T09:34:26.603034+02:00 barentsz kern warning kernel - - - [  
700.032617]  SyS_write+0x42/0x90
2019-06-03T09:34:26.603036+02:00 barentsz kern warning kernel - - - [  
700.033393]  ? exit_to_usermode_loop+0x86/0x9c
2019-06-03T09:34:26.603037+02:00 barentsz kern warning kernel - - - [  
700.034166]  do_syscall_64+0x74/0x160
2019-06-03T09:34:26.603038+02:00 barentsz kern warning kernel - - - [  
700.034935]  entry_SYSCALL_64_after_hwframe+0x3d/0xa2

The status of the drbd devices are "diskless" now. Any ideas?