Hi,
I have problem with drbd on gentoo-hardened, kernel versions 4.4.8-hardened-r1 and 4.6.5-hardened-r1.
[ 48.687425] drbd drbd_221: Starting worker thread (from drbdsetup-84 [2086])
[ 48.701378] block drbd221: disk( Diskless -> Attaching )
[ 48.706554] drbd drbd_221: Method to ensure write ordering: flush
[ 48.706558] block drbd221: max BIO size = 131072
[ 48.706569] block drbd221: drbd_bm_resize called with capacity == 949468800
[ 48.719252] block drbd221: resync bitmap: bits=118683600 words=1854432 pages=3622
[ 48.719260] block drbd221: size = 453 GB (474734400 KB)
[ 48.827657] block drbd221: recounting of set bits took additional 12 jiffies
[ 48.827664] block drbd221: 1048 MB (268288 bits) marked out-of-sync by on disk bit-map.
[ 48.827676] block drbd221: disk( Attaching -> UpToDate )
[ 48.827681] block drbd221: attached to UUIDs 1CFE6629346C774C:0000000000000000:6521C977FB0CAB0F:6520C977FB0CAB0F
[ 48.892490] drbd drbd_222: Starting worker thread (from drbdsetup-84 [2092])
[ 48.893302] block drbd222: disk( Diskless -> Attaching )
[ 48.893495] drbd drbd_222: Method to ensure write ordering: flush
[ 48.893499] block drbd222: max BIO size = 131072
[ 48.893507] block drbd222: drbd_bm_resize called with capacity == 949468800
[ 48.911321] block drbd222: resync bitmap: bits=118683600 words=1854432 pages=3622
[ 48.911330] block drbd222: size = 453 GB (474734400 KB)
[ 49.001425] block drbd222: recounting of set bits took additional 11 jiffies
[ 49.001432] block drbd222: 353 GB (92510160 bits) marked out-of-sync by on disk bit-map.
[ 49.001453] block drbd222: disk( Attaching -> Inconsistent )
[ 49.001458] block drbd222: attached to UUIDs 0002000000000004:0000000000000000:886DC0F7ABE4AB02:0000000000000000
[ 49.010862] drbd drbd_221: conn( StandAlone -> Unconnected )
[ 49.010981] drbd drbd_221: Starting receiver thread (from drbd_w_drbd_221 [2087])
[ 49.011459] drbd drbd_221: receiver (re)started
[ 49.011499] drbd drbd_221: conn( Unconnected -> WFConnection )
[ 49.021504] drbd drbd_222: conn( StandAlone -> Unconnected )
[ 49.021546] drbd drbd_222: Starting receiver thread (from drbd_w_drbd_222 [2094])
[ 49.022262] drbd drbd_222: receiver (re)started
[ 49.022297] drbd drbd_222: conn( Unconnected -> WFConnection )
[ 49.571570] drbd drbd_221: initial packet S crossed
[ 49.571712] drbd drbd_222: initial packet S crossed
[ 59.143277] drbd drbd_221: Handshake successful: Agreed network protocol version 101
[ 59.143284] drbd drbd_221: Agreed to support TRIM on protocol level
[ 59.143339] drbd drbd_221: conn( WFConnection -> WFReportParams )
[ 59.143343] drbd drbd_221: Starting asender thread (from drbd_r_drbd_221 [2098])
[ 59.157149] block drbd221: drbd_sync_handshake:
[ 59.157157] block drbd221: self 1CFE6629346C774C:0000000000000000:6521C977FB0CAB0F:6520C977FB0CAB0F bits:268288 flags:0
[ 59.157161] block drbd221: peer 1CFE6629346C774C:0000000000000000:6521C977FB0CAB0E:6520C977FB0CAB0F bits:0 flags:0
[ 59.157164] block drbd221: uuid_compare()=1 by rule 40
[ 59.157175] block drbd221: peer( Unknown -> Secondary ) conn( WFReportParams -> WFBitMapS ) pdsk( DUnknown -> Consistent )
[ 59.157306] PAX: size overflow detected in function drbd_send_bitmap drivers/block/drbd/drbd_main.c:1072 cicus.1244_488 min, count: 102, decl: encoding; num: 0; context: p_compressed_bm;
[ 59.158357] CPU: 0 PID: 2087 Comm: drbd_w_drbd_221 Not tainted 4.4.8-hardened-r1-fx #2
[ 59.158360] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[ 59.158363] 0000000000000000 ffffc90000833cc0 ffffffff813ef95f 0000000000000001
[ 59.158367] ffffffffa0052918 0000000000000430 ffffc90000833cf0 ffffffff8116134e
[ 59.158370] ffff88007f976011 ffff88007f976010 0000000000000000 ffff8800bba3a000
[ 59.158374] Call Trace:
[ 59.158420] [<ffffffff813ef95f>] dump_stack+0x4e/0x7f
[ 59.158435] [<ffffffffa0052918>] ? put_ldev+0x8001/0x15628 [drbd]
[ 59.158458] [<ffffffff8116134e>] report_size_overflow+0x6e/0x80
[ 59.158466] [<ffffffffa00374da>] drbd_send_bitmap+0x68a/0xb80 [drbd]
[ 59.158470] [<ffffffff8114406d>] ? kfree+0x1d/0x100
[ 59.158477] [<ffffffffa003005b>] w_bitmap_io+0x11b/0x350 [drbd]
[ 59.158483] [<ffffffffa0019649>] drbd_worker+0xe9/0x3a0 [drbd]
[ 59.158490] [<ffffffffa002f930>] ? drbd_destroy_connection+0xf0/0xf0 [drbd]
[ 59.158496] [<ffffffffa002f988>] drbd_thread_setup+0x58/0x170 [drbd]
[ 59.158502] [<ffffffffa002f930>] ? drbd_destroy_connection+0xf0/0xf0 [drbd]
[ 59.158519] [<ffffffff81072415>] kthread+0xd5/0xf0
[ 59.158523] [<ffffffff81072340>] ? kthread_create_on_node+0x170/0x170
[ 59.158555] [<ffffffff817b3bfe>] ret_from_fork+0x3e/0x70
[ 59.158559] [<ffffffff81072340>] ? kthread_create_on_node+0x170/0x170
[ 61.500228] drbd drbd_222: initial packet M crossed
[ 62.501253] drbd drbd_222: Handshake successful: Agreed network protocol version 101
[ 62.501258] drbd drbd_222: Agreed to support TRIM on protocol level
[ 62.501316] drbd drbd_222: conn( WFConnection -> WFReportParams )
[ 62.501328] drbd drbd_222: Starting asender thread (from drbd_r_drbd_222 [2100])
[ 62.515144] block drbd222: drbd_sync_handshake:
[ 62.515150] block drbd222: self 0002000000000004:0000000000000000:886DC0F7ABE4AB02:0000000000000000 bits:92510160 flags:0
[ 62.515154] block drbd222: peer 96FF4A6DA7C16B9F:0002000000000005:0001000000000005:0000000000000005 bits:92731314 flags:0
[ 62.515158] block drbd222: uuid_compare()=-1 by rule 50
[ 62.515161] block drbd222: Becoming sync target due to disk states.
[ 62.515168] block drbd222: peer( Unknown -> Primary ) conn( WFReportParams -> WFBitMapT ) pdsk( DUnknown -> UpToDate )
[ 62.785144] block drbd222: receive bitmap stats [Bytes(packets)]: plain 0(0), RLE 65(1), total 65; compression: 100.0%
[ 62.790408] block drbd222: send bitmap stats [Bytes(packets)]: plain 0(0), RLE 65(1), total 65; compression: 100.0%
[ 62.790422] block drbd222: conn( WFBitMapT -> WFSyncUUID )
[ 62.826388] block drbd222: updated sync uuid 0003000000000004:0000000000000000:886DC0F7ABE4AB02:0000000000000000
[ 62.827356] block drbd222: helper command: /sbin/drbdadm before-resync-target minor-222
[ 62.839333] block drbd222: helper command: /sbin/drbdadm before-resync-target minor-222 exit code 0 (0x0)
[ 62.839354] block drbd222: conn( WFSyncUUID -> SyncTarget )
[ 62.839375] block drbd222: Began resync as SyncTarget (will sync 370965192 KB [92741298 bits set]).