# DRBD bitmap resize/unlock race leads to BUG at mm/slub.c:553 during detach (9.2.16)

**URL:** <https://forums.linbit.com/t/drbd-bitmap-resize-unlock-race-leads-to-bug-at-mm-slub-c-553-during-detach-9-2-16/1146>\
**Category:** DRBD\
**Tags:** drbd\
**Created:** [February 2, 2026, 2:59pm UTC](https://forums.linbit.com/t/drbd-bitmap-resize-unlock-race-leads-to-bug-at-mm-slub-c-553-during-detach-9-2-16/1146 "2026-02-02T14:59:16Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![jakub](https://avatars.discourse-cdn.com/v4/letter/j/ecb155/32.png) [@jakub](https://forums.linbit.com/u/jakub)\
**Post date:** [February 2, 2026, 2:59pm UTC](https://forums.linbit.com/t/drbd-bitmap-resize-unlock-race-leads-to-bug-at-mm-slub-c-553-during-detach-9-2-16/1146/1 "2026-02-02T14:59:17Z")

</div>

# Hi everyone,

My system hit a kernel BUG in the slab free path while DRBD was detaching; crash collected from pstore after reboot.

### Versions

```plaintext
DRBD_KERNEL_VERSION_CODE=0x090210
DRBD_KERNEL_VERSION=9.2.16
DRBDADM_VERSION_CODE=0x092100
DRBDADM_VERSION=9.33.0
Kernel: 6.8.0-100-generic (x86_64)

```

### Minimal crash excerpt (sanitised)

```plaintext
drbd ...: drbd_bm_resize called with capacity == 0
drbd ...: drbdsetup[PID] going to 'resize' but bitmap already locked for 'resize' by [PID]
drbd ...: FIXME no bitmap in drbd_bm_unlock!?
------------[cut here]------------
kernel BUG at mm/slub.c:553!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
Tainted: P OE
RIP: __slab_free+0x152/0x2c0
Call Trace:
drbd_bm_unlock [drbd]
drbd_bm_free [drbd]
kfree
drbd_bm_free [drbd]
drbd_cleanup_device [drbd]
adm_detach [drbd]
drbd_adm_down [drbd]
genl_family_rcv_msg_doit
...
Kernel panic - not syncing: Fatal exception

```

## Questions

- Is this a known issue in DRBD 9.2.16 around bitmap resize/unlock during detach?

- Any patches/workarounds or recommended upgrade path?

## More Details:

> **global\_common.conf**
>
> ```
> global {
> usage-count no;
> udev-always-use-vnr;
> disable-ip-verification;
> }
> common {
> protocol C;
> handlers {
> pri-on-incon-degr "/usr/lib/drbd/notify-pri-on-incon-degr.sh; /usr/lib/drbd/notify-emergency-reboot.sh; echo b > /proc/sysrq-trigger ; reboot -f";
> pri-lost-after-sb "/usr/lib/drbd/notify-pri-lost-after-sb.sh; /usr/lib/drbd/notify-emergency-reboot.sh; echo b > /proc/sysrq-trigger ; reboot -f";
> local-io-error "/usr/lib/drbd/notify-io-error.sh; /usr/lib/drbd/notify-emergency-shutdown.sh; echo o > /proc/sysrq-trigger ; halt -f";
> }
> startup {
> wfc-timeout 1;
> }
> options {
> }
> disk {
> c-fill-target 1M;
> c-max-rate 4096M;
> c-min-rate 1365M;
> resync-rate 1365M;
> on-io-error detach;
> al-extents 1297;
> }
> net {
> after-sb-0pri discard-zero-changes;
> after-sb-1pri consensus;
> after-sb-2pri disconnect;
> rr-conflict call-pri-lost;
> max-buffers 8000;
> max-epoch-size 8000;
> sndbuf-size 0;
> csums-alg md5;
> timeout 60;
> ko-count 7;
> verify-alg sha256;
> }
> }
> 
> ```

> **dmesg drbd context**
>
> ```
> 1-<6>[4700.075659] drbd <UUID>-1-dat: State change 387530487: primary_nodes=0, weak_nodes=0
> 2-<6>[4700.075663] drbd <UUID>-1-dat: Committing cluster-wide state change 387530487 (1ms)
> 3-<6>[4700.075674] drbd <UUID>-1-dat: role( Primary -> Secondary ) [down]
> 4-<6>[4700.076110] drbd <UUID>-1-dat: Preparing cluster-wide state change 2603503618: 1->0 conn( Disconnecting )
> 5-<6>[4700.076608] drbd <UUID>-1-dat: State change 2603503618: primary_nodes=0, weak_nodes=0
> 6-<6>[4700.076611] drbd <UUID>-1-dat <PEER>: Cluster is now split
> 7-<6>[4700.076613] drbd <UUID>-1-dat: Committing cluster-wide state change 2603503618 (1ms)
> 8-<6>[4700.076623] drbd <UUID>-1-dat <PEER>: conn( Connected -> Disconnecting ) peer( Secondary -> Unknown ) [down]
> 9-<6>[4700.076626] drbd <UUID>-1-dat/0 drbd1016 <PEER>: pdsk( UpToDate -> DUnknown ) repl( Established -> Off ) [down]
> 10-<6>[4700.076688] drbd <UUID>-1-dat <PEER>: Terminating sender thread
> 11-<6>[4700.076737] drbd <UUID>-1-dat <PEER>: Starting sender thread (peer-node-id 0)
> 12-<6>[4700.085136] drbd <UUID>-1-dat <PEER>: Connection closed
> 13-<6>[4700.085145] drbd <UUID>-1-dat <PEER>: helper command: /sbin/drbdadm disconnected
> 14-<6>[4700.085765] drbd /unregistered/<UUID>-1-cfg: Terminating worker thread
> 15-<4>[4705.112481] drbd <UUID>-1-dat <PEER>: helper command: /sbin/drbdadm disconnected exit code 20 (0x1400)
> 16-<6>[4705.112526] drbd <UUID>-1-dat <PEER>: conn( Disconnecting -> StandAlone ) [disconnected]
> 17-<6>[4705.112532] drbd <UUID>-1-dat <PEER>: Terminating receiver thread
> 18-<6>[4705.112577] drbd <UUID>-1-dat <PEER>: Terminating sender thread
> 19-<6>[4705.223555] drbd <UUID>-1-dat/0 drbd1016: disk( UpToDate -> Detaching ) [down]
> 20:<6>[4705.223596] drbd <UUID>-1-dat/0 drbd1016: drbd_bm_resize called with capacity == 0
> 21:<6>[4705.223611] drbd <UUID>-1-dat/0 drbd1016: disk( Detaching -> Diskless ) [go-diskless]
> 22-<6>[4705.753250] drbd <UUID>-1-cfg: Preparing cluster-wide state change 2054929065: 1->all role( Secondary )
> 23-<6>[4705.753544] drbd <UUID>-1-cfg: State change 2054929065: primary_nodes=0, weak_nodes=0
> 24-<6>[4705.753549] drbd <UUID>-1-cfg: Committing cluster-wide state change 2054929065 (1ms)
> 25-<6>[4705.753573] drbd <UUID>-1-cfg: role( Primary -> Secondary ) [down]
> 26-<6>[4705.754147] drbd <UUID>-1-cfg: Preparing cluster-wide state change 2617385148: 1->0 conn( Disconnecting )
> 27-<6>[4705.754596] drbd <UUID>-1-cfg: State change 2617385148: primary_nodes=0, weak_nodes=0
> 28-<6>[4705.754599] drbd <UUID>-1-cfg <PEER>: Cluster is now split
> 29-<6>[4705.754600] drbd <UUID>-1-cfg: Committing cluster-wide state change 2617385148 (1ms)
> 30-<6>[4705.754611] drbd <UUID>-1-cfg <PEER>: conn( Connected -> Disconnecting ) peer( Secondary -> Unknown ) [down]
> 31-<6>[4705.754613] drbd <UUID>-1-cfg/0 drbd1017 <PEER>: pdsk( UpToDate -> DUnknown ) repl( Established -> Off ) [down]
> 32-<6>[4705.754696] drbd <UUID>-1-cfg <PEER>: Terminating sender thread
> 33-<6>[4705.754720] drbd <UUID>-1-cfg <PEER>: Starting sender thread (peer-node-id 0)
> 34-<6>[4705.763647] drbd /unregistered/<UUID>-1-dat: Terminating worker thread
> 35-<6>[4705.786874] drbd <UUID>-1-cfg <PEER>: Connection closed
> 36-<6>[4705.786884] drbd <UUID>-1-cfg <PEER>: helper command: /sbin/drbdadm disconnected
> 37-<4>[4710.817100] drbd <UUID>-1-cfg <PEER>: helper command: /sbin/drbdadm disconnected exit code 20 (0x1400)
> 38-<6>[4710.817132] drbd <UUID>-1-cfg <PEER>: conn( Disconnecting -> StandAlone ) [disconnected]
> 39-<6>[4710.817138] drbd <UUID>-1-cfg <PEER>: Terminating receiver thread
> 40-<6>[4710.817184] drbd <UUID>-1-cfg <PEER>: Terminating sender thread
> 41-<6>[4710.928457] drbd <UUID>-1-cfg/0 drbd1017: disk( UpToDate -> Detaching ) [down]
> 42:<6>[4710.928501] drbd <UUID>-1-cfg/0 drbd1017: drbd_bm_resize called with capacity == 0
> 43:<6>[4710.928532] drbd <UUID>-1-cfg/0 drbd1017: disk( Detaching -> Diskless ) [go-diskless]
> 44-<6>[4711.272189] drbd <UUID>-1-dat: Preparing cluster-wide state change 14124492: 1->all role( Secondary )
> 45-<6>[4711.272477] drbd <UUID>-1-dat: State change 14124492: primary_nodes=0, weak_nodes=0
> 46-<6>[4711.272481] drbd <UUID>-1-dat: Committing cluster-wide state change 14124492 (1ms)
> 47-<6>[4711.272493] drbd <UUID>-1-dat: role( Primary -> Secondary ) [down]
> 48-<6>[4711.275883] drbd <UUID>-1-dat: Preparing cluster-wide state change 853377929: 1->0 conn( Disconnecting )
> 49-<6>[4711.276409] drbd <UUID>-1-dat: State change 853377929: primary_nodes=0, weak_nodes=0
> 50-<6>[4711.276415] drbd <UUID>-1-dat <PEER>: Cluster is now split
> 51-<6>[4711.276417] drbd <UUID>-1-dat: Committing cluster-wide state change 853377929 (1ms)
> 52-<6>[4711.276440] drbd <UUID>-1-dat <PEER>: conn( Connected -> Disconnecting ) peer( Secondary -> Unknown ) [down]
> 53-<6>[4711.276444] drbd <UUID>-1-dat/0 drbd1018 <PEER>: pdsk( UpToDate -> DUnknown ) repl( Established -> Off ) [down]
> 54-<6>[4711.276518] drbd <UUID>-1-dat <PEER>: Terminating sender thread
> 55-<6>[4711.276561] drbd <UUID>-1-dat <PEER>: Starting sender thread (peer-node-id 0)
> 56-<6>[4711.323411] drbd /unregistered/<UUID>-1-cfg: Terminating worker thread
> 57-<6>[4711.362143] drbd <UUID>-1-dat <PEER>: Connection closed
> 58-<6>[4711.362153] drbd <UUID>-1-dat <PEER>: helper command: /sbin/drbdadm disconnected
> 59-<4>[4716.389736] drbd <UUID>-1-dat <PEER>: helper command: /sbin/drbdadm disconnected exit code 20 (0x1400)
> 60-<6>[4716.389765] drbd <UUID>-1-dat <PEER>: conn( Disconnecting -> StandAlone ) [disconnected]
> 61-<6>[4716.389771] drbd <UUID>-1-dat <PEER>: Terminating receiver thread
> 62-<6>[4716.389821] drbd <UUID>-1-dat <PEER>: Terminating sender thread
> 63-<6>[4716.464353] drbd <UUID>-1-dat/0 drbd1018: disk( UpToDate -> Detaching ) [down]
> 64:<6>[4716.464393] drbd <UUID>-1-dat/0 drbd1018: drbd_bm_resize called with capacity == 0
> 65:<6>[4716.464412] drbd <UUID>-1-dat/0 drbd1018: disk( Detaching -> Diskless ) [go-diskless]
> 66-<6>[4717.012026] drbd <UUID>-1-cfg: Preparing cluster-wide state change 1636666767: 1->all role( Secondary )
> 67-<6>[4717.012313] drbd <UUID>-1-cfg: State change 1636666767: primary_nodes=0, weak_nodes=0
> 68-<6>[4717.012317] drbd <UUID>-1-cfg: Committing cluster-wide state change 1636666767 (1ms)
> 69-<6>[4717.012329] drbd <UUID>-1-cfg: role( Primary -> Secondary ) [down]
> 70-<6>[4717.012748] drbd <UUID>-1-cfg: Preparing cluster-wide state change 2101862626: 1->0 conn( Disconnecting )
> 71-<6>[4717.013246] drbd <UUID>-1-cfg: State change 2101862626: primary_nodes=0, weak_nodes=0
> 72-<6>[4717.013248] drbd <UUID>-1-cfg <PEER>: Cluster is now split
> 73-<6>[4717.013250] drbd <UUID>-1-cfg: Committing cluster-wide state change 2101862626 (0ms)
> 74-<6>[4717.013260] drbd <UUID>-1-cfg <PEER>: conn( Connected -> Disconnecting ) peer( Secondary -> Unknown ) [down]
> 75-<6>[4717.013263] drbd <UUID>-1-cfg/0 drbd1019 <PEER>: pdsk( UpToDate -> DUnknown ) repl( Established -> Off ) [down]
> 76-<6>[4717.013324] drbd <UUID>-1-cfg <PEER>: Terminating sender thread
> 77-<6>[4717.013349] drbd <UUID>-1-cfg <PEER>: Starting sender thread (peer-node-id 0)
> 78-<6>[4717.014307] drbd /unregistered/<UUID>-1-dat: Terminating worker thread
> 79-<6>[4717.063875] drbd <UUID>-1-cfg <PEER>: Connection closed
> 80-<6>[4717.063885] drbd <UUID>-1-cfg <PEER>: helper command: /sbin/drbdadm disconnected
> 81-<4>[4722.090674] drbd <UUID>-1-cfg <PEER>: helper command: /sbin/drbdadm disconnected exit code 20 (0x1400)
> 82-<6>[4722.090703] drbd <UUID>-1-cfg <PEER>: conn( Disconnecting -> StandAlone ) [disconnected]
> 83-<6>[4722.090709] drbd <UUID>-1-cfg <PEER>: Terminating receiver thread
> 84-<6>[4722.090750] drbd <UUID>-1-cfg <PEER>: Terminating sender thread
> 85-<6>[4722.217306] drbd <UUID>-1-cfg/0 drbd1019: disk( UpToDate -> Detaching ) [down]
> 86:<6>[4722.217349] drbd <UUID>-1-cfg/0 drbd1019: drbd_bm_resize called with capacity == 0
> 87:<6>[4722.217379] drbd <UUID>-1-cfg/0 drbd1019: disk( Detaching -> Diskless ) [go-diskless]
> 88-<6>[4722.562829] drbd <UUID>-1-dat: Preparing cluster-wide state change 3782904909: 1->all role( Secondary )
> 89-<6>[4722.563121] drbd <UUID>-1-dat: State change 3782904909: primary_nodes=0, weak_nodes=0
> 90-<6>[4722.563125] drbd <UUID>-1-dat: Committing cluster-wide state change 3782904909 (0ms)
> 91-<6>[4722.563136] drbd <UUID>-1-dat: role( Primary -> Secondary ) [down]
> 92-<6>[4722.563588] drbd <UUID>-1-dat: Preparing cluster-wide state change 3736661964: 1->0 conn( Disconnecting )
> 93-<6>[4722.564072] drbd <UUID>-1-dat: State change 3736661964: primary_nodes=0, weak_nodes=0
> 94-<6>[4722.564076] drbd <UUID>-1-dat <PEER>: Cluster is now split
> 95-<6>[4722.564077] drbd <UUID>-1-dat: Committing cluster-wide state change 3736661964 (0ms)
> 96-<6>[4722.564089] drbd <UUID>-1-dat <PEER>: conn( Connected -> Disconnecting ) peer( Secondary -> Unknown ) [down]
> 97-<6>[4722.564092] drbd <UUID>-1-dat/0 drbd1020 <PEER>: pdsk( UpToDate -> DUnknown ) repl( Established -> Off ) [down]
> 98-<6>[4722.564159] drbd <UUID>-1-dat <PEER>: Terminating sender thread
> 99-<6>[4722.564198] drbd <UUID>-1-dat <PEER>: Starting sender thread (peer-node-id 0)
> 100-<6>[4722.565237] drbd /unregistered/<UUID>-1-cfg: Terminating worker thread
> 101-<6>[4722.614579] drbd <UUID>-1-dat <PEER>: Connection closed
> 102-<6>[4722.614588] drbd <UUID>-1-dat <PEER>: helper command: /sbin/drbdadm disconnected
> 103-<4>[4727.641429] drbd <UUID>-1-dat <PEER>: helper command: /sbin/drbdadm disconnected exit code 20 (0x1400)
> 104-<6>[4727.641457] drbd <UUID>-1-dat <PEER>: conn( Disconnecting -> StandAlone ) [disconnected]
> 105-<6>[4727.641462] drbd <UUID>-1-dat <PEER>: Terminating receiver thread
> 106-<6>[4727.641524] drbd <UUID>-1-dat <PEER>: Terminating sender thread
> 107-<6>[4727.758177] drbd <UUID>-1-dat/0 drbd1020: disk( UpToDate -> Detaching ) [down]
> 108:<6>[4727.758209] drbd <UUID>-1-dat/0 drbd1020: drbd_bm_resize called with capacity == 0
> 109:<6>[4727.758225] drbd <UUID>-1-dat/0 drbd1020: disk( Detaching -> Diskless ) [go-diskless]
> 110-<6>[4728.363916] drbd <UUID>-1-cfg: Preparing cluster-wide state change 1750581167: 1->all role( Secondary )
> 111-<6>[4728.364200] drbd <UUID>-1-cfg: State change 1750581167: primary_nodes=0, weak_nodes=0
> 112-<6>[4728.364203] drbd <UUID>-1-cfg: Committing cluster-wide state change 1750581167 (1ms)
> 113-<6>[4728.364217] drbd <UUID>-1-cfg: role( Primary -> Secondary ) [down]
> 114-<6>[4728.364651] drbd <UUID>-1-cfg: Preparing cluster-wide state change 1491318722: 1->0 conn( Disconnecting )
> 115-<6>[4728.365169] drbd <UUID>-1-cfg: State change 1491318722: primary_nodes=0, weak_nodes=0
> 116-<6>[4728.365172] drbd <UUID>-1-cfg <PEER>: Cluster is now split
> 117-<6>[4728.365174] drbd <UUID>-1-cfg: Committing cluster-wide state change 1491318722 (1ms)
> 118-<6>[4728.365185] drbd <UUID>-1-cfg <PEER>: conn( Connected -> Disconnecting ) peer( Secondary -> Unknown ) [down]
> 119-<6>[4728.365187] drbd <UUID>-1-cfg/0 drbd1011 <PEER>: pdsk( UpToDate -> DUnknown ) repl( Established -> Off ) [down]
> 120-<6>[4728.365251] drbd <UUID>-1-cfg <PEER>: Terminating sender thread
> 121-<6>[4728.365262] drbd <UUID>-1-cfg <PEER>: Starting sender thread (peer-node-id 0)
> 122-<6>[4728.381100] drbd /unregistered/<UUID>-1-dat: Terminating worker thread
> 123-<6>[4728.384531] drbd <UUID>-1-cfg <PEER>: Connection closed
> 124-<6>[4728.384541] drbd <UUID>-1-cfg <PEER>: helper command: /sbin/drbdadm disconnected
> 125-<4>[4733.411782] drbd <UUID>-1-cfg <PEER>: helper command: /sbin/drbdadm disconnected exit code 20 (0x1400)
> 126-<6>[4733.411809] drbd <UUID>-1-cfg <PEER>: conn( Disconnecting -> StandAlone ) [disconnected]
> 127-<6>[4733.411814] drbd <UUID>-1-cfg <PEER>: Terminating receiver thread
> 128-<6>[4733.411877] drbd <UUID>-1-cfg <PEER>: Terminating sender thread
> 129-<6>[4733.496021] drbd <UUID>-1-cfg/0 drbd1011: disk( UpToDate -> Detaching ) [down]
> 130:<6>[4733.496055] drbd <UUID>-1-cfg/0 drbd1011: drbd_bm_resize called with capacity == 0
> 131:<6>[4733.496130] drbd <UUID>-1-cfg/0 drbd1011: disk( Detaching -> Diskless ) [go-diskless]
> 132-<6>[4733.742527] drbd <UUID>-1-dat: Preparing cluster-wide state change 3753270375: 1->all role( Secondary )
> 133-<6>[4733.742814] drbd <UUID>-1-dat: State change 3753270375: primary_nodes=0, weak_nodes=0
> 134-<6>[4733.742818] drbd <UUID>-1-dat: Committing cluster-wide state change 3753270375 (0ms)
> 135-<6>[4733.742829] drbd <UUID>-1-dat: role( Primary -> Secondary ) [down]
> 136-<6>[4733.743338] drbd <UUID>-1-dat: Preparing cluster-wide state change 793365399: 1->0 conn( Disconnecting )
> 137-<6>[4733.743781] drbd <UUID>-1-dat: State change 793365399: primary_nodes=0, weak_nodes=0
> 138-<6>[4733.743784] drbd <UUID>-1-dat <PEER>: Cluster is now split
> 139-<6>[4733.743786] drbd <UUID>-1-dat: Committing cluster-wide state change 793365399 (0ms)
> 140-<6>[4733.743797] drbd <UUID>-1-dat <PEER>: conn( Connected -> Disconnecting ) peer( Secondary -> Unknown ) [down]
> 141-<6>[4733.743800] drbd <UUID>-1-dat/0 drbd1012 <PEER>: pdsk( UpToDate -> DUnknown ) repl( Established -> Off ) [down]
> 142-<6>[4733.743859] drbd <UUID>-1-dat <PEER>: Terminating sender thread
> 143-<6>[4733.743881] drbd <UUID>-1-dat <PEER>: Starting sender thread (peer-node-id 0)
> 144-<6>[4733.765446] drbd <UUID>-1-dat <PEER>: Connection closed
> 145-<6>[4733.765455] drbd <UUID>-1-dat <PEER>: helper command: /sbin/drbdadm disconnected
> 146-<6>[4733.766002] drbd /unregistered/<UUID>-1-cfg: Terminating worker thread
> 147-<4>[4738.792327] drbd <UUID>-1-dat <PEER>: helper command: /sbin/drbdadm disconnected exit code 20 (0x1400)
> 148-<6>[4738.792356] drbd <UUID>-1-dat <PEER>: conn( Disconnecting -> StandAlone ) [disconnected]
> 149-<6>[4738.792361] drbd <UUID>-1-dat <PEER>: Terminating receiver thread
> 150-<6>[4738.792417] drbd <UUID>-1-dat <PEER>: Terminating sender thread
> 151-<6>[4738.931939] drbd <UUID>-1-dat/0 drbd1012: disk( UpToDate -> Detaching ) [down]
> 152:<6>[4738.931985] drbd <UUID>-1-dat/0 drbd1012: drbd_bm_resize called with capacity == 0
> 153-<4>[4738.932000] drbd <UUID>-1-dat/0 drbd1012: drbdsetup[588101] going to 'resize' but bitmap already locked for 'resize' by [42891]
> 154:<6>[4738.932003] drbd <UUID>-1-dat/0 drbd1012: disk( Detaching -> Diskless ) [go-diskless]
> 155:<6>[4738.932005] drbd <UUID>-1-dat/0 drbd1012: drbd_bm_resize called with capacity == 0
> 156:<3>[4738.932008] drbd <UUID>-1-dat/0 drbd1012: FIXME no bitmap in drbd_bm_unlock!?
> 157-<4>[4738.932378] ------------[cut here]------------
> 
> ```

> **oops**
>
> ```
> <4>[4738.932378] ------------[cut here]------------
> <2>[4738.932381] kernel BUG at mm/slub.c:553!
> <4>[4738.932697] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
> <4>[4738.933000] CPU: 2 PID: <PID> Comm: drbdsetup Tainted: P OE 6.8.0-100-generic
> <4>[4738.933310] Hardware name: Dell Inc. PowerEdge T440/021KCD, BIOS 2.4.8 11/27/2019
> <4>[4738.933611] RIP: e030:__slab_free+0x152/0x2c0
> <4>[4738.933897] Code: 00 4c 89 ff e8 4f 43 dd 00 48 8b 14 24 48 8b 4c 24 20 48 89 44 24 08 48 8b 03 48 c1 e8 09 83 e0 01 88 44 24 13 e9 71 ff ff ff <0f> 0b 41 f7 44 24 08 00 0d 21 00 75 b2 eb a8 41 f7 44 24 08 00 0d
> <4>[4738.934477] RSP: e02b:ffffc9007153b5d0 EFLAGS: 00010246
> <4>[4738.934773] RAX: ffff8881d4b4fe00 RBX: ffffea000752d200 RCX: 000000008020001a
> <4>[4738.935068] RDX: ffff8881d4b4fc00 RSI: ffffea000752d200 RDI: ffffc9007153b640
> <4>[4738.935367] RBP: ffffc9007153b670 R08: 0000000000000001 R09: ffffffffc1011a3c
> <4>[4738.935662] R10: 0000000000000000 R11: 0000000000000000 R12: ffff888100049300
> <4>[4738.935955] R13: ffff8881d4b4fc00 R14: ffffffffc1011a3c R15: ffff8881024b31c0
> <4>[4738.936255] FS: 0000703c46fcf740(0000) GS:ffff8890a1b00000(0000) knlGS:0000000000000000
> <4>[4738.936556] CS: e030 DS: 0000 ES: 0000 CR0: 0000000080050033
> <4>[4738.936853] CR2: 00007217cfff2938 CR3: 00000001d3a70000 CR4: 0000000000050660
> <4>[4738.937156] Call Trace:
> <4>[4738.937452] <TASK>
> <4>[4738.937745] ? drbd_bm_unlock+0xf9/0x110 [drbd]
> <4>[4738.938062] ? drbd_bm_free+0x2c/0x50 [drbd]
> <4>[4738.938366] kfree+0x2ca/0x370
> <4>[4738.938652] drbd_bm_free+0x2c/0x50 [drbd]
> <4>[4738.938946] drbd_cleanup_device+0x28/0x50 [drbd]
> <4>[4738.939246] adm_detach+0x21c/0x410 [drbd]
> <4>[4738.939544] ? __pfx_autoremove_wake_function+0x10/0x10
> <4>[4738.939822] drbd_adm_down+0x25c/0x460 [drbd]
> <4>[4738.940117] genl_family_rcv_msg_doit+0xf7/0x160
> <4>[4738.940396] genl_family_rcv_msg+0x184/0x250
> <4>[4738.940669] ? __pfx_drbd_adm_down+0x10/0x10 [drbd]
> <4>[4738.940961] genl_rcv_msg+0x4c/0xb0
> <4>[4738.941229] ? __pfx_genl_rcv_msg+0x10/0x10
> <4>[4738.941494] netlink_rcv_skb+0x5a/0x110
> <4>[4738.941756] genl_rcv+0x28/0x50
> <4>[4738.942018] netlink_unicast+0x289/0x3d0
> <4>[4738.942274] netlink_sendmsg+0x214/0x470
> <4>[4738.942529] sock_write_iter+0x18e/0x1a0
> <4>[4738.942783] vfs_write+0x3d2/0x470
> <4>[4738.943032] ksys_write+0xc9/0x100
> <4>[4738.943281] __x64_sys_write+0x19/0x30
> <4>[4738.943520] x64_sys_call+0x7e/0x25a0
> <4>[4738.943763] do_syscall_64+0x7f/0x180
> <4>[4738.944001] ? xen_set_pte+0x1f/0x80
> <4>[4738.944237] ? set_ptes.isra.0+0x21/0xa0
> <4>[4738.944467] ? _raw_spin_unlock+0xe/0x40
> <4>[4738.944699] ? do_anonymous_page+0x1a3/0x430
> <4>[4738.944968] ? handle_pte_fault+0x1cb/0x1d0
> <4>[4738.945193] ? __handle_mm_fault+0x654/0x790
> <4>[4738.945415] ? __count_memcg_events+0x6b/0x120
> <4>[4738.945630] ? count_memcg_events.constprop.0+0x34/0x50
> <4>[4738.945845] ? handle_mm_fault+0xad/0x380
> <4>[4738.946055] ? arch_exit_to_user_mode_prepare.isra.0+0x1a/0xe0
> <4>[4738.946263] ? irqentry_exit_to_user_mode+0x38/0x1e0
> <4>[4738.946471] ? irqentry_exit+0x43/0x50
> <4>[4738.946666] ? clear_bhb_loop+0x30/0x80
> <4>[4738.946852] ? clear_bhb_loop+0x30/0x80
> <4>[4738.947032] ? clear_bhb_loop+0x30/0x80
> <4>[4738.947206] entry_SYSCALL_64_after_hwframe+0x78/0x80
> <4>[4738.947386] RIP: 0033:0x703c470ee5a4
> <4>[4738.947574] Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d a5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
> <4>[4738.947949] RSP: 002b:00007ffe0bc2c268 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
> <4>[4738.948143] RAX: ffffffffffffffda RBX: 00005dd44b305e10 RCX: 0000703c470ee5a4
> <4>[4738.948334] RDX: 0000000000000050 RSI: 00005dd44b305e10 RDI: 0000000000000003
> <4>[4738.948523] RBP: 00007ffe0bc2c2a0 R08: 0000000000000000 R09: 00000000ffffffff
> <4>[4738.948710] R10: 00005dd4476377ee R11: 0000000000000202 R12: 0000000000000050
> <4>[4738.948899] R13: 0000000000000003 R14: 0000000000000050 R15: 00005dd447637099
> <4>[4738.949130] </TASK>
> <4>[4738.949315] Modules linked in: tls nls_iso8859_1 cls_cgroup sch_htb uas usb_storage drbd_transport_tcp(OE) drbd(OE) lru_cache bridge stp llc dummy cmdlinepart spi_nor mtd wmi_bmof dell_smbios mei_me dell_wmi_descriptor mgag200 i2c_algo_bit tg3 mei i2c_i801 spi_intel_pci lpc_ich i2c_smbus spi_intel ipmi_ssif acpi_power_meter intel_pch_thermal mac_hid acpi_ipmi ipmi_si xt_owner ipmi_devintf ipmi_msghandler xt_multiport xt_hl xt_tcpudp xt_conntrack nft_log xt_NFLOG nft_compat dell_rbu nft_chain_nat nf_nat nf_tables dcdbas nfnetlink_log cfg80211 binfmt_misc sch_fq_codel xen_pciback xen_netback xen_blkback nvme_fabrics nvme_keyring nvme_core nvme_auth xen_gntalloc xen_gntdev xen_evtchn xenfs nfnetlink dmi_sysfs ip_tables x_tables autofs4 raid10 raid0 xen_privcmd usbhid hid_generic hid zstd zram zfs(POE) spl(OE) nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 aufs raid1 dm_raid raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c megaraid_sas ahci xhci_pci efi_pstore xhci_pci_renesas libahci
> <4>[4738.949387] wmi
> <4>[4738.951729] ---[end trace 0000000000000000]---
> 
> ```