Bug 114871 - bcache: "unable to handle kernel NULL pointer dereference" when trying to add a md caching device
Summary: bcache: "unable to handle kernel NULL pointer dereference" when trying to add...
Status: NEW
Alias: None
Product: IO/Storage
Classification: Unclassified
Component: Other (show other bugs)
Hardware: Intel Linux
: P1 normal
Assignee: Michael Lyle
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2016-03-18 11:17 UTC by Sebastian Roesner
Modified: 2020-02-15 17:17 UTC (History)
2 users (show)

See Also:
Kernel Version: 4.5.0
Subsystem:
Regression: Yes
Bisected commit-id:

Attachments
Traces and system information (3.44 KB, application/x-gzip)
2016-03-18 11:17 UTC, Sebastian Roesner 		Details
trace 1 (5.52 KB, application/octet-stream)
2016-03-18 11:18 UTC, Sebastian Roesner 		Details
trace 2 (5.72 KB, text/plain)
2016-03-18 11:19 UTC, Sebastian Roesner 		Details
lsblk (2.20 KB, text/plain)
2016-03-18 11:19 UTC, Sebastian Roesner 		Details
bcache-super-show (1.07 KB, text/plain)
2016-03-18 11:20 UTC, Sebastian Roesner 		Details
Add an attachment (proposed patch, testcase, etc.)

Description Sebastian Roesner 2016-03-18 11:17:42 UTC 
Created attachment 209731 [details]
Traces and system information

I use bcache with 2 raid devices as the underlaying block devices. With 4.5.0 I got "BUG: unable to handle kernel NULL pointer dereference at 0000000000000028" when trying to add the cache device:

echo /dev/md2 > /sys/fs/bcache/register

With kernel 3.19 that worked fine, since it's a productive system I didn't try any other kernel versions in between.
Comment 1 Sebastian Roesner 2016-03-18 11:18:53 UTC 
Created attachment 209741 [details]
trace 1
Comment 2 Sebastian Roesner 2016-03-18 11:19:18 UTC 
Created attachment 209751 [details]
trace 2
Comment 3 Sebastian Roesner 2016-03-18 11:19:51 UTC 
Created attachment 209761 [details]
lsblk
Comment 4 Sebastian Roesner 2016-03-18 11:20:19 UTC 
Created attachment 209771 [details]
bcache-super-show
Comment 5 Coly Li 2020-02-15 17:17:19 UTC 
Does this problem still show up in Linux v5.5 or v5.6-rc ?

Thanks.

Coly Li
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