Bug 624454

Summary:	Kernel panic while using PAX - size overflow detected in function ext4_mb_scan_aligned
Product:	Gentoo Linux	Reporter:	Stephen Shkardoon <ss23>
Component:	Hardened	Assignee:	The Gentoo Linux Hardened Team <hardened>
Status:	RESOLVED INVALID
Severity:	normal	CC:	tsmksubc
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---

Description Stephen Shkardoon 2017-07-10 14:00:27 UTC

I am using PAX with most options enabled, and I have been getting kernel panics over the past month and with a serial console attached I can see the error:
PAX: size overflow detected in function ext4_mb_scan_aligned fs/ext4/ext4.h:2110 cicus.1656_90 max, count: 213, decl: mb_find_extent; num: 2; context: fndecl;

I am running the latest version of hardened-sources, getting the panic with both stable and ~ (4.9.23 and 4.8.17-r2).

This piece of code looks related to running raid5/6 (which I am, and I am also running LVM and LUKS).
I don't have the ability to debug this myself, though it may be a similar situation to https://github.com/zfsonlinux/zfs/issues/2505.

I don't have any reproduction steps, as it seems to happen on an irregular basis, perhaps triggered most during disk writes, though that may be anecdote.

General setup:
x86_64 system
Multiple HDDs in RAID6, LUKS, LVM, ext4

Comment 1 Stephen Shkardoon 2017-07-10 14:01:55 UTC

That specific error is while running hardened-sources 4.9.23 (I don't have the serial output from 4.8.17-r2)

Comment 2 Stephen Shkardoon 2018-08-09 13:01:10 UTC

No longer really required with the changes to hardened.