Bug 2324548 (CVE-2024-50191)

Summary:	CVE-2024-50191 kernel: ext4: don't set SB_RDONLY after filesystem errors
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	dfreiber, drow, jburrell, vkumar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2324700
Bug Blocks:

Description OSIDB Bzimport 2024-11-08 13:44:47 UTC

In the Linux kernel, the following vulnerability has been resolved:

ext4: don't set SB_RDONLY after filesystem errors

When the filesystem is mounted with errors=remount-ro, we were setting
SB_RDONLY flag to stop all filesystem modifications. We knew this misses
proper locking (sb->s_umount) and does not go through proper filesystem
remount procedure but it has been the way this worked since early ext2
days and it was good enough for catastrophic situation damage
mitigation. Recently, syzbot has found a way (see link) to trigger
warnings in filesystem freezing because the code got confused by
SB_RDONLY changing under its hands. Since these days we set
EXT4_FLAGS_SHUTDOWN on the superblock which is enough to stop all
filesystem modifications, modifying SB_RDONLY shouldn't be needed. So
stop doing that.

Comment 1 Robb Gatica 2024-11-08 15:42:07 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024110851-CVE-2024-50191-f31c@gregkh/T

Comment 2 errata-xmlrpc 2025-05-13 08:33:42 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2025:6966 https://access.redhat.com/errata/RHSA-2025:6966