Bug 1941762 (CVE-2021-28950) - CVE-2021-28950 kernel: fuse: stall on CPU can occur because a retry loop continually finds the same bad inode
Summary: CVE-2021-28950 kernel: fuse: stall on CPU can occur because a retry loop cont...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2021-28950
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1946535 1941763 1944483 1944484 1944489 1949873 2015840 2015841
Blocks: 1941764
TreeView+ depends on / blocked
 
Reported: 2021-03-22 18:10 UTC by Guilherme de Almeida Suckevicz
Modified: 2022-04-17 21:14 UTC (History)
45 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
A denial of service in the kernel side of the FUSE functionality can allow a local system to create a denial of service.
Clone Of:
Environment:
Last Closed: 2021-11-15 11:31:29 UTC
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2021:4140 0 None None None 2021-11-09 17:21:56 UTC
Red Hat Product Errata RHSA-2021:4356 0 None None None 2021-11-09 18:24:17 UTC
Red Hat Product Errata RHSA-2021:4648 0 None None None 2021-11-15 10:13:12 UTC
Red Hat Product Errata RHSA-2021:4650 0 None None None 2021-11-15 11:06:09 UTC

Description Guilherme de Almeida Suckevicz 2021-03-22 18:10:47 UTC 
An issue was discovered in fs/fuse/fuse_i.h in the Linux kernel before 5.11.8. A "stall on CPU" can occur because a retry loop continually finds the same bad inode.

Reference and upstream patch:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=775c5033a0d164622d9d10dd0f0a5531639ed3ed
Comment 1 Guilherme de Almeida Suckevicz 2021-03-22 18:11:34 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1941763]
Comment 5 Wade Mealing 2021-03-30 02:18:11 UTC 
Mitigation:


As the FUSE module will be auto-loaded when required, its use can be disabled  by preventing the module from loading with the following instructions:

# echo "install fuse /bin/true" >> /etc/modprobe.d/disable-fuse.conf

The system will need to be restarted if the FUSE modules are loaded. In most circumstances, the CIFS kernel modules will be unable to be unloaded while the FUSE filesystems are in  use.

If the system requires this module to work correctly, this mitigation may not be suitable.

If you need further assistance, see KCS article https://access.redhat.com/solutions/41278 or contact Red Hat Global Support Services.
Comment 24 errata-xmlrpc 2021-11-09 17:21:54 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:4140 https://access.redhat.com/errata/RHSA-2021:4140
Comment 25 errata-xmlrpc 2021-11-09 18:24:14 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:4356 https://access.redhat.com/errata/RHSA-2021:4356
Comment 26 errata-xmlrpc 2021-11-15 10:13:09 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Extended Update Support

Via RHSA-2021:4648 https://access.redhat.com/errata/RHSA-2021:4648
Comment 27 errata-xmlrpc 2021-11-15 11:06:06 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Extended Update Support

Via RHSA-2021:4650 https://access.redhat.com/errata/RHSA-2021:4650
Comment 28 Product Security DevOps Team 2021-11-15 11:31:25 UTC 
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2021-28950
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