Bug 2484477 (CVE-2026-46259) - CVE-2026-46259 kernel: procfs: fix missing RCU protection when reading real_parent in do_task_stat()
Summary: CVE-2026-46259 kernel: procfs: fix missing RCU protection when reading real_p...
Keywords:
Status: NEW
Alias: CVE-2026-46259
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-06-03 18:03 UTC by OSIDB Bzimport
Modified: 2026-10-30 07:34 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2026:36018 0 None None None 2026-07-06 19:57:21 UTC
Red Hat Product Errata RHSA-2026:36348 0 None None None 2026-07-07 19:25:48 UTC
Red Hat Product Errata RHSA-2026:36349 0 None None None 2026-07-07 19:40:37 UTC
Red Hat Product Errata RHSA-2026:36541 0 None None None 2026-07-08 05:05:04 UTC
Red Hat Product Errata RHSA-2026:91489 0 None None None 2026-10-28 01:09:58 UTC
Red Hat Product Errata RHSA-2026:91585 0 None None None 2026-10-28 07:07:11 UTC
Red Hat Product Errata RHSA-2026:92997 0 None None None 2026-10-30 07:34:49 UTC

Description OSIDB Bzimport 2026-06-03 18:03:23 UTC 
In the Linux kernel, the following vulnerability has been resolved:

procfs: fix missing RCU protection when reading real_parent in do_task_stat()

When reading /proc/[pid]/stat, do_task_stat() accesses task->real_parent
without proper RCU protection, which leads to:

  cpu 0                               cpu 1
  -----                               -----
  do_task_stat
    var = task->real_parent
                                      release_task
                                        call_rcu(delayed_put_task_struct)
    task_tgid_nr_ns(var)
      rcu_read_lock   <--- Too late to protect task->real_parent!
      task_pid_ptr    <--- UAF!
      rcu_read_unlock

This patch uses task_ppid_nr_ns() instead of task_tgid_nr_ns() to add
proper RCU protection for accessing task->real_parent.
Comment 1 Keith Grant 2026-06-03 18:52:30 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026060336-CVE-2026-46259-6c94@gregkh/T
Comment 3 errata-xmlrpc 2026-07-06 19:57:20 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:36018 https://access.redhat.com/errata/RHSA-2026:36018
Comment 4 errata-xmlrpc 2026-07-07 19:25:47 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:36348 https://access.redhat.com/errata/RHSA-2026:36348
Comment 5 errata-xmlrpc 2026-07-07 19:40:36 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:36349 https://access.redhat.com/errata/RHSA-2026:36349
Comment 6 errata-xmlrpc 2026-07-08 05:05:03 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:36541 https://access.redhat.com/errata/RHSA-2026:36541
Comment 9 Jon Orris 2026-10-28 01:09:57 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

Via RHSA-2026:91489 https://access.redhat.com/errata/RHSA-2026:91489
Comment 10 Jon Orris 2026-10-28 07:07:10 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

Via RHSA-2026:91585 https://access.redhat.com/errata/RHSA-2026:91585
Comment 11 Jon Orris 2026-10-30 07:34:48 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.8 Telecommunications Update Service

Via RHSA-2026:92997 https://access.redhat.com/errata/RHSA-2026:92997
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