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Augusto Caringi bdb8764f6f Merge: CVE-2025-21919: sched/fair: Fix potential memory corruption in child_cfs_rq_on_list
MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/6799

JIRA: https://issues.redhat.com/browse/RHEL-88083
CVE: CVE-2025-21919

```
commit 3b4035ddbfc8e4521f85569998a7569668cccf51
Author: Zecheng Li <zecheng@google.com>
Date:   Tue Mar 4 21:40:31 2025 +0000

    sched/fair: Fix potential memory corruption in child_cfs_rq_on_list

    child_cfs_rq_on_list attempts to convert a 'prev' pointer to a cfs_rq.
    This 'prev' pointer can originate from struct rq's leaf_cfs_rq_list,
    making the conversion invalid and potentially leading to memory
    corruption. Depending on the relative positions of leaf_cfs_rq_list and
    the task group (tg) pointer within the struct, this can cause a memory
    fault or access garbage data.

    The issue arises in list_add_leaf_cfs_rq, where both
    cfs_rq->leaf_cfs_rq_list and rq->leaf_cfs_rq_list are added to the same
    leaf list. Also, rq->tmp_alone_branch can be set to rq->leaf_cfs_rq_list.

    This adds a check `if (prev == &rq->leaf_cfs_rq_list)` after the main
    conditional in child_cfs_rq_on_list. This ensures that the container_of
    operation will convert a correct cfs_rq struct.

    This check is sufficient because only cfs_rqs on the same CPU are added
    to the list, so verifying the 'prev' pointer against the current rq's list
    head is enough.

    Fixes a potential memory corruption issue that due to current struct
    layout might not be manifesting as a crash but could lead to unpredictable
    behavior when the layout changes.

    Fixes: fdaba61ef8 ("sched/fair: Ensure that the CFS parent is added after unthrottling")
    Signed-off-by: Zecheng Li <zecheng@google.com>
    Reviewed-and-tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
    Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
    Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
    Link: https://lore.kernel.org/r/20250304214031.2882646-1-zecheng@google.com```

Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>

---

<small>Created 2025-04-29 13:27 UTC by backporter - [KWF FAQ](https://red.ht/kernel_workflow_doc) - [Slack #team-kernel-workflow](https://redhat-internal.slack.com/archives/C04LRUPMJQ5) - [Source](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/webhook/utils/backporter.py) - [Documentation](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/docs/README.backporter.md) - [Report an issue](https://issues.redhat.com/secure/CreateIssueDetails!init.jspa?pid=12334433&issuetype=1&priority=4&summary=backporter+webhook+issue&components=kernel-workflow+/+backporter)</small>

Approved-by: Phil Auld <pauld@redhat.com>
Approved-by: Xiubo Li <xiubli@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Augusto Caringi <acaringi@redhat.com>
2025-07-21 18:52:54 -03:00
Documentation Merge: FOP_ flags: lockd is not sending NLM_GRANTED messages 2025-07-21 18:52:52 -03:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2025-06-18 10:35:27 -03:00
arch Merge: FOP_ flags: lockd is not sending NLM_GRANTED messages 2025-07-21 18:52:52 -03:00
block Merge: FOP_ flags: lockd is not sending NLM_GRANTED messages 2025-07-21 18:52:52 -03:00
certs
crypto crypto: algif_hash - fix double free in hash_accept 2025-07-08 05:09:28 +00:00
drivers Merge: FOP_ flags: lockd is not sending NLM_GRANTED messages 2025-07-21 18:52:52 -03:00
fs Merge: FOP_ flags: lockd is not sending NLM_GRANTED messages 2025-07-21 18:52:52 -03:00
include Merge: FOP_ flags: lockd is not sending NLM_GRANTED messages 2025-07-21 18:52:52 -03:00
init
io_uring fs: claw back a few FMODE_* bits 2025-07-11 07:21:34 -04:00
ipc
kernel Merge: CVE-2025-21919: sched/fair: Fix potential memory corruption in child_cfs_rq_on_list 2025-07-21 18:52:54 -03:00
lib Merge: lib/group_cpus: fix NULL pointer dereference from group_cpus_evenly() 2025-07-11 11:46:28 -03:00
mm Merge: FOP_ flags: lockd is not sending NLM_GRANTED messages 2025-07-21 18:52:52 -03:00
net Merge: HyperV rebase to kernel 6.16-rc1 2025-07-15 15:53:50 -03:00
redhat Merge: arm64: Lock down the kernel if booted in secure boot mode 2025-07-21 18:52:45 -03:00
samples
scripts Merge: USB/TBT code rebase of supported drivers to upstream v6.14 2025-07-03 12:52:01 -03:00
security Merge: Update overlayfs to v6.7 2025-06-26 10:58:50 -03:00
sound ASoC: SOF: Intel: hda: do not use missing devm_kmalloc_array() 2025-06-13 20:11:54 +02:00
tools Merge: FOP_ flags: lockd is not sending NLM_GRANTED messages 2025-07-21 18:52:52 -03:00
usr
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MAINTAINERS Merge: HyperV rebase to kernel 6.16-rc1 2025-07-15 15:53:50 -03:00
Makefile Merge: USB/TBT code rebase of supported drivers to upstream v6.14 2025-07-03 12:52:01 -03:00
Makefile.rhelver [redhat] kernel-5.14.0-600.el9 2025-07-15 15:56:25 -03:00
README
makefile

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.