RHSA-2025:15035 - Security Advisory

Topic

An update for kernel is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: padata: fix UAF in padata_reorder (CVE-2025-21727)
• kernel: can: peak_usb: fix use after free bugs (CVE-2021-47670)
• kernel: net_sched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc (CVE-2025-37890)
• kernel: net_sched: hfsc: Address reentrant enqueue adding class to eltree twice (CVE-2025-38001)
• kernel: sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue() (CVE-2025-38000)
• kernel: crypto: algif_hash - fix double free in hash_accept (CVE-2025-38079)
• kernel: ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead (CVE-2022-49977)
• kernel: sch_hfsc: make hfsc_qlen_notify() idempotent (CVE-2025-38177)
• kernel: Bluetooth: hci_core: Fix use-after-free in vhci_flush() (CVE-2025-38250)
• kernel: net/sched: Always pass notifications when child class becomes empty (CVE-2025-38350)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Update Support Extension 8.4 x86_64
• Red Hat Enterprise Linux Server - AUS 8.4 x86_64

Fixes

• BZ - 2348516 - CVE-2025-21727 kernel: padata: fix UAF in padata_reorder
• BZ - 2360786 - CVE-2021-47670 kernel: can: peak_usb: fix use after free bugs
• BZ - 2366848 - CVE-2025-37890 kernel: net_sched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc
• BZ - 2370776 - CVE-2025-38001 kernel: net_sched: hfsc: Address reentrant enqueue adding class to eltree twice
• BZ - 2370786 - CVE-2025-38000 kernel: sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue()
• BZ - 2373383 - CVE-2025-38079 kernel: crypto: algif_hash - fix double free in hash_accept
• BZ - 2373574 - CVE-2022-49977 kernel: ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead
• BZ - 2376354 - CVE-2025-38177 kernel: sch_hfsc: make hfsc_qlen_notify() idempotent
• BZ - 2378982 - CVE-2025-38250 kernel: Bluetooth: hci_core: Fix use-after-free in vhci_flush()
• BZ - 2382054 - CVE-2025-38350 kernel: net/sched: Always pass notifications when child class becomes empty

CVEs

• CVE-2021-47670
• CVE-2022-49977
• CVE-2025-21727
• CVE-2025-37890
• CVE-2025-38000
• CVE-2025-38001
• CVE-2025-38079
• CVE-2025-38177
• CVE-2025-38250
• CVE-2025-38350
• CVE-2025-38684

References

• https://access.redhat.com/security/updates/classification/#important