CVE-2026-74284

A flaw was found in the Linux kernel's Hierarchical Fair Service Curve HFSC queueing discipline schhfsc. When a child qdisc drops its last packets, the updatevf function can be called twice for the same class, causing it to be marked passive multiple times. This double transition can lead to a...

kernel: net_sched: hfsc: Fix a UAF vulnerability in class handling

In the Linux kernel, the following vulnerability has been resolved: netsched: hfsc: Fix a UAF vulnerability in class handling This patch fixes a Use-After-Free vulnerability in the HFSC qdisc class handling. The issue occurs due to a time-of-check/time-of-use condition in hfscchangeclass when...

Astra Linux – Vulnerability found in Linux 6.1, Linux 6.12

In the Linux kernel, the following vulnerability has been resolved: netsched: hfsc: Fixed a UAF vulnerability in class handling This patch addresses a Use-After-Free vulnerability in the HFSC qdisc class handling. The issue arises due to a time-of-check/time-of-use condition in hfscchangeclass,...

Astra Linux – Vulnerability found in Linux 6.1, Linux 6.12

In the Linux kernel, the following vulnerability has been resolved: netsched: hfsc: A UAF vulnerability has been fixed in classes where netem is a child qdisc. As described in Gerrard’s report 1, there is a UAF case when an hfsc class has a netem child qdisc. The core issue is that hfsc assumes...

CVE-2025-37890

In the Linux kernel, the following vulnerability has been resolved: netsched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc As described in Gerrard's report 1, we have a UAF case when an hfsc class has a netem child qdisc. The crux of the issue is that hfsc is assuming that...

DEBIAN-CVE-2025-37890

In the Linux kernel, the following vulnerability has been resolved: netsched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc As described in Gerrard's report 1, we have a UAF case when an hfsc class has a netem child qdisc. The crux of the issue is that hfsc is assuming that...

CVE-2025-37890 net_sched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc

In the Linux kernel, the following vulnerability has been resolved: netsched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc As described in Gerrard's report 1, we have a UAF case when an hfsc class has a netem child qdisc. The crux of the issue is that hfsc is assuming that...

CVE-2025-37890 net_sched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc

In the Linux kernel, the following vulnerability has been resolved: netsched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc As described in Gerrard's report 1, we have a UAF case when an hfsc class has a netem child qdisc. The crux of the issue is that hfsc is assuming that...

PT-2025-18776

Name of the Vulnerable Software and Affected Versions Linux kernel affected versions not specified Description A Use-After-Free vulnerability has been identified in the HFSC qdisc class handling of the Linux kernel. The issue arises from a time-of-check/time-of-use condition in hfsc change class...

kernel: net/sched: sch_hfsc UAF

A use-after-free flaw was found in the Linux kernel's net/sched: schhfsc HFSC qdisc traffic control component that can be exploited to achieve local privilege escalation. If a class with a link-sharing curve, for example, with the HFSCFSC flag set, has a parent without a link-sharing curve, then...

kernel: net/sched: sch_hfsc UAF

A use-after-free flaw was found in the Linux kernel's net/sched: schhfsc HFSC qdisc traffic control component that can be exploited to achieve local privilege escalation. If a class with a link-sharing curve, for example, with the HFSCFSC flag set, has a parent without a link-sharing curve, then...

kernel: net/sched: sch_hfsc UAF

A use-after-free flaw was found in the Linux kernel's net/sched: schhfsc HFSC qdisc traffic control component that can be exploited to achieve local privilege escalation. If a class with a link-sharing curve, for example, with the HFSCFSC flag set, has a parent without a link-sharing curve, then...

kernel: net/sched: sch_hfsc UAF

A use-after-free flaw was found in the Linux kernel's net/sched: schhfsc HFSC qdisc traffic control component that can be exploited to achieve local privilege escalation. If a class with a link-sharing curve, for example, with the HFSCFSC flag set, has a parent without a link-sharing curve, then...

kernel: net/sched: sch_hfsc UAF

A use-after-free flaw was found in the Linux kernel's net/sched: schhfsc HFSC qdisc traffic control component that can be exploited to achieve local privilege escalation. If a class with a link-sharing curve, for example, with the HFSCFSC flag set, has a parent without a link-sharing curve, then...

kernel: net/sched: sch_hfsc UAF

A use-after-free flaw was found in the Linux kernel's net/sched: schhfsc HFSC qdisc traffic control component that can be exploited to achieve local privilege escalation. If a class with a link-sharing curve, for example, with the HFSCFSC flag set, has a parent without a link-sharing curve, then...

kernel: net/sched: sch_hfsc UAF

A use-after-free flaw was found in the Linux kernel's net/sched: schhfsc HFSC qdisc traffic control component that can be exploited to achieve local privilege escalation. If a class with a link-sharing curve, for example, with the HFSCFSC flag set, has a parent without a link-sharing curve, then...

kernel: net/sched: sch_hfsc UAF

A use-after-free flaw was found in the Linux kernel's net/sched: schhfsc HFSC qdisc traffic control component that can be exploited to achieve local privilege escalation. If a class with a link-sharing curve, for example, with the HFSCFSC flag set, has a parent without a link-sharing curve, then...

kernel: net/sched: sch_hfsc UAF

A use-after-free flaw was found in the Linux kernel's net/sched: schhfsc HFSC qdisc traffic control component that can be exploited to achieve local privilege escalation. If a class with a link-sharing curve, for example, with the HFSCFSC flag set, has a parent without a link-sharing curve, then...

kernel: net/sched: sch_hfsc UAF

A use-after-free flaw was found in the Linux kernel's net/sched: schhfsc HFSC qdisc traffic control component that can be exploited to achieve local privilege escalation. If a class with a link-sharing curve, for example, with the HFSCFSC flag set, has a parent without a link-sharing curve, then...

kernel: net/sched: sch_hfsc UAF

A use-after-free flaw was found in the Linux kernel's net/sched: schhfsc HFSC qdisc traffic control component that can be exploited to achieve local privilege escalation. If a class with a link-sharing curve, for example, with the HFSCFSC flag set, has a parent without a link-sharing curve, then...