bpf: Send signals asynchronously if !preemptible
Priority LOW 24Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 5 fixed, 3 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Send signals asynchronously if !preemptible BPF programs can execute in all kinds of contexts and when a program running in a non-preemptible context uses the bpf_send_signal() kfunc, it will cause issues because this kfunc can sleep. Change `irqs_disabled()` to `!preemptible()`.
Why it matters now
EPSS 0.00214 11th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.4.291, 5.6, 5.10.235 +6Red Hat: 1 advisoryRed Hat: 5 fixed, 3 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.4.33 to before 5.4.291; 5.5.18 to before 5.6 | 5.4.291, 5.6 | Patch available | CNA |
| Linux | Linux | 5.6 and later | 5.4.291, 5.10.235, 5.15.179, 6.1.129, 6.6.76, 6.12.13, 6.13.2, 6.14 | Patch available | CNA |
- Linux VendorLinux Affected 5.4.33 to before 5.4.291; 5.5.18 to before 5.6 Fixed in 5.4.291, 5.6 Patch available CNA
- Linux VendorLinux Affected 5.6 and later Fixed in 5.4.291, 5.10.235, 5.15.179, 6.1.129, 6.6.76, 6.12.13, 6.13.2, 6.14 Patch available CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.4.33 to before 5.4.291; 5.5.18 to before 5.6; 5.6.1 to before 5.10.235; 5.11 to before 5.15.179; 5.16 to before 6.1.129; 6.2 to before 6.6.76; 6.7 to before 6.12.13; 6.13 to before 6.13.2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.6:-:*:*:*:*:*:* | 5.6 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.4.33 to before 5.4.291; 5.5.18 to before 5.6; 5.6.1 to before 5.10.235; 5.11 to before 5.15.179; 5.16 to before 6.1.129; 6.2 to before 6.6.76; 6.7 to before 6.12.13; 6.13 to before 6.13.2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.6:-:*:*:*:*:*:* Versions 5.6 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.4.291, 5.6
- Fix · CNA Linux (Linux) Fixed in 5.4.291, 5.10.235, 5.15.179, 6.1.129, 6.6.76, 6.12.13, 6.13.2, 6.14
Red Hat 1 advisory
- RHSA-2025:20518 Released 2025-11-11 · Red Hat rating Moderatekernel security update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-611.5.1.el9_7, kernel-64k-debug-devel-matched-5.14.0-611.5.1.el9_7, kernel-64k-devel-5.14.0-611.5.1.el9_7 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-611.5.1.el9_7, kernel-64k-5.14.0-611.5.1.el9_7, kernel-64k-core-5.14.0-611.5.1.el9_7 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-611.5.1.el9_7, libperf-5.14.0-611.5.1.el9_7
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-611.5.1.el9_7, kernel-rt-64k-5.14.0-611.5.1.el9_7, kernel-rt-64k-core-5.14.0-611.5.1.el9_7 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-611.5.1.el9_7, kernel-rt-core-5.14.0-611.5.1.el9_7, kernel-rt-debug-5.14.0-611.5.1.el9_7 +9
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2025:20518 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2025:20518 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2025:20518 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2025:20518 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2025:20518 |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2025-21728
- 2026-10-03 Alias added: GHSA-f47w-fp34-vr9h
- 2026-10-29 Affected versions changed · Red Hat
References
Patch 8
- https://git.kernel.org/stable/c/feba1308bc5e8e04cee751d39fae8a9b407a9034
- https://git.kernel.org/stable/c/ce51eab2070e295d298f42a2f1db269cd1b56d55
- https://git.kernel.org/stable/c/e306eaaa3d78b462db5f5b11e0171f9d2b6ca3f4
- https://git.kernel.org/stable/c/be42a09fe898635b0093c0c8dac1bfabe225c240
- https://git.kernel.org/stable/c/eeef8e65041a031bd8a747a392c14b76a123a12c
- https://git.kernel.org/stable/c/78b97783496b454435639937db3303e900a24d3f
- https://git.kernel.org/stable/c/092fc76b7ab4163e008f9cde596a58dad2108260
- https://git.kernel.org/stable/c/87c544108b612512b254c8f79aa5c0a8546e2cc4
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2025-21728 · CVE Program
- CVE-2025-21728 · NVD
- FIRST EPSS
- GHSA-f47w-fp34-vr9h · GitHub Advisory Database · CC BY 4.0
- CVE-2025-21728 · Red Hat security data · CC BY 4.0
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