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CVE-2025-37915

HIGHCVSS 7/10EPSS 0.17%

Last modified

CVE-2025-37915 is a high-severity vulnerability rated 7/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: net_sched: drr: Fix double list add in class with netem as child qdisc As described in Gerrard's report [1], there are use cases where a netem child qdisc will make the parent qdisc's enqueue callback reentrant. In the case of drr, there won't be a UAF, but the code will add the same classifier to the list twice, which will cause memory corruption. In addition to checking for qlen being zero, this patch checks whether the class was already added to the active_list (cl_is_active) before adding to the list to cover for the reentrant case. [1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/. EPSS estimates a 0.17% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: net_sched: drr: Fix double list add in class with netem as child qdisc As described in Gerrard's report [1], there are use cases where a netem child qdisc will make the parent qdisc's enqueue callback reentrant. In the case of drr, there won't be a UAF, but the code will add the same classifier to the list twice, which will cause memory corruption. In addition to checking for qlen being zero, this patch checks whether the class was already added to the active_list (cl_is_active) before adding to the list to cover for the reentrant case. [1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/

Metrics

CVSS 3.1
7/10

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.17%

6.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 5.0.1, < 5.4.294—
LinuxLinux Kernel>= 5.5, < 5.10.238—
LinuxLinux Kernel>= 5.11, < 5.15.182—
LinuxLinux Kernel>= 5.16, < 6.1.138—
LinuxLinux Kernel>= 6.2, < 6.6.90—
LinuxLinux Kernel>= 6.7, < 6.12.28—
LinuxLinux Kernel>= 6.13, < 6.14.6—
LinuxLinux Kernel5.0—
LinuxLinux Kernel6.15Rc1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2025-37915?
In the Linux kernel, the following vulnerability has been resolved: net_sched: drr: Fix double list add in class with netem as child qdisc As described in Gerrard's report [1], there are use cases where a netem child qdisc will make the parent qdisc's enqueue callback reentrant. In the case of drr, there won't be a UAF, but the code will add the same classifier to the list twice, which will cause memory corruption. In addition to checking for qlen being zero, this patch checks whether the class was already added to the active_list (cl_is_active) before adding to the list to cover for the reentrant case. [1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/
How severe is CVE-2025-37915?
CVE-2025-37915 has a CVSS score of 7/10 (HIGH severity). The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.
How do I fix CVE-2025-37915?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST