CVE-2025-39956

CVE-2025-39956 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: igc: don't fail igc_probe() on LED setup error When igc_led_setup() fails, igc_probe() fails and triggers kernel panic in free_netdev() since unregister_netdev() is not called. [1] This behavior can be tested using fault-injection framework, especially the failslab feature. [2] Since LED support is not mandatory, treat LED setup failures as non-fatal and continue probe with a warning message, consequently avoiding the kernel panic. [1] kernel BUG at net/core/dev.c:12047! Oops: invalid opcode: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 937 Comm: repro-igc-led-e Not tainted 6.17.0-rc4-enjuk-tnguy-00865-gc4940196ab02 #64 PREEMPT(voluntary) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:free_netdev+0x278/0x2b0 [...] Call Trace: <TASK> igc_probe+0x370/0x910 local_pci_probe+0x3a/0x80 pci_device_probe+0xd1/0x200 [...] [2] #!/bin/bash -ex FAILSLAB_PATH=/sys/kernel/debug/failslab/ DEVICE=0000:00:05.0 START_ADDR=$(grep " igc_led_setup" /proc/kallsyms \ | awk '{printf("0x%s", $1)}') END_ADDR=$(printf "0x%x" $((START_ADDR + 0x100))) echo $START_ADDR > $FAILSLAB_PATH/require-start echo $END_ADDR > $FAILSLAB_PATH/require-end echo 1 > $FAILSLAB_PATH/times echo 100 > $FAILSLAB_PATH/probability echo N > $FAILSLAB_PATH/ignore-gfp-wait echo $DEVICE > /sys/bus/pci/drivers/igc/bind

Frequently asked questions

What is CVE-2025-39956?
In the Linux kernel, the following vulnerability has been resolved: igc: don't fail igc_probe() on LED setup error When igc_led_setup() fails, igc_probe() fails and triggers kernel panic in free_netdev() since unregister_netdev() is not called. [1] This behavior can be tested using fault-injection framework, especially the failslab feature. [2] Since LED support is not mandatory, treat LED setup failures as non-fatal and continue probe with a warning message, consequently avoiding the kernel panic. [1] kernel BUG at net/core/dev.c:12047! Oops: invalid opcode: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 937 Comm: repro-igc-led-e Not tainted 6.17.0-rc4-enjuk-tnguy-00865-gc4940196ab02 #64 PREEMPT(voluntary) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:free_netdev+0x278/0x2b0 [...] Call Trace: <TASK> igc_probe+0x370/0x910 local_pci_probe+0x3a/0x80 pci_device_probe+0xd1/0x200 [...] [2] #!/bin/bash -ex FAILSLAB_PATH=/sys/kernel/debug/failslab/ DEVICE=0000:00:05.0 START_ADDR=$(grep " igc_led_setup" /proc/kallsyms \ | awk '{printf("0x%s", $1)}') END_ADDR=$(printf "0x%x" $((START_ADDR + 0x100))) echo $START_ADDR > $FAILSLAB_PATH/require-start echo $END_ADDR > $FAILSLAB_PATH/require-end echo 1 > $FAILSLAB_PATH/times echo 100 > $FAILSLAB_PATH/probability echo N > $FAILSLAB_PATH/ignore-gfp-wait echo $DEVICE > /sys/bus/pci/drivers/igc/bind
How severe is CVE-2025-39956?
CVE-2025-39956 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-39956 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-39956?
CVE-2025-39956 primarily affects Linux Linux Kernel. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-39956?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-39956 have an EU (EUVD) identifier?
Yes. CVE-2025-39956 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-33327.
When was CVE-2025-39956 published?
CVE-2025-39956 was published on 2025-10-09 and last updated on 2026-06-17.

References

Affected products (7)

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