CVE-2025-38651

CVE-2025-38651 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: landlock: Fix warning from KUnit tests get_id_range() expects a positive value as first argument but get_random_u8() can return 0. Fix this by clamping it. Validated by running the test in a for loop for 1000 times. Note that MAX() is wrong as it is only supposed to be used for constants, but max() is good here. [..] ok 9 test_range2_rand1 [..] ok 10 test_range2_rand2 [..] ok 11 test_range2_rand15 [..] ------------[ cut here ]------------ [..] WARNING: CPU: 6 PID: 104 at security/landlock/id.c:99 test_range2_rand16 (security/landlock/id.c:99 (discriminator 1) security/landlock/id.c:234 (discriminator 1)) [..] Modules linked in: [..] CPU: 6 UID: 0 PID: 104 Comm: kunit_try_catch Tainted: G N 6.16.0-rc1-dev-00001-g314a2f98b65f #1 PREEMPT(undef) [..] Tainted: [N]=TEST [..] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [..] RIP: 0010:test_range2_rand16 (security/landlock/id.c:99 (discriminator 1) security/landlock/id.c:234 (discriminator 1)) [..] Code: 49 c7 c0 10 70 30 82 4c 89 ff 48 c7 c6 a0 63 1e 83 49 c7 45 a0 e0 63 1e 83 e8 3f 95 17 00 e9 1f ff ff ff 0f 0b e9 df fd ff ff <0f> 0b ba 01 00 00 00 e9 68 fe ff ff 49 89 45 a8 49 8d 4d a0 45 31 [..] RSP: 0000:ffff888104eb7c78 EFLAGS: 00010246 [..] RAX: 0000000000000000 RBX: 000000000870822c RCX: 0000000000000000 ^^^^^^^^^^^^^^^^ [..] [..] Call Trace: [..] [..] ---[ end trace 0000000000000000 ]--- [..] ok 12 test_range2_rand16 [..] # landlock_id: pass:12 fail:0 skip:0 total:12 [..] # Totals: pass:12 fail:0 skip:0 total:12 [..] ok 1 landlock_id [mic: Minor cosmetic improvements]

Frequently asked questions

What is CVE-2025-38651?
In the Linux kernel, the following vulnerability has been resolved: landlock: Fix warning from KUnit tests get_id_range() expects a positive value as first argument but get_random_u8() can return 0. Fix this by clamping it. Validated by running the test in a for loop for 1000 times. Note that MAX() is wrong as it is only supposed to be used for constants, but max() is good here. [..] ok 9 test_range2_rand1 [..] ok 10 test_range2_rand2 [..] ok 11 test_range2_rand15 [..] ------------[ cut here ]------------ [..] WARNING: CPU: 6 PID: 104 at security/landlock/id.c:99 test_range2_rand16 (security/landlock/id.c:99 (discriminator 1) security/landlock/id.c:234 (discriminator 1)) [..] Modules linked in: [..] CPU: 6 UID: 0 PID: 104 Comm: kunit_try_catch Tainted: G N 6.16.0-rc1-dev-00001-g314a2f98b65f #1 PREEMPT(undef) [..] Tainted: [N]=TEST [..] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [..] RIP: 0010:test_range2_rand16 (security/landlock/id.c:99 (discriminator 1) security/landlock/id.c:234 (discriminator 1)) [..] Code: 49 c7 c0 10 70 30 82 4c 89 ff 48 c7 c6 a0 63 1e 83 49 c7 45 a0 e0 63 1e 83 e8 3f 95 17 00 e9 1f ff ff ff 0f 0b e9 df fd ff ff <0f> 0b ba 01 00 00 00 e9 68 fe ff ff 49 89 45 a8 49 8d 4d a0 45 31 [..] RSP: 0000:ffff888104eb7c78 EFLAGS: 00010246 [..] RAX: 0000000000000000 RBX: 000000000870822c RCX: 0000000000000000 ^^^^^^^^^^^^^^^^ [..] [..] Call Trace: [..] [..] ---[ end trace 0000000000000000 ]--- [..] ok 12 test_range2_rand16 [..] # landlock_id: pass:12 fail:0 skip:0 total:12 [..] # Totals: pass:12 fail:0 skip:0 total:12 [..] ok 1 landlock_id [mic: Minor cosmetic improvements]
How severe is CVE-2025-38651?
CVE-2025-38651 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-2025-38651 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-38651?
CVE-2025-38651 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-38651?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-38651 have an EU (EUVD) identifier?
Yes. CVE-2025-38651 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-25551.
When was CVE-2025-38651 published?
CVE-2025-38651 was published on 2025-08-22 and last updated on 2026-06-17.

References

Affected products (1)

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