CVE-2025-38651
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-08-22

Last updated on: 2025-11-26

Assigner: kernel.org

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]
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Meta Information
Published
2025-08-22
Last Modified
2025-11-26
Generated
2026-05-07
AI Q&A
2025-08-22
EPSS Evaluated
2026-05-05
NVD
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
Helpful Resources
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CWE ID Description
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AI Powered Q&A
How can this vulnerability impact me? :

The vulnerability causes warnings during kernel unit testing due to improper handling of a zero value where a positive value was expected. While it does not describe a direct security exploit or system compromise, such warnings could indicate potential instability or unexpected behavior in the landlock security module if left unaddressed. Fixing this ensures more reliable and stable kernel behavior.


Can you explain this vulnerability to me?

This vulnerability is related to the Linux kernel's landlock security module. The issue was that the function get_id_range() expected a positive value as its first argument, but the function get_random_u8() could return 0, which is not positive. This mismatch caused warnings during KUnit tests. The fix involved clamping the value to ensure it is positive, preventing the warning and potential issues in the code execution.


How can this vulnerability be detected on my network or system? Can you suggest some commands?

This vulnerability is related to a warning in the Linux kernel's landlock security module during KUnit tests, specifically involving get_id_range() and get_random_u8(). Detection would involve checking kernel logs for warnings or errors related to landlock and the specific test_range2_rand16 warning. You can use the command 'dmesg | grep landlock' or 'journalctl -k | grep landlock' to look for such warnings in the kernel logs.


What immediate steps should I take to mitigate this vulnerability?

The vulnerability has been fixed by clamping the value returned by get_random_u8() to ensure it is positive as expected by get_id_range(). Immediate mitigation involves updating the Linux kernel to a version that includes this fix. There are no other specific mitigation steps mentioned.


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