CVE-2025-38468
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2025-38468
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-38468.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2025-38468
- Downstream
- Published
- 2025-07-28T12:15:28Z
- Modified
- 2025-07-29T14:49:55.882880Z
- Summary
- [none]
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
net/sched: Return NULL when htblookupleaf encounters an empty rbtree
htblookupleaf has a BUG_ON that can trigger with the following:
tc qdisc del dev lo root tc qdisc add dev lo root handle 1: htb default 1 tc class add dev lo parent 1: classid 1:1 htb rate 64bit tc qdisc add dev lo parent 1:1 handle 2: netem tc qdisc add dev lo parent 2:1 handle 3: blackhole ping -I lo -c1 -W0.001 127.0.0.1
The root cause is the following:
- htbdequeue calls htbdequeue_tree which calls the dequeue handler on the selected leaf qdisc
- netem_dequeue calls enqueue on the child qdisc
- blackholeenqueue drops the packet and returns a value that is not just NETXMIT_SUCCESS
- Because of this, netemdequeue calls qdisctreereducebacklog, and since qlen is now 0, it calls htbqlennotify -> htbdeactivate -> htbdeactiviateprios -> htbremoveclassfromrow -> htbsaferberase
- As this is the only class in the selected hprio rbtree, _rbchangechild in _rberaseaugmented sets the rb_root pointer to NULL
- Because blackholedequeue returns NULL, netemdequeue returns NULL, which causes htbdequeuetree to call htblookupleaf with the same hprio rbtree, and fail the BUG_ON
The function graph for this scenario is shown here: 0) | htbenqueue() { 0) + 13.635 us | netemenqueue(); 0) 4.719 us | htbactivateprios(); 0) # 2249.199 us | } 0) | htbdequeue() { 0) 2.355 us | htblookupleaf(); 0) | netemdequeue() { 0) + 11.061 us | blackholeenqueue(); 0) | qdisctreereducebacklog() { 0) | qdisclookuprcu() { 0) 1.873 us | qdiscmatchfromroot(); 0) 6.292 us | } 0) 1.894 us | htbsearch(); 0) | htbqlennotify() { 0) 2.655 us | htbdeactivateprios(); 0) 6.933 us | } 0) + 25.227 us | } 0) 1.983 us | blackholedequeue(); 0) + 86.553 us | } 0) # 2932.761 us | qdiscwarnnonwc(); 0) | htblookupleaf() { 0) | BUGON();
The full original bug report can be seen here [1].
We can fix this just by returning NULL instead of the BUGON, as htbdequeuetree returns NULL when htblookup_leaf returns NULL.
[1] https://lore.kernel.org/netdev/pF5XOOIim0IuEfhI-SOxTgRvNoDwuux7UHKnE_Y5-zVd4wmGvNk2ceHjKb8ORnzw0cGwfmVu42g9dL7XyJLf1NEzaztboTWcm0Ogxuojoeo=@willsroot.io/
- References
-
- https://git.kernel.org/stable/c/0e1d5d9b5c5966e2e42e298670808590db5ed628
- https://git.kernel.org/stable/c/3691f84269a23f7edd263e9b6edbc27b7ae332f4
- https://git.kernel.org/stable/c/7ff2d83ecf2619060f30ecf9fad4f2a700fca344
- https://git.kernel.org/stable/c/890a5d423ef0a7bd13447ceaffad21189f557301
- https://git.kernel.org/stable/c/e5c480dc62a3025b8428d4818e722da30ad6804f
- https://security-tracker.debian.org/tracker/CVE-2025-38468
Affected packages
Debian:11 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affected
Affected versions
5.*
5.10.46-4
5.10.46-5
5.10.70-1~bpo10+1
5.10.70-1
5.10.84-1
5.10.92-1~bpo10+1
5.10.92-1
5.10.92-2
5.10.103-1~bpo10+1
5.10.103-1
5.10.106-1
5.10.113-1
5.10.120-1~bpo10+1
5.10.120-1
5.10.127-1
5.10.127-2~bpo10+1
5.10.127-2
5.10.136-1
5.10.140-1
5.10.148-1
5.10.149-1
5.10.149-2
5.10.158-1
5.10.158-2
5.10.162-1
5.10.178-1
5.10.178-2
5.10.178-3
5.10.179-1
5.10.179-2
5.10.179-3
5.10.179-4
5.10.179-5
5.10.191-1
5.10.197-1
5.10.205-1
5.10.205-2
5.10.209-1
5.10.209-2
5.10.216-1
5.10.218-1
5.10.221-1
5.10.223-1
5.10.226-1
5.10.234-1
5.10.237-1
5.13.9-1~exp1
5.13.9-1~exp2
5.13.12-1~exp1
5.14-1~exp1
5.14-1~exp2
5.14.1-1~exp1
5.14.2-1~exp1
5.14.3-1~exp1
5.14.6-1
5.14.6-2
5.14.6-3
5.14.9-1
5.14.9-2~bpo11+1
5.14.9-2
5.14.12-1
5.14.16-1
5.15-1~exp1
5.15.1-1~exp1
5.15.2-1~exp1
5.15.3-1
5.15.5-1
5.15.5-2~bpo11+1
5.15.5-2
5.15.15-1
5.15.15-2~bpo11+1
5.15.15-2
5.16~rc1-1~exp1
5.16~rc3-1~exp1
5.16~rc4-1~exp1
5.16~rc5-1~exp1
5.16~rc6-1~exp1
5.16~rc7-1~exp1
5.16~rc8-1~exp1
5.16.3-1~exp1
5.16.4-1~exp1
5.16.7-1
5.16.7-2
5.16.10-1
5.16.11-1~bpo11+1
5.16.11-1
5.16.12-1~bpo11+1
5.16.12-1
5.16.14-1
5.16.18-1
5.17~rc3-1~exp1
5.17~rc4-1~exp1
5.17~rc5-1~exp1
5.17~rc6-1~exp1
5.17~rc7-1~exp1
5.17~rc8-1~exp1
5.17.1-1~exp1
5.17.3-1
5.17.6-1
5.17.11-1
5.18-1~exp1
5.18.2-1~bpo11+1
5.18.2-1
5.18.5-1
5.18.14-1~bpo11+1
5.18.14-1
5.18.16-1~bpo11+1
5.18.16-1
5.19~rc4-1~exp1
5.19~rc6-1~exp1
5.19-1~exp1
5.19.6-1
5.19.11-1~bpo11+1
5.19.11-1
6.*
6.0~rc7-1~exp1
6.0-1~exp1
6.0.2-1
6.0.3-1~bpo11+1
6.0.3-1
6.0.5-1
6.0.6-1
6.0.6-2
6.0.7-1
6.0.8-1
6.0.10-1
6.0.10-2
6.0.12-1~bpo11+1
6.0.12-1
6.0.12-1+alpha
6.1~rc3-1~exp1
6.1~rc5-1~exp1
6.1~rc6-1~exp1
6.1~rc7-1~exp1
6.1~rc8-1~exp1
6.1.1-1~exp1
6.1.1-1~exp2
6.1.2-1~exp1
6.1.4-1
6.1.7-1
6.1.8-1
6.1.8-1+sh4
6.1.11-1
6.1.12-1~bpo11+1
6.1.12-1
6.1.15-1~bpo11+1
6.1.15-1
6.1.20-1~bpo11+1
6.1.20-1
6.1.20-2~bpo11+1
6.1.20-2
6.1.25-1
6.1.27-1~bpo11+1
6.1.27-1
6.1.37-1
6.1.38-1
6.1.38-2~bpo11+1
6.1.38-2
6.1.38-3
6.1.38-4~bpo11+1
6.1.38-4
6.1.52-1
6.1.55-1~bpo11+1
6.1.55-1
6.1.64-1
6.1.66-1
6.1.67-1
6.1.69-1~bpo11+1
6.1.69-1
6.1.76-1~bpo11+1
6.1.76-1
6.1.82-1
6.1.85-1
6.1.90-1~bpo11+1
6.1.90-1
6.1.94-1~bpo11+1
6.1.94-1
6.1.98-1
6.1.99-1
6.1.106-1
6.1.106-2
6.1.106-3
6.1.112-1
6.1.115-1
6.1.119-1
6.1.123-1
6.1.124-1
6.1.128-1
6.1.129-1
6.1.133-1
6.1.135-1
6.1.137-1
6.1.139-1
6.1.140-1
6.3.1-1~exp1
6.3.2-1~exp1
6.3.4-1~exp1
6.3.5-1~exp1
6.3.7-1~bpo12+1
6.3.7-1
6.3.11-1
6.4~rc6-1~exp1
6.4~rc7-1~exp1
6.4.1-1~exp1
6.4.4-1~bpo12+1
6.4.4-1
6.4.4-2
6.4.4-3~bpo12+1
6.4.4-3
6.4.11-1
6.4.13-1
6.5~rc4-1~exp1
6.5~rc6-1~exp1
6.5~rc7-1~exp1
6.5.1-1~exp1
6.5.3-1~bpo12+1
6.5.3-1
6.5.6-1
6.5.8-1
6.5.10-1~bpo12+1
6.5.10-1
6.5.13-1
6.6.3-1~exp1
6.6.4-1~exp1
6.6.7-1~exp1
6.6.8-1
6.6.9-1
6.6.11-1
6.6.13-1~bpo12+1
6.6.13-1
6.6.15-1
6.6.15-2
6.7-1~exp1
6.7.1-1~exp1
6.7.4-1~exp1
6.7.7-1
6.7.9-1
6.7.9-2
6.7.12-1~bpo12+1
6.7.12-1
6.8.9-1
6.8.11-1
6.8.12-1~bpo12+1
6.8.12-1
6.9.2-1~exp1
6.9.7-1~bpo12+1
6.9.7-1
6.9.8-1
6.9.9-1
6.9.10-1~bpo12+1
6.9.10-1
6.9.11-1
6.9.12-1
6.10-1~exp1
6.10.1-1~exp1
6.10.3-1
6.10.4-1
6.10.6-1~bpo12+1
6.10.6-1
6.10.7-1
6.10.9-1
6.10.11-1~bpo12+1
6.10.11-1
6.10.12-1
6.11~rc4-1~exp1
6.11~rc5-1~exp1
6.11-1~exp1
6.11.2-1
6.11.4-1
6.11.5-1~bpo12+1
6.11.5-1
6.11.6-1
6.11.7-1
6.11.9-1
6.11.10-1~bpo12+1
6.11.10-1
6.12~rc6-1~exp1
6.12.3-1
6.12.5-1
6.12.6-1
6.12.8-1
6.12.9-1~bpo12+1
6.12.9-1
6.12.9-1+alpha
6.12.10-1
6.12.11-1
6.12.11-1+alpha
6.12.11-1+alpha.1
6.12.12-1~bpo12+1
6.12.12-1
6.12.13-1
6.12.15-1
6.12.16-1
6.12.17-1
6.12.19-1
6.12.20-1
6.12.21-1
6.12.22-1~bpo12+1
6.12.22-1
6.12.25-1
6.12.27-1~bpo12+1
6.12.27-1
6.12.29-1
6.12.30-1~bpo12+1
6.12.30-1
6.12.31-1
6.12.32-1~bpo12+1
6.12.32-1
6.12.33-1~bpo12+1
6.12.33-1
6.12.35-1~bpo12+1
6.12.35-1
6.12.37-1
6.12.38-1
6.13~rc6-1~exp1
6.13~rc7-1~exp1
6.13.2-1~exp1
6.13.3-1~exp1
6.13.4-1~exp1
6.13.5-1~exp1
6.13.6-1~exp1
6.13.7-1~exp1
6.13.8-1~exp1
6.13.9-1~exp1
6.13.10-1~exp1
6.13.11-1~exp1
6.14.3-1~exp1
6.14.5-1~exp1
6.14.6-1~exp1
6.15~rc7-1~exp1
6.15-1~exp1
6.15.1-1~exp1
6.15.2-1~exp1
6.15.3-1~exp1
6.15.4-1~exp1
6.15.5-1~exp1
6.15.6-1~exp1
6.16~rc7-1~exp1
Debian:12 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affected
Affected versions
6.*
6.1.27-1
6.1.37-1
6.1.38-1
6.1.38-2~bpo11+1
6.1.38-2
6.1.38-3
6.1.38-4~bpo11+1
6.1.38-4
6.1.52-1
6.1.55-1~bpo11+1
6.1.55-1
6.1.64-1
6.1.66-1
6.1.67-1
6.1.69-1~bpo11+1
6.1.69-1
6.1.76-1~bpo11+1
6.1.76-1
6.1.82-1
6.1.85-1
6.1.90-1~bpo11+1
6.1.90-1
6.1.94-1~bpo11+1
6.1.94-1
6.1.98-1
6.1.99-1
6.1.106-1
6.1.106-2
6.1.106-3
6.1.112-1
6.1.115-1
6.1.119-1
6.1.123-1
6.1.124-1
6.1.128-1
6.1.129-1
6.1.133-1
6.1.135-1
6.1.137-1
6.1.139-1
6.1.140-1
6.3.1-1~exp1
6.3.2-1~exp1
6.3.4-1~exp1
6.3.5-1~exp1
6.3.7-1~bpo12+1
6.3.7-1
6.3.11-1
6.4~rc6-1~exp1
6.4~rc7-1~exp1
6.4.1-1~exp1
6.4.4-1~bpo12+1
6.4.4-1
6.4.4-2
6.4.4-3~bpo12+1
6.4.4-3
6.4.11-1
6.4.13-1
6.5~rc4-1~exp1
6.5~rc6-1~exp1
6.5~rc7-1~exp1
6.5.1-1~exp1
6.5.3-1~bpo12+1
6.5.3-1
6.5.6-1
6.5.8-1
6.5.10-1~bpo12+1
6.5.10-1
6.5.13-1
6.6.3-1~exp1
6.6.4-1~exp1
6.6.7-1~exp1
6.6.8-1
6.6.9-1
6.6.11-1
6.6.13-1~bpo12+1
6.6.13-1
6.6.15-1
6.6.15-2
6.7-1~exp1
6.7.1-1~exp1
6.7.4-1~exp1
6.7.7-1
6.7.9-1
6.7.9-2
6.7.12-1~bpo12+1
6.7.12-1
6.8.9-1
6.8.11-1
6.8.12-1~bpo12+1
6.8.12-1
6.9.2-1~exp1
6.9.7-1~bpo12+1
6.9.7-1
6.9.8-1
6.9.9-1
6.9.10-1~bpo12+1
6.9.10-1
6.9.11-1
6.9.12-1
6.10-1~exp1
6.10.1-1~exp1
6.10.3-1
6.10.4-1
6.10.6-1~bpo12+1
6.10.6-1
6.10.7-1
6.10.9-1
6.10.11-1~bpo12+1
6.10.11-1
6.10.12-1
6.11~rc4-1~exp1
6.11~rc5-1~exp1
6.11-1~exp1
6.11.2-1
6.11.4-1
6.11.5-1~bpo12+1
6.11.5-1
6.11.6-1
6.11.7-1
6.11.9-1
6.11.10-1~bpo12+1
6.11.10-1
6.12~rc6-1~exp1
6.12.3-1
6.12.5-1
6.12.6-1
6.12.8-1
6.12.9-1~bpo12+1
6.12.9-1
6.12.9-1+alpha
6.12.10-1
6.12.11-1
6.12.11-1+alpha
6.12.11-1+alpha.1
6.12.12-1~bpo12+1
6.12.12-1
6.12.13-1
6.12.15-1
6.12.16-1
6.12.17-1
6.12.19-1
6.12.20-1
6.12.21-1
6.12.22-1~bpo12+1
6.12.22-1
6.12.25-1
6.12.27-1~bpo12+1
6.12.27-1
6.12.29-1
6.12.30-1~bpo12+1
6.12.30-1
6.12.31-1
6.12.32-1~bpo12+1
6.12.32-1
6.12.33-1~bpo12+1
6.12.33-1
6.12.35-1~bpo12+1
6.12.35-1
6.12.37-1
6.12.38-1
6.13~rc6-1~exp1
6.13~rc7-1~exp1
6.13.2-1~exp1
6.13.3-1~exp1
6.13.4-1~exp1
6.13.5-1~exp1
6.13.6-1~exp1
6.13.7-1~exp1
6.13.8-1~exp1
6.13.9-1~exp1
6.13.10-1~exp1
6.13.11-1~exp1
6.14.3-1~exp1
6.14.5-1~exp1
6.14.6-1~exp1
6.15~rc7-1~exp1
6.15-1~exp1
6.15.1-1~exp1
6.15.2-1~exp1
6.15.3-1~exp1
6.15.4-1~exp1
6.15.5-1~exp1
6.15.6-1~exp1
6.16~rc7-1~exp1
Debian:13 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affected
Affected versions
6.*
6.12.38-1
6.13~rc6-1~exp1
6.13~rc7-1~exp1
6.13.2-1~exp1
6.13.3-1~exp1
6.13.4-1~exp1
6.13.5-1~exp1
6.13.6-1~exp1
6.13.7-1~exp1
6.13.8-1~exp1
6.13.9-1~exp1
6.13.10-1~exp1
6.13.11-1~exp1
6.14.3-1~exp1
6.14.5-1~exp1
6.14.6-1~exp1
6.15~rc7-1~exp1
6.15-1~exp1
6.15.1-1~exp1
6.15.2-1~exp1
6.15.3-1~exp1
6.15.4-1~exp1
6.15.5-1~exp1
6.15.6-1~exp1
6.16~rc7-1~exp1