Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: net_sched: hfsc: Fix a UAF vulnerability in class handling This patch fixes a Use-After-Free vulnerability in the HFSC qdisc class handling. The issue occurs due to a time-of-check/time-of-use condition in hfsc_change_class() when working with certain child qdiscs like netem or codel. The vulnerability works as follows: 1. hfsc_change_class() checks if a class has packets (q.qlen != 0) 2. It then calls qdisc_peek_len(), which for certain qdiscs (e.g., codel, netem) might drop packets and empty the queue 3. The code continues assuming the queue is still non-empty, adding the class to vttree 4. This breaks HFSC scheduler assumptions that only non-empty classes are in vttree 5. Later, when the class is destroyed, this can lead to a Use-After-Free The fix adds a second queue length check after qdisc_peek_len() to verify the queue wasn't emptied.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14 before 28b09a067831f7317c3841812276022d6c940677; affected 21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14 before 39b9095dd3b55d9b2743df038c32138efa34a9de; affected 21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14 before fcc8ede663569c704fb00a702973bd6c00373283; affected 21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14 before 20d584a33e480ae80d105f43e0e7b56784da41b9; affected 21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14 before 3aa852e3605000d5c47035c3fc3a986d14ccfa9f; affected 21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14 before 86cd4641c713455a4f1c8e54c370c598c2b1cee0; affected 21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14 before bb583c88d23b72d8d16453d24856c99bd93dadf5; affected 21f4d5cc25ec0e6e8eb8420dd2c399e6d2fc7d14 before 3df275ef0a6ae181e8428a6589ef5d5231e58b5c |
| Linux / Linux | affected 4.14; unaffected 0 before 4.14; unaffected 5.4.293 through 5.4.*; unaffected 5.10.237 through 5.10.*; unaffected 5.15.181 through 5.15.*; unaffected 6.1.136 through 6.1.*; unaffected 6.6.89 through 6.6.*; unaffected 6.12.26 through 6.12.*; unaffected 6.14.5 through 6.14.*; unaffected 6.15 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/28b09a067831f7317c3841812276022d6c940677
- https://git.kernel.org/stable/c/39b9095dd3b55d9b2743df038c32138efa34a9de
- https://git.kernel.org/stable/c/fcc8ede663569c704fb00a702973bd6c00373283
- https://git.kernel.org/stable/c/20d584a33e480ae80d105f43e0e7b56784da41b9
- https://git.kernel.org/stable/c/3aa852e3605000d5c47035c3fc3a986d14ccfa9f
- https://git.kernel.org/stable/c/86cd4641c713455a4f1c8e54c370c598c2b1cee0
- https://git.kernel.org/stable/c/bb583c88d23b72d8d16453d24856c99bd93dadf5
- https://git.kernel.org/stable/c/3df275ef0a6ae181e8428a6589ef5d5231e58b5c
ADP enrichment
No English description supplied.
No English description supplied.
No references supplied.