CVE - CVE-2025-37890

CVE-ID
CVE-2025-37890	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
In the Linux kernel, the following vulnerability has been resolved: net_sched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc As described in Gerrard's report [1], we have a UAF case when an hfsc class has a netem child qdisc. The crux of the issue is that hfsc is assuming that checking for cl->qdisc->q.qlen == 0 guarantees that it hasn't inserted the class in the vttree or eltree (which is not true for the netem duplicate case). This patch checks the n_active class variable to make sure that the code won't insert the class in the vttree or eltree twice, catering for the reentrant case. [1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://git.kernel.org/stable/c/141d34391abbb315d68556b7c67ad97885407547 URL:https://git.kernel.org/stable/c/141d34391abbb315d68556b7c67ad97885407547 MISC:https://git.kernel.org/stable/c/2e7093c7a8aba5d4f8809f271488e5babe75e202 URL:https://git.kernel.org/stable/c/2e7093c7a8aba5d4f8809f271488e5babe75e202 MISC:https://git.kernel.org/stable/c/6082a87af4c52f58150d40dec1716011d871ac21 URL:https://git.kernel.org/stable/c/6082a87af4c52f58150d40dec1716011d871ac21 MISC:https://git.kernel.org/stable/c/8df7d37d626430035b413b97cee18396b3450bef URL:https://git.kernel.org/stable/c/8df7d37d626430035b413b97cee18396b3450bef MISC:https://git.kernel.org/stable/c/ac39fd4a757584d78ed062d4f6fd913f83bd98b5 URL:https://git.kernel.org/stable/c/ac39fd4a757584d78ed062d4f6fd913f83bd98b5 MISC:https://git.kernel.org/stable/c/e3e949a39a91d1f829a4890e7dfe9417ac72e4d0 URL:https://git.kernel.org/stable/c/e3e949a39a91d1f829a4890e7dfe9417ac72e4d0
Assigning CNA
kernel.org
Date Record Created
20250416	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20250416)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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