| From bippy-1.2.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2025-37915: net_sched: drr: Fix double list add in class with netem as child qdisc |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| net_sched: drr: Fix double list add in class with netem as child qdisc |
| |
| As described in Gerrard's report [1], there are use cases where a netem |
| child qdisc will make the parent qdisc's enqueue callback reentrant. |
| In the case of drr, there won't be a UAF, but the code will add the same |
| classifier to the list twice, which will cause memory corruption. |
| |
| In addition to checking for qlen being zero, this patch checks whether the |
| class was already added to the active_list (cl_is_active) before adding |
| to the list to cover for the reentrant case. |
| |
| [1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/ |
| |
| The Linux kernel CVE team has assigned CVE-2025-37915 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.0 with commit 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea and fixed in 5.4.294 with commit 5da3aad1a13e7edb8ff0778a444ccf49930313e9 |
| Issue introduced in 5.0 with commit 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea and fixed in 5.10.238 with commit 4b07ac06b0a712923255aaf2691637693fc7100d |
| Issue introduced in 5.0 with commit 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea and fixed in 5.15.182 with commit 2968632880f1792007eedd12eeedf7f6e2b7e9f3 |
| Issue introduced in 5.0 with commit 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea and fixed in 6.1.138 with commit 4f0ecf50cdf76da95828578a92f130b653ac2fcf |
| Issue introduced in 5.0 with commit 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea and fixed in 6.6.90 with commit db205b92dfe0501e5b92fb7cf00971d0e44ba3eb |
| Issue introduced in 5.0 with commit 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea and fixed in 6.12.28 with commit 26e75716b94d6ff9be5ea07d63675c4d189f30b4 |
| Issue introduced in 5.0 with commit 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea and fixed in 6.14.6 with commit ab2248110738d4429668140ad22f530a9ee730e1 |
| Issue introduced in 5.0 with commit 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea and fixed in 6.15 with commit f99a3fbf023e20b626be4b0f042463d598050c9a |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2025-37915 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| net/sched/sch_drr.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/5da3aad1a13e7edb8ff0778a444ccf49930313e9 |
| https://git.kernel.org/stable/c/4b07ac06b0a712923255aaf2691637693fc7100d |
| https://git.kernel.org/stable/c/2968632880f1792007eedd12eeedf7f6e2b7e9f3 |
| https://git.kernel.org/stable/c/4f0ecf50cdf76da95828578a92f130b653ac2fcf |
| https://git.kernel.org/stable/c/db205b92dfe0501e5b92fb7cf00971d0e44ba3eb |
| https://git.kernel.org/stable/c/26e75716b94d6ff9be5ea07d63675c4d189f30b4 |
| https://git.kernel.org/stable/c/ab2248110738d4429668140ad22f530a9ee730e1 |
| https://git.kernel.org/stable/c/f99a3fbf023e20b626be4b0f042463d598050c9a |
