| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2022-49110: netfilter: conntrack: revisit gc autotuning |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| netfilter: conntrack: revisit gc autotuning |
| |
| as of commit 4608fdfc07e1 |
| ("netfilter: conntrack: collect all entries in one cycle") |
| conntrack gc was changed to run every 2 minutes. |
| |
| On systems where conntrack hash table is set to large value, most evictions |
| happen from gc worker rather than the packet path due to hash table |
| distribution. |
| |
| This causes netlink event overflows when events are collected. |
| |
| This change collects average expiry of scanned entries and |
| reschedules to the average remaining value, within 1 to 60 second interval. |
| |
| To avoid event overflows, reschedule after each bucket and add a |
| limit for both run time and number of evictions per run. |
| |
| If more entries have to be evicted, reschedule and restart 1 jiffy |
| into the future. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49110 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.15.34 with commit 58d52743ae85d28c9335c6034d6ce350b8689951 |
| Fixed in 5.16.20 with commit 7cd361d5e6d986c0d4cafb9ceaa803359048ae15 |
| Fixed in 5.17.3 with commit 592e57591826f3d09c28d755a39ea8e9d13705ad |
| Fixed in 5.18 with commit 2cfadb761d3d0219412fd8150faea60c7e863833 |
| |
| 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-2022-49110 |
| 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/netfilter/nf_conntrack_core.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/58d52743ae85d28c9335c6034d6ce350b8689951 |
| https://git.kernel.org/stable/c/7cd361d5e6d986c0d4cafb9ceaa803359048ae15 |
| https://git.kernel.org/stable/c/592e57591826f3d09c28d755a39ea8e9d13705ad |
| https://git.kernel.org/stable/c/2cfadb761d3d0219412fd8150faea60c7e863833 |
