| 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-2021-47109: neighbour: allow NUD_NOARP entries to be forced GCed |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| neighbour: allow NUD_NOARP entries to be forced GCed |
| |
| IFF_POINTOPOINT interfaces use NUD_NOARP entries for IPv6. It's possible to |
| fill up the neighbour table with enough entries that it will overflow for |
| valid connections after that. |
| |
| This behaviour is more prevalent after commit 58956317c8de ("neighbor: |
| Improve garbage collection") is applied, as it prevents removal from |
| entries that are not NUD_FAILED, unless they are more than 5s old. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47109 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.0 with commit 58956317c8de52009d1a38a721474c24aef74fe7 and fixed in 5.4.125 with commit d99029e6aab62aef0a0251588b2867e77e83b137 |
| Issue introduced in 5.0 with commit 58956317c8de52009d1a38a721474c24aef74fe7 and fixed in 5.10.43 with commit d17d47da59f726dc4c87caebda3a50333d7e2fd3 |
| Issue introduced in 5.0 with commit 58956317c8de52009d1a38a721474c24aef74fe7 and fixed in 5.12.10 with commit ddf088d7aaaaacfc836104f2e632b29b1d383cfc |
| Issue introduced in 5.0 with commit 58956317c8de52009d1a38a721474c24aef74fe7 and fixed in 5.13 with commit 7a6b1ab7475fd6478eeaf5c9d1163e7a18125c8f |
| |
| 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-2021-47109 |
| 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/core/neighbour.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/d99029e6aab62aef0a0251588b2867e77e83b137 |
| https://git.kernel.org/stable/c/d17d47da59f726dc4c87caebda3a50333d7e2fd3 |
| https://git.kernel.org/stable/c/ddf088d7aaaaacfc836104f2e632b29b1d383cfc |
| https://git.kernel.org/stable/c/7a6b1ab7475fd6478eeaf5c9d1163e7a18125c8f |
