| 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-2022-49622: netfilter: nf_tables: avoid skb access on nf_stolen |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| netfilter: nf_tables: avoid skb access on nf_stolen |
| |
| When verdict is NF_STOLEN, the skb might have been freed. |
| |
| When tracing is enabled, this can result in a use-after-free: |
| 1. access to skb->nf_trace |
| 2. access to skb->mark |
| 3. computation of trace id |
| 4. dump of packet payload |
| |
| To avoid 1, keep a cached copy of skb->nf_trace in the |
| trace state struct. |
| Refresh this copy whenever verdict is != STOLEN. |
| |
| Avoid 2 by skipping skb->mark access if verdict is STOLEN. |
| |
| 3 is avoided by precomputing the trace id. |
| |
| Only dump the packet when verdict is not "STOLEN". |
| |
| The Linux kernel CVE team has assigned CVE-2022-49622 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.18.13 with commit 0016d5d46d7440729a3132f61a8da3bf7f84e2ba |
| Fixed in 5.19 with commit e34b9ed96ce3b06c79bf884009b16961ca478f87 |
| |
| 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-2022-49622 |
| 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: |
| include/net/netfilter/nf_tables.h |
| net/netfilter/nf_tables_core.c |
| net/netfilter/nf_tables_trace.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/0016d5d46d7440729a3132f61a8da3bf7f84e2ba |
| https://git.kernel.org/stable/c/e34b9ed96ce3b06c79bf884009b16961ca478f87 |
