| 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-2024-38558: net: openvswitch: fix overwriting ct original tuple for ICMPv6 |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| net: openvswitch: fix overwriting ct original tuple for ICMPv6 |
| |
| OVS_PACKET_CMD_EXECUTE has 3 main attributes: |
| - OVS_PACKET_ATTR_KEY - Packet metadata in a netlink format. |
| - OVS_PACKET_ATTR_PACKET - Binary packet content. |
| - OVS_PACKET_ATTR_ACTIONS - Actions to execute on the packet. |
| |
| OVS_PACKET_ATTR_KEY is parsed first to populate sw_flow_key structure |
| with the metadata like conntrack state, input port, recirculation id, |
| etc. Then the packet itself gets parsed to populate the rest of the |
| keys from the packet headers. |
| |
| Whenever the packet parsing code starts parsing the ICMPv6 header, it |
| first zeroes out fields in the key corresponding to Neighbor Discovery |
| information even if it is not an ND packet. |
| |
| It is an 'ipv6.nd' field. However, the 'ipv6' is a union that shares |
| the space between 'nd' and 'ct_orig' that holds the original tuple |
| conntrack metadata parsed from the OVS_PACKET_ATTR_KEY. |
| |
| ND packets should not normally have conntrack state, so it's fine to |
| share the space, but normal ICMPv6 Echo packets or maybe other types of |
| ICMPv6 can have the state attached and it should not be overwritten. |
| |
| The issue results in all but the last 4 bytes of the destination |
| address being wiped from the original conntrack tuple leading to |
| incorrect packet matching and potentially executing wrong actions |
| in case this packet recirculates within the datapath or goes back |
| to userspace. |
| |
| ND fields should not be accessed in non-ND packets, so not clearing |
| them should be fine. Executing memset() only for actual ND packets to |
| avoid the issue. |
| |
| Initializing the whole thing before parsing is needed because ND packet |
| may not contain all the options. |
| |
| The issue only affects the OVS_PACKET_CMD_EXECUTE path and doesn't |
| affect packets entering OVS datapath from network interfaces, because |
| in this case CT metadata is populated from skb after the packet is |
| already parsed. |
| |
| The Linux kernel CVE team has assigned CVE-2024-38558 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.11 with commit 9dd7f8907c3705dc7a7a375d1c6e30b06e6daffc and fixed in 4.19.316 with commit 6a51ac92bf35d34b4996d6eb67e2fe469f573b11 |
| Issue introduced in 4.11 with commit 9dd7f8907c3705dc7a7a375d1c6e30b06e6daffc and fixed in 5.4.278 with commit 0b532f59437f688563e9c58bdc1436fefa46e3b5 |
| Issue introduced in 4.11 with commit 9dd7f8907c3705dc7a7a375d1c6e30b06e6daffc and fixed in 5.10.219 with commit 5ab6aecbede080b44b8e34720ab72050bf1e6982 |
| Issue introduced in 4.11 with commit 9dd7f8907c3705dc7a7a375d1c6e30b06e6daffc and fixed in 5.15.161 with commit 483eb70f441e2df66ade78aa7217e6e4caadfef3 |
| Issue introduced in 4.11 with commit 9dd7f8907c3705dc7a7a375d1c6e30b06e6daffc and fixed in 6.1.93 with commit 9ec8b0ccadb908d92f7ee211a4eff05fd932f3f6 |
| Issue introduced in 4.11 with commit 9dd7f8907c3705dc7a7a375d1c6e30b06e6daffc and fixed in 6.6.33 with commit 78741b4caae1e880368cb2f5110635f3ce45ecfd |
| Issue introduced in 4.11 with commit 9dd7f8907c3705dc7a7a375d1c6e30b06e6daffc and fixed in 6.8.12 with commit 431e9215576d7b728f3f53a704d237a520092120 |
| Issue introduced in 4.11 with commit 9dd7f8907c3705dc7a7a375d1c6e30b06e6daffc and fixed in 6.9.3 with commit d73fb8bddf89503c9fae7c42e50d44c89909aad6 |
| Issue introduced in 4.11 with commit 9dd7f8907c3705dc7a7a375d1c6e30b06e6daffc and fixed in 6.10 with commit 7c988176b6c16c516474f6fceebe0f055af5eb56 |
| |
| 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-2024-38558 |
| 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/openvswitch/flow.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/6a51ac92bf35d34b4996d6eb67e2fe469f573b11 |
| https://git.kernel.org/stable/c/0b532f59437f688563e9c58bdc1436fefa46e3b5 |
| https://git.kernel.org/stable/c/5ab6aecbede080b44b8e34720ab72050bf1e6982 |
| https://git.kernel.org/stable/c/483eb70f441e2df66ade78aa7217e6e4caadfef3 |
| https://git.kernel.org/stable/c/9ec8b0ccadb908d92f7ee211a4eff05fd932f3f6 |
| https://git.kernel.org/stable/c/78741b4caae1e880368cb2f5110635f3ce45ecfd |
| https://git.kernel.org/stable/c/431e9215576d7b728f3f53a704d237a520092120 |
| https://git.kernel.org/stable/c/d73fb8bddf89503c9fae7c42e50d44c89909aad6 |
| https://git.kernel.org/stable/c/7c988176b6c16c516474f6fceebe0f055af5eb56 |
