| 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-2022-48935: netfilter: nf_tables: unregister flowtable hooks on netns exit |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| netfilter: nf_tables: unregister flowtable hooks on netns exit |
| |
| Unregister flowtable hooks before they are releases via |
| nf_tables_flowtable_destroy() otherwise hook core reports UAF. |
| |
| BUG: KASAN: use-after-free in nf_hook_entries_grow+0x5a7/0x700 net/netfilter/core.c:142 net/netfilter/core.c:142 |
| Read of size 4 at addr ffff8880736f7438 by task syz-executor579/3666 |
| |
| CPU: 0 PID: 3666 Comm: syz-executor579 Not tainted 5.16.0-rc5-syzkaller #0 |
| Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 |
| Call Trace: |
| <TASK> |
| __dump_stack lib/dump_stack.c:88 [inline] |
| __dump_stack lib/dump_stack.c:88 [inline] lib/dump_stack.c:106 |
| dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106 lib/dump_stack.c:106 |
| print_address_description+0x65/0x380 mm/kasan/report.c:247 mm/kasan/report.c:247 |
| __kasan_report mm/kasan/report.c:433 [inline] |
| __kasan_report mm/kasan/report.c:433 [inline] mm/kasan/report.c:450 |
| kasan_report+0x19a/0x1f0 mm/kasan/report.c:450 mm/kasan/report.c:450 |
| nf_hook_entries_grow+0x5a7/0x700 net/netfilter/core.c:142 net/netfilter/core.c:142 |
| __nf_register_net_hook+0x27e/0x8d0 net/netfilter/core.c:429 net/netfilter/core.c:429 |
| nf_register_net_hook+0xaa/0x180 net/netfilter/core.c:571 net/netfilter/core.c:571 |
| nft_register_flowtable_net_hooks+0x3c5/0x730 net/netfilter/nf_tables_api.c:7232 net/netfilter/nf_tables_api.c:7232 |
| nf_tables_newflowtable+0x2022/0x2cf0 net/netfilter/nf_tables_api.c:7430 net/netfilter/nf_tables_api.c:7430 |
| nfnetlink_rcv_batch net/netfilter/nfnetlink.c:513 [inline] |
| nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] |
| nfnetlink_rcv_batch net/netfilter/nfnetlink.c:513 [inline] net/netfilter/nfnetlink.c:652 |
| nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] net/netfilter/nfnetlink.c:652 |
| nfnetlink_rcv+0x10e6/0x2550 net/netfilter/nfnetlink.c:652 net/netfilter/nfnetlink.c:652 |
| |
| __nft_release_hook() calls nft_unregister_flowtable_net_hooks() which |
| only unregisters the hooks, then after RCU grace period, it is |
| guaranteed that no packets add new entries to the flowtable (no flow |
| offload rules and flowtable hooks are reachable from packet path), so it |
| is safe to call nf_flow_table_free() which cleans up the remaining |
| entries from the flowtable (both software and hardware) and it unbinds |
| the flow_block. |
| |
| The Linux kernel CVE team has assigned CVE-2022-48935 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.5 with commit ff4bf2f42a40e7dff28379f085b64df322c70b45 and fixed in 4.19.316 with commit 88c795491bf45a8c08a0f94c9ca4f13722e51013 |
| Issue introduced in 5.5 with commit ff4bf2f42a40e7dff28379f085b64df322c70b45 and fixed in 5.4.262 with commit b05a24cc453e3cd51b0c79e3c583b5d495eba1d6 |
| Issue introduced in 5.5 with commit ff4bf2f42a40e7dff28379f085b64df322c70b45 and fixed in 5.10.198 with commit e51f30826bc5384801df98d76109c94953d1df64 |
| Issue introduced in 5.5 with commit ff4bf2f42a40e7dff28379f085b64df322c70b45 and fixed in 5.15.26 with commit 8ffb8ac3448845f65634889b051bd65e4dee484b |
| Issue introduced in 5.5 with commit ff4bf2f42a40e7dff28379f085b64df322c70b45 and fixed in 5.16.12 with commit b4fcc081e527aa2ce12e956912fc47e251f6bd27 |
| Issue introduced in 5.5 with commit ff4bf2f42a40e7dff28379f085b64df322c70b45 and fixed in 5.17 with commit 6069da443bf65f513bb507bb21e2f87cfb1ad0b6 |
| |
| 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-2022-48935 |
| 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_tables_api.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/88c795491bf45a8c08a0f94c9ca4f13722e51013 |
| https://git.kernel.org/stable/c/b05a24cc453e3cd51b0c79e3c583b5d495eba1d6 |
| https://git.kernel.org/stable/c/e51f30826bc5384801df98d76109c94953d1df64 |
| https://git.kernel.org/stable/c/8ffb8ac3448845f65634889b051bd65e4dee484b |
| https://git.kernel.org/stable/c/b4fcc081e527aa2ce12e956912fc47e251f6bd27 |
| https://git.kernel.org/stable/c/6069da443bf65f513bb507bb21e2f87cfb1ad0b6 |
