| 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-2024-50257: netfilter: Fix use-after-free in get_info() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| netfilter: Fix use-after-free in get_info() |
| |
| ip6table_nat module unload has refcnt warning for UAF. call trace is: |
| |
| WARNING: CPU: 1 PID: 379 at kernel/module/main.c:853 module_put+0x6f/0x80 |
| Modules linked in: ip6table_nat(-) |
| CPU: 1 UID: 0 PID: 379 Comm: ip6tables Not tainted 6.12.0-rc4-00047-gc2ee9f594da8-dirty #205 |
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), |
| BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 |
| RIP: 0010:module_put+0x6f/0x80 |
| Call Trace: |
| <TASK> |
| get_info+0x128/0x180 |
| do_ip6t_get_ctl+0x6a/0x430 |
| nf_getsockopt+0x46/0x80 |
| ipv6_getsockopt+0xb9/0x100 |
| rawv6_getsockopt+0x42/0x190 |
| do_sock_getsockopt+0xaa/0x180 |
| __sys_getsockopt+0x70/0xc0 |
| __x64_sys_getsockopt+0x20/0x30 |
| do_syscall_64+0xa2/0x1a0 |
| entry_SYSCALL_64_after_hwframe+0x77/0x7f |
| |
| Concurrent execution of module unload and get_info() trigered the warning. |
| The root cause is as follows: |
| |
| cpu0 cpu1 |
| module_exit |
| //mod->state = MODULE_STATE_GOING |
| ip6table_nat_exit |
| xt_unregister_template |
| kfree(t) |
| //removed from templ_list |
| getinfo() |
| t = xt_find_table_lock |
| list_for_each_entry(tmpl, &xt_templates[af]...) |
| if (strcmp(tmpl->name, name)) |
| continue; //table not found |
| try_module_get |
| list_for_each_entry(t, &xt_net->tables[af]...) |
| return t; //not get refcnt |
| module_put(t->me) //uaf |
| unregister_pernet_subsys |
| //remove table from xt_net list |
| |
| While xt_table module was going away and has been removed from |
| xt_templates list, we couldnt get refcnt of xt_table->me. Check |
| module in xt_net->tables list re-traversal to fix it. |
| |
| The Linux kernel CVE team has assigned CVE-2024-50257 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.15 with commit fdacd57c79b79a03c7ca88f706ad9fb7b46831c1 and fixed in 5.15.171 with commit ba22ea01348384df19cc1fabc7964be6e7189749 |
| Issue introduced in 5.15 with commit fdacd57c79b79a03c7ca88f706ad9fb7b46831c1 and fixed in 6.1.116 with commit cb7c388b5967946f097afdb759b7c860305f2d96 |
| Issue introduced in 5.15 with commit fdacd57c79b79a03c7ca88f706ad9fb7b46831c1 and fixed in 6.6.60 with commit 6a1f088f9807f5166f58902d26246d0b88da03a8 |
| Issue introduced in 5.15 with commit fdacd57c79b79a03c7ca88f706ad9fb7b46831c1 and fixed in 6.11.7 with commit bab3bb35c03b263c486833d50d50c081d9e9832b |
| Issue introduced in 5.15 with commit fdacd57c79b79a03c7ca88f706ad9fb7b46831c1 and fixed in 6.12 with commit f48d258f0ac540f00fa617dac496c4c18b5dc2fa |
| |
| 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-2024-50257 |
| 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/x_tables.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/ba22ea01348384df19cc1fabc7964be6e7189749 |
| https://git.kernel.org/stable/c/cb7c388b5967946f097afdb759b7c860305f2d96 |
| https://git.kernel.org/stable/c/6a1f088f9807f5166f58902d26246d0b88da03a8 |
| https://git.kernel.org/stable/c/bab3bb35c03b263c486833d50d50c081d9e9832b |
| https://git.kernel.org/stable/c/f48d258f0ac540f00fa617dac496c4c18b5dc2fa |
