| 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-2024-50161: bpf: Check the remaining info_cnt before repeating btf fields |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| bpf: Check the remaining info_cnt before repeating btf fields |
| |
| When trying to repeat the btf fields for array of nested struct, it |
| doesn't check the remaining info_cnt. The following splat will be |
| reported when the value of ret * nelems is greater than BTF_FIELDS_MAX: |
| |
| ------------[ cut here ]------------ |
| UBSAN: array-index-out-of-bounds in ../kernel/bpf/btf.c:3951:49 |
| index 11 is out of range for type 'btf_field_info [11]' |
| CPU: 6 UID: 0 PID: 411 Comm: test_progs ...... 6.11.0-rc4+ #1 |
| Tainted: [O]=OOT_MODULE |
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ... |
| Call Trace: |
| <TASK> |
| dump_stack_lvl+0x57/0x70 |
| dump_stack+0x10/0x20 |
| ubsan_epilogue+0x9/0x40 |
| __ubsan_handle_out_of_bounds+0x6f/0x80 |
| ? kallsyms_lookup_name+0x48/0xb0 |
| btf_parse_fields+0x992/0xce0 |
| map_create+0x591/0x770 |
| __sys_bpf+0x229/0x2410 |
| __x64_sys_bpf+0x1f/0x30 |
| x64_sys_call+0x199/0x9f0 |
| do_syscall_64+0x3b/0xc0 |
| entry_SYSCALL_64_after_hwframe+0x4b/0x53 |
| RIP: 0033:0x7fea56f2cc5d |
| ...... |
| </TASK> |
| ---[ end trace ]--- |
| |
| Fix it by checking the remaining info_cnt in btf_repeat_fields() before |
| repeating the btf fields. |
| |
| The Linux kernel CVE team has assigned CVE-2024-50161 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.11 with commit 64e8ee814819f21beeeda00d4119221443d77992 and fixed in 6.11.6 with commit 6f957d972feee9b385ea3ae6530310a84e55ba71 |
| Issue introduced in 6.11 with commit 64e8ee814819f21beeeda00d4119221443d77992 and fixed in 6.12 with commit 797d73ee232dd1833dec4824bc53a22032e97c1c |
| |
| 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-2024-50161 |
| 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: |
| kernel/bpf/btf.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/6f957d972feee9b385ea3ae6530310a84e55ba71 |
| https://git.kernel.org/stable/c/797d73ee232dd1833dec4824bc53a22032e97c1c |
