CVE-2024-50161 bpf: Check the remaining info_cnt before repeating btf fields
A missing bounds check in the Linux kernel BPF subsystem allows an out-of-bounds array index, leading to a kernel crash and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-50161?
CVE-2024-50161 is a high-severity vulnerability in Linux kernel, published on 7 Nov 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-129
Which versions are affected by CVE-2024-50161?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-50161?
Apply the vendor's patch.
Is CVE-2024-50161 being exploited?
There is no known exploitation of CVE-2024-50161 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-50161, DEBIAN-CVE-2024-50161, GHSA-9wrc-jcvc-7hxx, UBUNTU-CVE-2024-50161.