CVEvulnerability
CVE-2023-54181
- Status
- Deferred
- Published
- 2025-12-30
- Last modified
- 2026-06-17
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Description
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix issue in verifying allow_ptr_leaks
After we converted the capabilities of our networking-bpf program from
cap_sys_admin to cap_net_admin+cap_bpf, our networking-bpf program
failed to start. Because it failed the bpf verifier, and the error log
is "R3 pointer comparison prohibited".
A simple reproducer as follows,
SEC("cls-ingress")
int ingress(struct __sk_buff *skb)
{
struct iphdr *iph = (void *)(long)skb->data + sizeof(struct ethhdr);
if ((long)(iph + 1) > (long)skb->data_end)
return TC_ACT_STOLEN;
return TC_ACT_OK;
}
Per discussion with Yonghong and Alexei [1], comparison of two packet
pointers is not a pointer leak. This patch fixes it.
Our local kernel is 6.1.y and we expect this fix to be backported to
6.1.y, so stable is CCed.
[1]. https://lore.kernel.org/bpf/CAADnVQ+Nmspr7Si+pxWn8zkE7hX-7s93ugwC+94aXSy4uQ9vBg@mail.gmail.com/
References
- https://git.kernel.org/stable/c/5927f0172d2809d8fc09c1ba667280b0387e9f73 git.kernel.org
- https://git.kernel.org/stable/c/acfdc8b77016c8e648aadc283177546c88083dd3 git.kernel.org
- https://git.kernel.org/stable/c/c96c67991aac6401b4c6996093bccb704bb2ea4b git.kernel.org
- https://git.kernel.org/stable/c/d75e30dddf73449bc2d10bb8e2f1a2c446bc67a2 git.kernel.org