CVE Catalog

CVE-2026-93125

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.12%

2th percentile - higher than 2% of all known CVEs

Summary

In the Linux kernel, the BPF subsystem fails to validate the rdonly_buf_size and rdwr_buf_size kfunc arguments. Values exceeding U32_MAX are not rejected but truncated when assigned to the u32 mem_size field, causing the verifier to record an incorrect memory size bound.

Risk Assessment

The BPF verifier may operate on incorrect memory bounds, potentially enabling out-of-bounds access and privilege escalation in the kernel.

Recommendation

Update the Linux kernel to a version containing the BPF kfunc argument validation fix.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: bpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max check_kfunc_args() detects a kfunc argument named rdonly_buf_size or rdwr_buf_size and stores reg->var_off.value into meta->r0_size, a u64, and does not bound it. check_kfunc_call() later copies that value into the returned register's mem_size field: meta->r0_size = reg->var_off.value; ... regs[BPF_REG_0].mem_size = meta.r0_size; regs[BPF_REG_0].mem_size is u32. A constant whose upper 32 bits are set gets truncated instead of causing a load-time rejection, so the verifier records a PTR_TO_MEM register with an approximately 4 GiB mem_size for whatever allocation the kfunc returned. A later access check against that register uses the truncated, wrong bound. Reject rdonly_buf_size/rdwr_buf_size values that exceed U32_MAX at the point meta->r0_size is set.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS