{"id":"CVE-2026-93125","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max\n\ncheck_kfunc_args() detects a kfunc argument named rdonly_buf_size or\nrdwr_buf_size and stores reg-…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max\n\ncheck_kfunc_args() detects a kfunc argument named rdonly_buf_size or\nrdwr_buf_size and stores reg-…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae < 56a3846830ac95a472297d0cbba75cbff29540bb","Linux >= eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae < 2aaf67f0516fde29620d0edfc29c01b9ea7ad430","Linux 6.1"],"published":"2026-09-17","updated":"2026-09-18","sourceUpdated":"2026-09-18T18:18:21.907","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-93125","references":[{"url":"https://git.kernel.org/stable/c/2aaf67f0516fde29620d0edfc29c01b9ea7ad430","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/56a3846830ac95a472297d0cbba75cbff29540bb","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.0012,"epssPercentile":0.02115,"ingestedAt":"2026-09-17T16:21:47.749Z","slug":"CVE-2026-93125","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max\n\ncheck_kfunc_args() detects a kfunc argument named rdonly_buf_size or\nrdwr_buf_size and stores reg->var_off.value into meta->r0_size, a u64,\nand does not bound it. check_kfunc_call() later copies that value into\nthe returned register's mem_size field:\n\n  meta->r0_size = reg->var_off.value;\n  ...\n  regs[BPF_REG_0].mem_size = meta.r0_size;\n\nregs[BPF_REG_0].mem_size is u32. A constant whose upper 32 bits are set\ngets truncated instead of causing a load-time rejection, so the verifier\nrecords a PTR_TO_MEM register with an approximately 4 GiB mem_size for\nwhatever allocation the kfunc returned. A later access check against\nthat register uses the truncated, wrong bound.\n\nReject rdonly_buf_size/rdwr_buf_size values that exceed U32_MAX at the\npoint meta->r0_size is set.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":207385,"id":"CVE-2026-93125","ts":1789757342606,"field":"cvss","old":null,"new":"7.8"},{"seq":207384,"id":"CVE-2026-93125","ts":1789757342606,"field":"severity","old":"none","new":"high"}]}