CVE-2026-93125bpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Oct 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae before 93a20b14f8627b2d3486e3ec1d3f2e7275a506ec; from eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae before 56a3846830ac95a472297d0cbba75cbff29540bb; from eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae before 2aaf67f0516fde29620d0edfc29c01b9ea7ad430 | CNA record |
References
- https://git.kernel.org/stable/c/93a20b14f8627b2d3486e3ec1d3f2e7275a506ec
- https://git.kernel.org/stable/c/56a3846830ac95a472297d0cbba75cbff29540bb
- https://git.kernel.org/stable/c/2aaf67f0516fde29620d0edfc29c01b9ea7ad430
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.