CVE-2026-64085
In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/adm1266) bounce blackbox records through a protocol-sized buffer adm1266_pmbus_block_xfer() copies the device-supplied block payload into the caller-provided buffer using…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.14%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/adm1266) bounce blackbox records through a protocol-sized buffer adm1266_pmbus_block_xfer() copies the device-supplied block payload into the caller-provided buffer using the device-supplied length: memcpy(data_r, &msgs[1].buf[1], msgs[1].buf[0]); The helper does not know how large data_r is and trusts the device to return at most one record's worth of bytes. adm1266_nvmem_read_blackbox() violates that contract: it advances read_buff inside data->dev_mem in ADM1266_BLACKBOX_SIZE (64-byte) strides while the helper is willing to write up to ADM1266_PMBUS_BLOCK_MAX (255) bytes. A device that returns more than 64 bytes on the trailing record (read_buff offset 1984 in the 2048-byte dev_mem allocation) overflows dev_mem by up to 191 bytes before the post-call if (ret != ADM1266_BLACKBOX_SIZE) return -EIO; can reject the response. Contain the fix in the caller without changing the helper signature: read each record into a 255-byte local bounce buffer that matches the helper's maximum output, validate the returned length, and only then copy exactly ADM1266_BLACKBOX_SIZE bytes into the dev_mem slot.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.14% probability · 4th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-787
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/43cae21424ff8e33894a0f86c6b80b840c049fd7Patch
- https://git.kernel.org/stable/c/6098634cfa711f11a8d65368dc51ec8f7c8241baPatch
- https://git.kernel.org/stable/c/60c4b9fe1a3dd012014b1f561a6928a0b5db1126Patch
- https://git.kernel.org/stable/c/7896d87cbb05e097efc113243d4e38f9f8cea16cPatch
- https://git.kernel.org/stable/c/83e039f0a43e0708515b0479cb7690fb93faaaa0Patch
- https://git.kernel.org/stable/c/97a9cf2a8217ca1cdaf48cb9ab26e471632c7e7fPatch
- https://git.kernel.org/stable/c/9d5309500b4607b7198e19f0a3fa13eb864cd5fbPatch
- https://git.kernel.org/stable/c/dd47b8c4a0a8ced442da3f008db28fbbd31feaf0Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.