In the Linux kernel, the following vulnerability has been resolved:

comedi: fix divide-by-zero in comedi_buf_munge()

The comedi_buf_munge() function performs a modulo operation
`async->munge_chan %= async->cmd.chanlist_len` without first
checking if chanlist_len is zero. If a user program submits a command with
chanlist_len set to zero, this causes a divide-by-zero error when the device
processes data in the interrupt handler path.

Add a check for zero chanlist_len at the beginning of the
function, similar to the existing checks for !map and
CMDF_RAWDATA flag. When chanlist_len is zero, update
munge_count and return early, indicating the data was
handled without munging.

This prevents potential kernel panics from malformed user commands.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 31 Oct 2025 10:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: comedi: fix divide-by-zero in comedi_buf_munge() The comedi_buf_munge() function performs a modulo operation `async->munge_chan %= async->cmd.chanlist_len` without first checking if chanlist_len is zero. If a user program submits a command with chanlist_len set to zero, this causes a divide-by-zero error when the device processes data in the interrupt handler path. Add a check for zero chanlist_len at the beginning of the function, similar to the existing checks for !map and CMDF_RAWDATA flag. When chanlist_len is zero, update munge_count and return early, indicating the data was handled without munging. This prevents potential kernel panics from malformed user commands.
Title comedi: fix divide-by-zero in comedi_buf_munge()
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-10-31T09:41:46.740Z

Reserved: 2025-04-16T07:20:57.166Z

Link: CVE-2025-40106

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-10-31T10:15:50.520

Modified: 2025-10-31T10:15:50.520

Link: CVE-2025-40106

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.