CVE-2025-40106

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxed9eccbe8970f6eedc1b978c157caf1251a896d4 < 4ffea48c69cb2b96a281cb7e5e42d706996631dbaffected
LinuxLinuxed9eccbe8970f6eedc1b978c157caf1251a896d4 < 8f3e4cd9be4b47246ea73ce5e3e0fa2f57f0d10caffected
LinuxLinuxed9eccbe8970f6eedc1b978c157caf1251a896d4 < 2670932f2465793fea1ef073e40883e8390fa4d9affected
LinuxLinuxed9eccbe8970f6eedc1b978c157caf1251a896d4 < 6db19822512396be1a3e1e20c16c97270285ba1aaffected
LinuxLinuxed9eccbe8970f6eedc1b978c157caf1251a896d4 < d4854eff25efb06d0d84c13e7129bbdba4125f8caffected
LinuxLinuxed9eccbe8970f6eedc1b978c157caf1251a896d4 < a4bb5d1bc2f238461bcbe5303eb500466690bb2caffected
LinuxLinuxed9eccbe8970f6eedc1b978c157caf1251a896d4 < 55520f65fd447e04099a2c44185453c18ea73b7eaffected
LinuxLinuxed9eccbe8970f6eedc1b978c157caf1251a896d4 < 87b318ba81dda2ee7b603f4f6c55e78ec3e95974affected
LinuxLinux2.6.29affected
LinuxLinux0 < 2.6.29unaffected
LinuxLinux5.4.301 <= 5.4.*unaffected
LinuxLinux5.10.246 <= 5.10.*unaffected
LinuxLinux5.15.196 <= 5.15.*unaffected
LinuxLinux6.1.158 <= 6.1.*unaffected
LinuxLinux6.6.115 <= 6.6.*unaffected
LinuxLinux6.12.56 <= 6.12.*unaffected
LinuxLinux6.17.6 <= 6.17.*unaffected
LinuxLinux6.18 <= *unaffected

Weaknesses

References