CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's handling of channel command words (CCWs) in the s390/vfio_ccw module, where an out-of-bounds check could allow access to memory beyond the allocated CCW array. This flaw could potentially lead to memory corruption or denial of service, making it critical for organizations using affected Linux systems, particularly those in environments relying on s390 architecture, to prioritize applying the fix. Users should ensure their systems are updated to prevent exploitation of this vulnerability.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: s390/vfio_ccw: Fix out of bounds check on CCW array The routine ccwchain_calc_length() counts the number of channel command words (CCWs) that are chained together in a single channel program, and rejects anything larger than CCWCHAIN_LEN_MAX (256) CCWs. The loop itself is "do..while (count < 257)", and while the logic in is_cpa_within_range() correctly adjusts between the 0-index array of CCWs and the count of CCWs starting at 1, this means it would look at a possible 257th CCW before ending the loop and (correctly) returning an error. Fix this by restructuring the loop to break as soon as 256 CCWs (thus indexes 0-255) are examined, without looking at memory outside the range.