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scenario hard Analyze chmod-recursive-trap 2 points

Question 42. CSCD240-E1-C

chmod -R 644 /etc/ssh — what broke and why?

Work the drill

Answer on paper or in a terminal before revealing the ideal answer.

Ideal answer
Directories lost their execute (x) bit. You can no longer cd into /etc/ssh or read files inside. Applying literal 644 recursively to both files AND directories removes directory traversal.

Misconception bank

Each row below is a plausible wrong answer, the thinking that produces it, and the remedy that corrects the misconception. These are the foundation of the multiple-choice framing and the targeted feedback a student receives after answering.

Nothing broke
Misconception. Misses the directory-x implication.
Remedy. Distinguish file vs dir semantics of x.

Authority mappings

Hover any chip for the mapping justification; click to open the authority record.

DCWF tasks: T0136
KU outcomes: CO-M9-O2
KU topics: CD-OSC-T7

Course-artifact links

Lectures

  • CSCD240-S26-L06. Permissions part 2: chmod octal + symbolic, directory x bit