fix(security): block symlink creation in RealFs to prevent sandbox escape#1027
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fix(security): block symlink creation in RealFs to prevent sandbox escape#1027
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…cape Symlink creation in RealFs is now completely blocked. Even though bashkit doesn't follow symlinks internally (TM-ESC-002), external processes sharing the directory tree would follow them, enabling reads/writes to arbitrary host paths outside the sandbox. Closes #979
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Summary
Why
ln -s /etc/passwd linkinside a RealFs sandbox created an actual symlink on the host. While bashkit doesn't follow symlinks internally (TM-ESC-002), CI runners or other container processes sharing the directory would follow them.Tests
realfs_symlink_absolute_escape_blocked—ln -s /etc/passwdis rejectedrealfs_symlink_relative_escape_blocked—ln -s ../../../../etc/passwdis rejectedCloses #979