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Hayzam Sherif
1cd9aa5cbb
When VBE is unavailable, vbe_init() frees the controller information buffer and sets vbe to NULL. Console initialization still calls vbe_default_mode(), which reaches an unguarded memset() in vbe_find_mode_xydm(). Under BTX, the null write can overwrite the loader's own code and cause a later protection fault. Guard vbe_default_mode() with vbe_check(), as the other public functions in vbe.c already do, and return 0 to indicate that no graphics mode is available. This allows console initialization to continue on headless systems. Reviewed by: rmoeller, imp MFC ater: 2 weeks Differential Revision: https://reviews.freebsd.org/D61145