[PATCH] free_page(0) freed pagenr 0x40000

sys_mount(), and probably others, calls free_page(0) when no page was got. free_pages() allows for this explicitly if CONFIG_DISCONTIGMEM, and _appears_ to allow for it generally by testing VALID_PAGE() - but that test is inadequate, if over 1GB of memory then pagenr 0x4 can be wrongly freed

[PATCH] free_page(0) freed pagenr 0x40000

sys_mount(), and probably others, calls free_page(0) when no page was got. free_pages() allows for this explicitly if CONFIG_DISCONTIGMEM, and _appears_ to allow for it generally by testing VALID_PAGE() - but that test is inadequate, if over 1GB of memory then pagenr 0x4 can be wrongly freed