lguest: fix out-by-one error in address checking.
This bug has been there since day 1; addresses in the top guest physical page weren't considered valid. You could map that page (the check in check_gpte() is correct), but if a guest tried to put a pagetable there we'd check that address manually when walking it, and kill the guest. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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@ -173,7 +173,7 @@ static void unmap_switcher(void)
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bool lguest_address_ok(const struct lguest *lg,
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bool lguest_address_ok(const struct lguest *lg,
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unsigned long addr, unsigned long len)
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unsigned long addr, unsigned long len)
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{
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{
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return (addr+len) / PAGE_SIZE < lg->pfn_limit && (addr+len >= addr);
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return addr+len <= lg->pfn_limit * PAGE_SIZE && (addr+len >= addr);
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}
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}
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/*
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/*
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