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authorRusty Russell <rusty@rustcorp.com.au>2015-05-27 10:59:26 +0930
committerLinus Torvalds <torvalds@linux-foundation.org>2015-05-27 09:57:21 -0700
commit83a35114d0e4583e6b0ca39502e68b6a92e2910c (patch)
treef6a10dde40090d72e1dae2911057b3208d959415
parent3cfd4ba7d37b52eb965ed05209647072932dfd0a (diff)
downloadop-kernel-dev-83a35114d0e4583e6b0ca39502e68b6a92e2910c.zip
op-kernel-dev-83a35114d0e4583e6b0ca39502e68b6a92e2910c.tar.gz
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>
-rw-r--r--drivers/lguest/core.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c
index 7dc93aa..312ffd3 100644
--- a/drivers/lguest/core.c
+++ b/drivers/lguest/core.c
@@ -173,7 +173,7 @@ static void unmap_switcher(void)
bool lguest_address_ok(const struct lguest *lg,
unsigned long addr, unsigned long len)
{
- return (addr+len) / PAGE_SIZE < lg->pfn_limit && (addr+len >= addr);
+ return addr+len <= lg->pfn_limit * PAGE_SIZE && (addr+len >= addr);
}
/*
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