summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorRusty Russell <rusty@rustcorp.com.au>2015-05-27 10:59:26 +0930
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-06-06 08:19:32 -0700
commite93327e02e4200f321bc2f0838fbb46e06b8646f (patch)
tree948ddf3550c2efaa2b9b0bb262ce7c8f01af7030
parent1330ac1cd7b8d6180ccd60eaf271e0954cc58d82 (diff)
lguest: fix out-by-one error in address checking.
commit 83a35114d0e4583e6b0ca39502e68b6a92e2910c upstream. 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> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 0bf1e4edf04d..19da22249bd8 100644
--- a/drivers/lguest/core.c
+++ b/drivers/lguest/core.c
@@ -176,7 +176,7 @@ 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);
}
/*