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| author | Rusty Russell <rusty@rustcorp.com.au> | 2015-05-27 10:59:26 +0930 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-06-06 08:19:32 -0700 |
| commit | e93327e02e4200f321bc2f0838fbb46e06b8646f (patch) | |
| tree | 948ddf3550c2efaa2b9b0bb262ce7c8f01af7030 | |
| parent | 1330ac1cd7b8d6180ccd60eaf271e0954cc58d82 (diff) | |
| download | lwn-e93327e02e4200f321bc2f0838fbb46e06b8646f.tar.gz lwn-e93327e02e4200f321bc2f0838fbb46e06b8646f.zip | |
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.c | 2 |
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); } /* |