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| author | Rusty Russell <rusty@rustcorp.com.au> | 2015-05-27 10:59:26 +0930 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2015-08-07 00:32:13 +0100 |
| commit | a8f5259269671acb4f0bdb6e0a53974aa5b351ff (patch) | |
| tree | 787cbd11e534d243f8bafb97d24f35312ad9f28d | |
| parent | a8139dccd98bdece27deac8da46b4145ec7f61c1 (diff) | |
| download | lwn-a8f5259269671acb4f0bdb6e0a53974aa5b351ff.tar.gz lwn-a8f5259269671acb4f0bdb6e0a53974aa5b351ff.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: Ben Hutchings <ben@decadent.org.uk>
| -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 b5fdcb78a75b..34842e5e8b55 100644 --- a/drivers/lguest/core.c +++ b/drivers/lguest/core.c @@ -171,7 +171,7 @@ 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); } /* |