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| author |   Rusty Russell <rusty@rustcorp.com.au> | 2015-05-27 10:59:26 +0930 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2015-05-27 09:57:21 -0700 |
| commit | 83a35114d0e4583e6b0ca39502e68b6a92e2910c (patch) | |
| tree | f6a10dde40090d72e1dae2911057b3208d959415 /drivers/lguest | |
| parent | Merge branch 'overlayfs-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs (diff) | |
| download | linux-dev-83a35114d0e4583e6b0ca39502e68b6a92e2910c.tar.xz linux-dev-83a35114d0e4583e6b0ca39502e68b6a92e2910c.zip | |
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>
Diffstat (limited to 'drivers/lguest')
| -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 7dc93aa004c8..312ffd3d0017 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); } /* |