hw/block/onenand: Fix off-by-one error allowing out-of-bounds read

An off-by-one error in a switch case in onenand_read() allowed
a misbehaving guest to read off the end of a block of memory.

NB: the onenand device is used only by the "n800" and "n810"
machines, which are usable only with TCG, not KVM, so this is
not a security issue.

Reported-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20181115143535.5885-2-peter.maydell@linaro.org
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/hw/block/onenand.c b/hw/block/onenand.c
index 0cb8d7fa135fe9a6e53cc6b83737e4daaabf5aea..49ef68c9b1484293c91a425625cbba216057b9be 100644 (file)
--- a/hw/block/onenand.c
+++ b/hw/block/onenand.c
@@ -608,7 +608,7 @@ static uint64_t onenand_read(void *opaque, hwaddr addr,
     int offset = addr >> s->shift;
 
     switch (offset) {
-    case 0x0000 ... 0xc000:
+    case 0x0000 ... 0xbffe:
         return lduw_le_p(s->boot[0] + addr);
 
     case 0xf000:       /* Manufacturer ID */