[Qemu-arm] [PATCH for-3.1 1/2] hw/block/onenand: Fix off-by-one error allowing out-of-bounds read

[Peter Maydell]

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 <address@hidden>
Suggested-by: Richard Henderson <address@hidden>
Signed-off-by: Peter Maydell <address@hidden>
---
I tweaked RTH's suggested fix to use an 0xbffe offset so
we don't overrun on an access to 0xbfff either.

 hw/block/onenand.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/block/onenand.c b/hw/block/onenand.c
index 0cb8d7fa135..49ef68c9b14 100644
--- 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 */
-- 
2.19.1