[Qemu-devel] [PATCH] linux-user: check valid address in access_ok()

[Rémi Denis-Courmont]

This works around the LTP crash, but there are problably better ways to
go about it.

Signed-off-by: Rémi Denis-Courmont <address@hidden>
Cc: <address@hidden>
---
 linux-user/qemu.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index ef400cb78a..1d222a0cce 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -457,7 +457,8 @@ extern unsigned long guest_stack_size;
 
 static inline int access_ok(int type, abi_ulong addr, abi_ulong size)
 {
-    return page_check_range((target_ulong)addr, size,
+    return guest_addr_valid(addr) && guest_addr_valid(addr + size) &&
+           page_check_range((target_ulong)addr, size,
                             (type == VERIFY_READ) ? PAGE_READ : (PAGE_READ | 
PAGE_WRITE)) == 0;
 }
 
-- 
2.20.1