[Xen-devel] [PATCH] xen/public: Correct the definition of GNTTAB_CACHE_SOURCE_GREF

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Discovered when running the XSA-232 PoC on a UBSAN-enabled hypervisor.

  (d79) XSA-232 PoC
  (XEN) 
================================================================================
  (XEN) UBSAN: Undefined behaviour in grant_table.c:3217:25
  (XEN) left shift of 1 by 31 places cannot be represented in type 'int'
  (XEN) ----[ Xen-4.10.0-rc  x86_64  debug=y   Tainted:    H ]----

Update all of the GNTTAB_CACHE_* constants to be unsigned integers.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
CC: Tim Deegan <tim@xxxxxxx>
CC: Wei Liu <wei.liu2@xxxxxxxxxx>
CC: Julien Grall <julien.grall@xxxxxxx>

This is a trivial bugfix, and is low risk for 4.10
---
 xen/include/public/grant_table.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/xen/include/public/grant_table.h b/xen/include/public/grant_table.h
index 018036e..180d62c 100644
--- a/xen/include/public/grant_table.h
+++ b/xen/include/public/grant_table.h
@@ -589,9 +589,9 @@ struct gnttab_cache_flush {
     } a;
     uint16_t offset; /* offset from start of grant */
     uint16_t length; /* size within the grant */
-#define GNTTAB_CACHE_CLEAN          (1<<0)
-#define GNTTAB_CACHE_INVAL          (1<<1)
-#define GNTTAB_CACHE_SOURCE_GREF    (1<<31)
+#define GNTTAB_CACHE_CLEAN          (1u<<0)
+#define GNTTAB_CACHE_INVAL          (1u<<1)
+#define GNTTAB_CACHE_SOURCE_GREF    (1u<<31)
     uint32_t op;
 };
 typedef struct gnttab_cache_flush gnttab_cache_flush_t;
-- 
2.1.4


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel