[Linux-kernel-mentees] [PATCH v2] packet: Fix undefined behavior in bit shift

Jiunn Chang c0d1n61at3 at gmail.com
Thu Jun 27 03:25:30 UTC 2019


Shifting signed 32-bit value by 31 bits is undefined.  Changing most
significant bit to unsigned.

Changes included in v2:
  - use subsystem specific subject lines
  - CC required mailing lists

Signed-off-by: Jiunn Chang <c0d1n61at3 at gmail.com>
---
 include/uapi/linux/if_packet.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/uapi/linux/if_packet.h b/include/uapi/linux/if_packet.h
index 467b654bd4c7..3d884d68eb30 100644
--- a/include/uapi/linux/if_packet.h
+++ b/include/uapi/linux/if_packet.h
@@ -123,7 +123,7 @@ struct tpacket_auxdata {
 /* Rx and Tx ring - header status */
 #define TP_STATUS_TS_SOFTWARE		(1 << 29)
 #define TP_STATUS_TS_SYS_HARDWARE	(1 << 30) /* deprecated, never set */
-#define TP_STATUS_TS_RAW_HARDWARE	(1 << 31)
+#define TP_STATUS_TS_RAW_HARDWARE	(1U << 31)
 
 /* Rx ring - feature request bits */
 #define TP_FT_REQ_FILL_RXHASH	0x1
-- 
2.22.0



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