[PATCH 3.19 v2 1/3] x86: Fix off-by-one in the instruction decoder length checks

[Andy Lutomirski]

If next_byte + sizeof(t) == end_kaddr, then we are trying to read
exactly to the end; this should be allowed.

Fixes: 6ba48ff46f76 x86: Remove arbitrary instruction size limit in instruction decoder
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
---
 arch/x86/lib/insn.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c
index 2480978b31cc..1313ae6b478b 100644
--- a/arch/x86/lib/insn.c
+++ b/arch/x86/lib/insn.c
@@ -28,7 +28,7 @@
 
 /* Verify next sizeof(t) bytes can be on the same instruction */
 #define validate_next(t, insn, n)	\
-	((insn)->next_byte + sizeof(t) + n < (insn)->end_kaddr)
+	((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
 
 #define __get_next(t, insn)	\
 	({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); r; })
-- 
2.1.0

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