Patchwork Add more boundary checking to sse3/4 parsing

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Submitter Andi Kleen
Date June 26, 2010, 10:06 p.m.
Message ID <20100626220611.GA12521@basil.fritz.box>
Download mbox | patch
Permalink /patch/57075/
State New
Headers show

Comments

Andi Kleen - June 26, 2010, 10:06 p.m.
Add more boundary checking to sse3/4 parsing

s?sse3 uses tables with only two entries per op, but it is indexed
with b1 which can contain variables upto 3. This happens when ssse3
or sse4 are used with REP* prefixes.

Add boundary checking for this case.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Aurelien Jarno - July 1, 2010, 11:56 p.m.
On Sun, Jun 27, 2010 at 12:06:11AM +0200, Andi Kleen wrote:
> Add more boundary checking to sse3/4 parsing
> 
> s?sse3 uses tables with only two entries per op, but it is indexed
> with b1 which can contain variables upto 3. This happens when ssse3
> or sse4 are used with REP* prefixes.
> 
> Add boundary checking for this case.
> 
> Signed-off-by: Andi Kleen <ak@linux.intel.com>

Thanks, applied.

> diff --git a/target-i386/translate.c b/target-i386/translate.c
> index 1336d6f..aae0374 100644
> --- a/target-i386/translate.c
> +++ b/target-i386/translate.c
> @@ -3472,6 +3472,8 @@ static void gen_sse(DisasContext *s, int b, target_ulong pc_start, int rex_r)
>          case 0x171: /* shift xmm, im */
>          case 0x172:
>          case 0x173:
> +            if (b1 >= 2)
> +	        goto illegal_op;
>              val = ldub_code(s->pc++);
>              if (is_xmm) {
>                  gen_op_movl_T0_im(val);
> @@ -3699,6 +3701,8 @@ static void gen_sse(DisasContext *s, int b, target_ulong pc_start, int rex_r)
>              rm = modrm & 7;
>              reg = ((modrm >> 3) & 7) | rex_r;
>              mod = (modrm >> 6) & 3;
> +            if (b1 >= 2)
> +                goto illegal_op;
>  
>              sse_op2 = sse_op_table6[b].op[b1];
>              if (!sse_op2)
> @@ -3798,6 +3802,8 @@ static void gen_sse(DisasContext *s, int b, target_ulong pc_start, int rex_r)
>              rm = modrm & 7;
>              reg = ((modrm >> 3) & 7) | rex_r;
>              mod = (modrm >> 6) & 3;
> +            if (b1 >= 2)
> +                goto illegal_op;
>  
>              sse_op2 = sse_op_table7[b].op[b1];
>              if (!sse_op2)
> 
>

Patch

diff --git a/target-i386/translate.c b/target-i386/translate.c
index 1336d6f..aae0374 100644
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -3472,6 +3472,8 @@  static void gen_sse(DisasContext *s, int b, target_ulong pc_start, int rex_r)
         case 0x171: /* shift xmm, im */
         case 0x172:
         case 0x173:
+            if (b1 >= 2)
+	        goto illegal_op;
             val = ldub_code(s->pc++);
             if (is_xmm) {
                 gen_op_movl_T0_im(val);
@@ -3699,6 +3701,8 @@  static void gen_sse(DisasContext *s, int b, target_ulong pc_start, int rex_r)
             rm = modrm & 7;
             reg = ((modrm >> 3) & 7) | rex_r;
             mod = (modrm >> 6) & 3;
+            if (b1 >= 2)
+                goto illegal_op;
 
             sse_op2 = sse_op_table6[b].op[b1];
             if (!sse_op2)
@@ -3798,6 +3802,8 @@  static void gen_sse(DisasContext *s, int b, target_ulong pc_start, int rex_r)
             rm = modrm & 7;
             reg = ((modrm >> 3) & 7) | rex_r;
             mod = (modrm >> 6) & 3;
+            if (b1 >= 2)
+                goto illegal_op;
 
             sse_op2 = sse_op_table7[b].op[b1];
             if (!sse_op2)