[Qemu-devel] [PATCH] target-cris/translate.c: fix out of bounds read

[Qemu-devel] [PATCH] target-cris/translate.c: fix out of bounds read

[zhanghailiang]

In function t_gen_mov_TN_preg and t_gen_mov_preg_TN, The begin check about the
validity of in-parameter 'r' is useless. We still access cpu_PR[r] in the
follow code if it is invalid. Which will be an out-of-bounds read error.

Fix it by using assert() to ensure it is valid before using it.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
---
 target-cris/translate.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/target-cris/translate.c b/target-cris/translate.c
index e37b04e..76406af 100644
--- a/target-cris/translate.c
+++ b/target-cris/translate.c
@@ -169,9 +169,7 @@ static int preg_sizes[] = {
 
 static inline void t_gen_mov_TN_preg(TCGv tn, int r)
 {
-    if (r < 0 || r > 15) {
-        fprintf(stderr, "wrong register read $p%d\n", r);
-    }
+    assert(r >= 0 && r <= 15);
     if (r == PR_BZ || r == PR_WZ || r == PR_DZ) {
         tcg_gen_mov_tl(tn, tcg_const_tl(0));
     } else if (r == PR_VR) {
@@ -182,9 +180,7 @@ static inline void t_gen_mov_TN_preg(TCGv tn, int r)
 }
 static inline void t_gen_mov_preg_TN(DisasContext *dc, int r, TCGv tn)
 {
-    if (r < 0 || r > 15) {
-        fprintf(stderr, "wrong register write $p%d\n", r);
-    }
+    assert(r >= 0 && r <= 15);
     if (r == PR_BZ || r == PR_WZ || r == PR_DZ) {
         return;
     } else if (r == PR_SRS) {
-- 
1.7.12.4

Re: [Qemu-devel] [PATCH] target-cris/translate.c: fix out of bounds read

[Paolo Bonzini]

On 17/11/2014 06:57, zhanghailiang wrote:
> In function t_gen_mov_TN_preg and t_gen_mov_preg_TN, The begin check about the
> validity of in-parameter 'r' is useless. We still access cpu_PR[r] in the
> follow code if it is invalid. Which will be an out-of-bounds read error.
> 
> Fix it by using assert() to ensure it is valid before using it.
> 
> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> ---
>  target-cris/translate.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/target-cris/translate.c b/target-cris/translate.c
> index e37b04e..76406af 100644
> --- a/target-cris/translate.c
> +++ b/target-cris/translate.c
> @@ -169,9 +169,7 @@ static int preg_sizes[] = {
>  
>  static inline void t_gen_mov_TN_preg(TCGv tn, int r)
>  {
> -    if (r < 0 || r > 15) {
> -        fprintf(stderr, "wrong register read $p%d\n", r);
> -    }
> +    assert(r >= 0 && r <= 15);
>      if (r == PR_BZ || r == PR_WZ || r == PR_DZ) {
>          tcg_gen_mov_tl(tn, tcg_const_tl(0));
>      } else if (r == PR_VR) {
> @@ -182,9 +180,7 @@ static inline void t_gen_mov_TN_preg(TCGv tn, int r)
>  }
>  static inline void t_gen_mov_preg_TN(DisasContext *dc, int r, TCGv tn)
>  {
> -    if (r < 0 || r > 15) {
> -        fprintf(stderr, "wrong register write $p%d\n", r);
> -    }
> +    assert(r >= 0 && r <= 15);
>      if (r == PR_BZ || r == PR_WZ || r == PR_DZ) {
>          return;
>      } else if (r == PR_SRS) {
> 

Applied, thanks.

Paolo