[v2] contrib/elf2dmp: Improve robustness

[PATCH v2 08/13] contrib/elf2dmp: Use lduw_le_p() to read PDB

Posted by Akihiko Odaki 8 months, 3 weeks ago

This resolved UBSan warnings.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
---
 contrib/elf2dmp/pdb.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/contrib/elf2dmp/pdb.c b/contrib/elf2dmp/pdb.c
index 1c5051425185..492aca4434c8 100644
--- a/contrib/elf2dmp/pdb.c
+++ b/contrib/elf2dmp/pdb.c
@@ -19,6 +19,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/bswap.h"
 
 #include "pdb.h"
 #include "err.h"
@@ -186,7 +187,7 @@ static bool pdb_init_symbols(struct pdb_reader *r)
 
     r->symbols = symbols;
 
-    r->segments = *(uint16_t *)((const char *)symbols + sizeof(PDB_SYMBOLS) +
+    r->segments = lduw_le_p((const char *)symbols + sizeof(PDB_SYMBOLS) +
             symbols->module_size + symbols->offset_size +
             symbols->hash_size + symbols->srcmodule_size +
             symbols->pdbimport_size + symbols->unknown2_size +

-- 
2.44.0

Re: [PATCH v2 08/13] contrib/elf2dmp: Use lduw_le_p() to read PDB

Posted by Peter Maydell 8 months, 3 weeks ago

On Tue, 5 Mar 2024 at 07:36, Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>
> This resolved UBSan warnings.
>
> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> ---
>  contrib/elf2dmp/pdb.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/contrib/elf2dmp/pdb.c b/contrib/elf2dmp/pdb.c
> index 1c5051425185..492aca4434c8 100644
> --- a/contrib/elf2dmp/pdb.c
> +++ b/contrib/elf2dmp/pdb.c
> @@ -19,6 +19,7 @@
>   */
>
>  #include "qemu/osdep.h"
> +#include "qemu/bswap.h"
>
>  #include "pdb.h"
>  #include "err.h"
> @@ -186,7 +187,7 @@ static bool pdb_init_symbols(struct pdb_reader *r)
>
>      r->symbols = symbols;
>
> -    r->segments = *(uint16_t *)((const char *)symbols + sizeof(PDB_SYMBOLS) +
> +    r->segments = lduw_le_p((const char *)symbols + sizeof(PDB_SYMBOLS) +
>              symbols->module_size + symbols->offset_size +
>              symbols->hash_size + symbols->srcmodule_size +
>              symbols->pdbimport_size + symbols->unknown2_size +

Same comment still applies as on v1 version of this patch.

thanks
-- PMM