Libguestfs - Oct 2017 - [PATCH] common/mlutils: fix f_type comparisons

statfs::f_type is usually a signed type, so cast it to unsigned to check
its value against magic values of filesystems.
---
 common/mlutils/unix_utils-c.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/common/mlutils/unix_utils-c.c b/common/mlutils/unix_utils-c.c
index f8c4f8abe..2afdc9e5f 100644
--- a/common/mlutils/unix_utils-c.c
+++ b/common/mlutils/unix_utils-c.c
@@ -357,9 +357,9 @@ guestfs_int_mllib_statvfs_is_network_filesystem (value
pathv)
 #define SMB_SUPER_MAGIC 0x517b
 #endif
 
-  return Val_bool (buf.f_type == CIFS_MAGIC_NUMBER ||
-                   buf.f_type == NFS_SUPER_MAGIC ||
-                   buf.f_type == SMB_SUPER_MAGIC);
+  return Val_bool ((unsigned int) buf.f_type == CIFS_MAGIC_NUMBER ||
+                   (unsigned int) buf.f_type == NFS_SUPER_MAGIC ||
+                   (unsigned int) buf.f_type == SMB_SUPER_MAGIC);
 #else
   return Val_bool (0);
 #endif
-- 
2.13.6

On Wed, Oct 11, 2017 at 04:37:09PM +0200, Pino Toscano
wrote:
> statfs::f_type is usually a signed type, so cast it to unsigned to check
> its value against magic values of filesystems.
> ---
>  common/mlutils/unix_utils-c.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/common/mlutils/unix_utils-c.c b/common/mlutils/unix_utils-c.c
> index f8c4f8abe..2afdc9e5f 100644
> --- a/common/mlutils/unix_utils-c.c
> +++ b/common/mlutils/unix_utils-c.c
> @@ -357,9 +357,9 @@ guestfs_int_mllib_statvfs_is_network_filesystem (value
pathv)
>  #define SMB_SUPER_MAGIC 0x517b
>  #endif
>  
> -  return Val_bool (buf.f_type == CIFS_MAGIC_NUMBER ||
> -                   buf.f_type == NFS_SUPER_MAGIC ||
> -                   buf.f_type == SMB_SUPER_MAGIC);
> +  return Val_bool ((unsigned int) buf.f_type == CIFS_MAGIC_NUMBER ||
> +                   (unsigned int) buf.f_type == NFS_SUPER_MAGIC ||
> +                   (unsigned int) buf.f_type == SMB_SUPER_MAGIC);
>  #else
>    return Val_bool (0);
>  #endif
ACK.  Can you add the commit hash that this fixes to the commit message.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
Fedora Windows cross-compiler. Compile Windows programs, test, and
build Windows installers. Over 100 libraries supported.
http://fedoraproject.org/wiki/MinGW