[libvirt] [PATCH 1/2] apparmor: Allow access to filesystem mounts

Jamie Strandboge jamie at canonical.com
Mon Jan 27 17:38:09 UTC 2014


On 01/26/2014 03:47 PM, Felix Geyer wrote:
> Make virt-aa-helper create rules to allow VMs access to filesystem
> mounts from the host.

Note that virt-aa-helper access to various parts of the filesystem is generally
ok. However, can you be more specific about the problem you're trying to solve?
Eg, is there a bug number?

> ---
>  src/security/virt-aa-helper.c | 26 ++++++++++++++++++++------
>  1 file changed, 20 insertions(+), 6 deletions(-)
> 
> diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c
> index b9282b4..e1f7848 100644
> --- a/src/security/virt-aa-helper.c
> +++ b/src/security/virt-aa-helper.c
> @@ -578,9 +578,6 @@ valid_path(const char *path, const bool readonly)
>              return -1;
>  
>          switch (sb.st_mode & S_IFMT) {
> -            case S_IFDIR:
> -                return 1;
> -                break;
>              case S_IFSOCK:
>                  return 1;
>                  break;
> @@ -747,7 +744,7 @@ get_definition(vahControl * ctl, const char *xmlStr)
>  }
>  
>  static int
> -vah_add_file(virBufferPtr buf, const char *path, const char *perms)
> +vah_add_path(virBufferPtr buf, const char *path, const char *perms, bool recursive)
>  {
>      char *tmp = NULL;
>      int rc = -1;
> @@ -788,10 +785,14 @@ vah_add_file(virBufferPtr buf, const char *path, const char *perms)
>          goto cleanup;
>      }
>  
> -    virBufferAsprintf(buf, "  \"%s\" %s,\n", tmp, perms);
> +    virBufferAsprintf(buf, "  \"%s%s\" %s,\n", tmp, recursive ? "/**" : "", perms);
>      if (readonly) {
>          virBufferAddLit(buf, "  # don't audit writes to readonly files\n");
> -        virBufferAsprintf(buf, "  deny \"%s\" w,\n", tmp);
> +        virBufferAsprintf(buf, "  deny \"%s%s\" w,\n", tmp, recursive ? "/**" : "");
> +    }
> +    if (recursive) {
> +        // allow reading (but not creating) the dir
> +        virBufferAsprintf(buf, "  \"%s/\" r,\n", tmp);
>      }
>  
>    cleanup:
> @@ -801,6 +802,12 @@ vah_add_file(virBufferPtr buf, const char *path, const char *perms)
>  }
>  
>  static int
> +vah_add_file(virBufferPtr buf, const char *path, const char *perms)
> +{
> +    return vah_add_path(buf, path, perms, false);
> +}
> +
> +static int
>  vah_add_file_chardev(virBufferPtr buf,
>                       const char *path,
>                       const char *perms,
> @@ -1049,6 +1056,13 @@ get_files(vahControl * ctl)
>              } /* switch */
>          }
>  
> +    for (i = 0; i < ctl->def->nfss; i++) {
> +        virDomainFSDefPtr fs = ctl->def->fss[i];
> +
> +        if (vah_add_path(&buf, fs->src, fs->readonly ? "r" : "rw", true) != 0)
> +            goto cleanup;
> +    }
> +
>      if (ctl->newfile)
>          if (vah_add_file(&buf, ctl->newfile, "rw") != 0)
>              goto cleanup;
> 


-- 
Jamie Strandboge                 http://www.ubuntu.com/




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