Re: [Qemu-stable] [PATCH] acl: acl_add can't insert before last list element, fix

[Markus Armbruster]

Ping re 1.5.3

Markus Armbruster <address@hidden> writes:

> Watch this:
>
>     $ upstream-qemu -nodefaults -S -vnc :0,acl,sasl -monitor stdio
>     QEMU 1.5.50 monitor - type 'help' for more information
>     (qemu) acl_add vnc.username drei allow
>     acl: added rule at position 1
>     (qemu) acl_show vnc.username
>     policy: deny
>     1: allow drei
>     (qemu) acl_add vnc.username zwei allow 1
>     acl: added rule at position 2
>     (qemu) acl_show vnc.username
>     policy: deny
>     1: allow drei
>     2: allow zwei
>     (qemu) acl_add vnc.username eins allow 1
>     acl: added rule at position 1
>     (qemu) acl_show vnc.username
>     policy: deny
>     1: allow eins
>     2: allow drei
>     3: allow zwei
>
> The second acl_add inserts at position 2 instead of 1.
>
> Root cause is an off-by-one in qemu_acl_insert(): when index ==
> acl->nentries, it appends instead of inserting before the last list
> element.
>
> Cc: address@hidden
> Signed-off-by: Markus Armbruster <address@hidden>
> ---
>  util/acl.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/util/acl.c b/util/acl.c
> index a7f33ff..938b7ae 100644
> --- a/util/acl.c
> +++ b/util/acl.c
> @@ -138,9 +138,9 @@ int qemu_acl_insert(qemu_acl *acl,
>  
>      if (index <= 0)
>          return -1;
> -    if (index >= acl->nentries)
> +    if (index > acl->nentries) {
>          return qemu_acl_append(acl, deny, match);
> -
> +    }
>  
>      entry = g_malloc(sizeof(*entry));
>      entry->match = g_strdup(match);