Commit 2ae23f0e authored by Paul Durrant's avatar Paul Durrant Committed by Anthony PERARD
Browse files

xen-block: report error condition from vbd_name_to_disk() 



The function needs to make sure it is passed a valid disk name. This is
easily done by making sure that the parsing loop results in a non-zero
value.

Spotted by Coverity: CID 1398640

Reported-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarPaul Durrant <paul.durrant@citrix.com>
Acked-by: default avatarAnthony PERARD <anthony.perard@citrix.com>
Message-Id: <20190215162533.19475-4-paul.durrant@citrix.com>
Signed-off-by: default avatarAnthony PERARD <anthony.perard@citrix.com>
parent 210b9776

hw/block/xen-block.c

+15 −6
Original line number Diff line number Diff line
@@ -351,21 +351,28 @@ static void xen_block_get_vdev(Object *obj, Visitor *v, const char *name, 
    g_free(str);

}



static unsigned int vbd_name_to_disk(const char *name, const char **endp)

static int vbd_name_to_disk(const char *name, const char **endp,

                            unsigned long *disk)

{

    unsigned int disk = 0;

    unsigned int n = 0;



    while (*name != '\0') {

        if (!g_ascii_isalpha(*name) || !g_ascii_islower(*name)) {

            break;

        }



        disk *= 26;

        disk += *name++ - 'a' + 1;

        n *= 26;

        n += *name++ - 'a' + 1;

    }

    *endp = name;



    return disk - 1;

    if (!n) {

        return -1;

    }



    *disk = n - 1;



    return 0;

}



static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name,
@@ -418,7 +425,9 @@ static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name, 
            }

        }

    } else {

        vdev->disk = vbd_name_to_disk(p, &end);

        if (vbd_name_to_disk(p, &end, &vdev->disk)) {

            goto invalid;

        }

    }



    if (*end != '\0') {