From 2ae23f0ecf002203977b7337219e2413abd656ec Mon Sep 17 00:00:00 2001 From: Paul Durrant Date: Fri, 15 Feb 2019 16:25:33 +0000 Subject: [PATCH] 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: Peter Maydell Signed-off-by: Paul Durrant Acked-by: Anthony PERARD Message-Id: <20190215162533.19475-4-paul.durrant@citrix.com> Signed-off-by: Anthony PERARD --- hw/block/xen-block.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c index 29afe2703a..37a456c207 100644 --- a/hw/block/xen-block.c +++ b/hw/block/xen-block.c @@ -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') {