9p/trans_xen: replace simple_strto* with kstrtouint

In xen_9pfs_front_init(), parse the backend version list as comma-separated
tokens with kstrtouint(), keep strict token validation, and explicitly
require protocol version 1 to be present.

This replaces the deprecated simple_strtoul(), improves error reporting
consistency, and avoids partially parsed values in control paths.

Signed-off-by: Yufan Chen <ericterminal@gmail.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Message-ID: <20260324153023.86853-3-ericterminal@gmail.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>

diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
index 85b9ebfaa17a6d6a50c5631674a0a80474736060..f9fb2db7a0663c966618e55b2bbba89f0e20dcbf 100644 (file)
--- a/net/9p/trans_xen.c
+++ b/net/9p/trans_xen.c
@@ -413,23 +413,29 @@ static int xen_9pfs_front_init(struct xenbus_device *dev)
        int ret, i;
        struct xenbus_transaction xbt;
        struct xen_9pfs_front_priv *priv;
-       char *versions, *v;
-       unsigned int max_rings, max_ring_order, len = 0;
+       char *versions, *v, *token;
+       bool version_1 = false;
+       unsigned int max_rings, max_ring_order, len = 0, version;
 
        versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len);
        if (IS_ERR(versions))
                return PTR_ERR(versions);
-       for (v = versions; *v; v++) {
-               if (simple_strtoul(v, &v, 10) == 1) {
-                       v = NULL;
-                       break;
+       for (v = versions; (token = strsep(&v, ",")); ) {
+               if (!*token)
+                       continue;
+
+               ret = kstrtouint(token, 10, &version);
+               if (ret) {
+                       kfree(versions);
+                       return ret;
                }
-       }
-       if (v) {
-               kfree(versions);
-               return -EINVAL;
+               if (version == 1)
+                       version_1 = true;
        }
        kfree(versions);
+       if (!version_1)
+               return -EINVAL;
+
        max_rings = xenbus_read_unsigned(dev->otherend, "max-rings", 0);
        if (max_rings < XEN_9PFS_NUM_RINGS)
                return -EINVAL;