From: Juergen Gross jgross@suse.com
[ Upstream commit f1956f4ec15195ec60976d9b5625326285ab102e ]
When connecting the Xen 9pfs frontend to the backend, the "versions" Xenstore entry written by the backend is parsed in a wrong way.
The "versions" entry is defined to contain the versions supported by the backend separated by commas (e.g. "1,2"). Today only version "1" is defined. Unfortunately the frontend doesn't look for "1" being listed in the entry, but it is expecting the entry to have the value "1".
This will result in failure as soon as the backend will support e.g. versions "1" and "2".
Fix that by scanning the entry correctly.
Link: https://lkml.kernel.org/r/20230130113036.7087-2-jgross@suse.com Fixes: 71ebd71921e4 ("xen/9pfs: connect to the backend") Signed-off-by: Juergen Gross jgross@suse.com Reviewed-by: Simon Horman simon.horman@corigine.com Signed-off-by: Dominique Martinet asmadeus@codewreck.org Signed-off-by: Eric Van Hensbergen ericvh@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/9p/trans_xen.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c index 4255f2a3bea48..afa29f2a16050 100644 --- a/net/9p/trans_xen.c +++ b/net/9p/trans_xen.c @@ -399,13 +399,19 @@ static int xen_9pfs_front_probe(struct xenbus_device *dev, int ret, i; struct xenbus_transaction xbt; struct xen_9pfs_front_priv *priv = NULL; - char *versions; + char *versions, *v; unsigned int max_rings, max_ring_order, len = 0;
versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len); if (IS_ERR(versions)) return PTR_ERR(versions); - if (strcmp(versions, "1")) { + for (v = versions; *v; v++) { + if (simple_strtoul(v, &v, 10) == 1) { + v = NULL; + break; + } + } + if (v) { kfree(versions); return -EINVAL; }