From b867838e927232fc37f35b753f03ba888ef14fc5 Mon Sep 17 00:00:00 2001
From: Harshvardhan Jha <harshvardhan.jha@oracle.com>
Date: Tue, 27 Jul 2021 05:37:10 +0530
Subject: [PATCH] 9p/xen: Fix end of loop tests for list_for_each_entry
Git-commit: 732b33d0dbf17e9483f0b50385bf606f724f50a2
Patch-mainline: v5.15-rc1
References: stable-5.14.6
commit 732b33d0dbf17e9483f0b50385bf606f724f50a2 upstream.
This patch addresses the following problems:
- priv can never be NULL, so this part of the check is useless
- if the loop ran through the whole list, priv->client is invalid and
it is more appropriate and sufficient to check for the end of
list_for_each_entry loop condition.
Link: http://lkml.kernel.org/r/20210727000709.225032-1-harshvardhan.jha@oracle.com
Signed-off-by: Harshvardhan Jha <harshvardhan.jha@oracle.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
net/9p/trans_xen.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
index f4fea28e05da..3ec1a51a6944 100644
--- a/net/9p/trans_xen.c
+++ b/net/9p/trans_xen.c
@@ -138,7 +138,7 @@ static bool p9_xen_write_todo(struct xen_9pfs_dataring *ring, RING_IDX size)
static int p9_xen_request(struct p9_client *client, struct p9_req_t *p9_req)
{
- struct xen_9pfs_front_priv *priv = NULL;
+ struct xen_9pfs_front_priv *priv;
RING_IDX cons, prod, masked_cons, masked_prod;
unsigned long flags;
u32 size = p9_req->tc.size;
@@ -151,7 +151,7 @@ static int p9_xen_request(struct p9_client *client, struct p9_req_t *p9_req)
break;
}
read_unlock(&xen_9pfs_lock);
- if (!priv || priv->client != client)
+ if (list_entry_is_head(priv, &xen_9pfs_devs, list))
return -EINVAL;
num = p9_req->tc.tag % priv->num_rings;
--
2.26.2