This is a note to let you know that I've just added the patch titled
vhost-vdpa: set v->config_ctx to NULL if eventfd_ctx_fdget() fails
to the 5.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
vhost-vdpa-set-v-config_ctx-to-null-if-eventfd_ctx_fdget-fails.patch
and it can be found in the queue-5.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0bde59c1723a29e294765c96dbe5c7fb639c2f96 Mon Sep 17 00:00:00 2001
From: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Date: Thu, 11 Mar 2021 14:52:57 +0100
Subject: vhost-vdpa: set v->config_ctx to NULL if eventfd_ctx_fdget() fails
From: Stefano Garzarella <sgarzare@xxxxxxxxxx>
commit 0bde59c1723a29e294765c96dbe5c7fb639c2f96 upstream.
In vhost_vdpa_set_config_call() if eventfd_ctx_fdget() fails the
'v->config_ctx' contains an error instead of a valid pointer.
Since we consider 'v->config_ctx' valid if it is not NULL, we should
set it to NULL in this case to avoid to use an invalid pointer in
other functions such as vhost_vdpa_config_put().
Fixes: 776f395004d8 ("vhost_vdpa: Support config interrupt in vdpa")
Cc: lingshan.zhu@xxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210311135257.109460-3-sgarzare@xxxxxxxxxx
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/vhost/vdpa.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -331,8 +331,12 @@ static long vhost_vdpa_set_config_call(s
if (!IS_ERR_OR_NULL(ctx))
eventfd_ctx_put(ctx);
- if (IS_ERR(v->config_ctx))
- return PTR_ERR(v->config_ctx);
+ if (IS_ERR(v->config_ctx)) {
+ long ret = PTR_ERR(v->config_ctx);
+
+ v->config_ctx = NULL;
+ return ret;
+ }
v->vdpa->config->set_config_cb(v->vdpa, &cb);
Patches currently in stable-queue which might be from sgarzare@xxxxxxxxxx are
queue-5.11/vhost-vdpa-set-v-config_ctx-to-null-if-eventfd_ctx_fdget-fails.patch
queue-5.11/vhost-vdpa-fix-use-after-free-of-v-config_ctx.patch
