[PATCH 5.11 291/601] Drivers: hv: vmbus: Use after free in __vmbus_open()

From: Greg Kroah-Hartman
Date: Wed May 12 2021 - 13:31:07 EST


From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

[ Upstream commit 3e9bf43f7f7a46f21ec071cb47be92d0874c48da ]

The "open_info" variable is added to the &vmbus_connection.chn_msg_list,
but the error handling frees "open_info" without removing it from the
list. This will result in a use after free. First remove it from the
list, and then free it.

Fixes: 6f3d791f3006 ("Drivers: hv: vmbus: Fix rescind handling issues")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Andrea Parri <parri.andrea@xxxxxxxxx>
Link: https://lore.kernel.org/r/YHV3XLCot6xBS44r@mwanda
Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/hv/channel.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 6fb0c76bfbf8..a59ab2f3d68e 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -653,7 +653,7 @@ static int __vmbus_open(struct vmbus_channel *newchannel,

if (newchannel->rescind) {
err = -ENODEV;
- goto error_free_info;
+ goto error_clean_msglist;
}

err = vmbus_post_msg(open_msg,
--
2.30.2