Messages in this thread Patch in this message | | | From | Simon Gaiser <> | Subject | [PATCH] xen: xenbus_dev_frontend: Really return response string | Date | Thu, 15 Mar 2018 04:08:03 +0100 |
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xenbus_command_reply() did not actually copy the response string and leaked stack content instead.
Fixes: 9a6161fe73bd ("xen: return xenstore command failures via response instead of rc") Signed-off-by: Simon Gaiser <simon@invisiblethingslab.com> ---
PS: AFAICS this is not a security issue since /dev/xen/xenbus is normally only accessible by root and giving xenstore access to a less trusted entity probably has a bunch of other unintended consequences.
drivers/xen/xenbus/xenbus_dev_frontend.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c index a493e99bed21..845a70fa7f79 100644 --- a/drivers/xen/xenbus/xenbus_dev_frontend.c +++ b/drivers/xen/xenbus/xenbus_dev_frontend.c @@ -403,7 +403,7 @@ static int xenbus_command_reply(struct xenbus_file_priv *u, { struct { struct xsd_sockmsg hdr; - const char body[16]; + char body[16]; } msg; int rc; @@ -412,6 +412,7 @@ static int xenbus_command_reply(struct xenbus_file_priv *u, msg.hdr.len = strlen(reply) + 1; if (msg.hdr.len > sizeof(msg.body)) return -E2BIG; + memcpy(&msg.body, reply, msg.hdr.len); mutex_lock(&u->reply_mutex); rc = queue_reply(&u->read_buffers, &msg, sizeof(msg.hdr) + msg.hdr.len); -- 2.16.2
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