Drivers: hv: Free msginfo when the buffer fails to decrypt

The early failure path in __vmbus_establish_gpadl() doesn't deallocate
msginfo if the buffer fails to decrypt.

Fix the leak by breaking out the cleanup code into a separate function
and calling it where required.

Fixes: d4dccf353db80 ("Drivers: hv: vmbus: Mark vmbus ring buffer visible to host in Isolation VM")
Reported-by: Michael Kelley <mkhlinux@outlook.com>
Closes: https://lore.kernel.org/linux-hyperv/SN6PR02MB41573796F9787F67E0E97049D472A@SN6PR02MB4157.namprd02.prod.outlook.com
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index d69713201beffd9e62c6c7ab0b116763daf1c835..88485d255a4224b5ead4e0ef5d80b14c27ee9ecb 100644 (file)
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -410,6 +410,21 @@ static int create_gpadl_header(enum hv_gpadl_type type, void *kbuffer,
        return 0;
 }
 
+static void vmbus_free_channel_msginfo(struct vmbus_channel_msginfo *msginfo)
+{
+       struct vmbus_channel_msginfo *submsginfo, *tmp;
+
+       if (!msginfo)
+               return;
+
+       list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist,
+                                msglistentry) {
+               kfree(submsginfo);
+       }
+
+       kfree(msginfo);
+}
+
 /*
  * __vmbus_establish_gpadl - Establish a GPADL for a buffer or ringbuffer
  *
@@ -429,7 +444,7 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
        struct vmbus_channel_gpadl_header *gpadlmsg;
        struct vmbus_channel_gpadl_body *gpadl_body;
        struct vmbus_channel_msginfo *msginfo = NULL;
-       struct vmbus_channel_msginfo *submsginfo, *tmp;
+       struct vmbus_channel_msginfo *submsginfo;
        struct list_head *curr;
        u32 next_gpadl_handle;
        unsigned long flags;
@@ -459,6 +474,7 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
                        dev_warn(&channel->device_obj->device,
                                "Failed to set host visibility for new GPADL %d.\n",
                                ret);
+                       vmbus_free_channel_msginfo(msginfo);
                        return ret;
                }
        }
@@ -535,12 +551,8 @@ cleanup:
        spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
        list_del(&msginfo->msglistentry);
        spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
-       list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist,
-                                msglistentry) {
-               kfree(submsginfo);
-       }
 
-       kfree(msginfo);
+       vmbus_free_channel_msginfo(msginfo);
 
        if (ret) {
                /*