Thread (25 messages) 25 messages, 3 authors, 2025-09-30

RE: [PATCH hyperv-next v5 13/16] Drivers: hv: Free msginfo when the buffer fails to decrypt

From: Michael Kelley <hidden>
Date: 2025-09-09 03:14:56
Also in: linux-arch, linux-hyperv, lkml

From: Roman Kisel <redacted> Sent: Wednesday, August 27, 2025 6:06 PM
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 <redacted>
Closes: https://lore.kernel.org/linux-hyperv/SN6PR02MB41573796F9787F67E0E97049D472A@SN6PR02MB4157.namprd02.prod.outlook.com/ (local) > Signed-off-by: Roman Kisel [off-list ref]
Reviewed-by: Michael Kelley <redacted>
quoted hunk ↗ jump to hunk
---
 drivers/hv/channel.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 1621b95263a5..70270202209b 100644
--- 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 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
 	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) {
 		/*
--
2.43.0
  
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