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From 8861fd5180476f45f9e8853db154600469a0284f Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@microsoft.com>
Date: Thu, 25 Apr 2024 12:49:50 -0500
Subject: smb3: fix lock ordering potential deadlock in cifs_sync_mid_result

From: Steve French <stfrench@microsoft.com>

commit 8861fd5180476f45f9e8853db154600469a0284f upstream.

Coverity spotted that the cifs_sync_mid_result function could deadlock

"Thread deadlock (ORDER_REVERSAL) lock_order: Calling spin_lock acquires
lock TCP_Server_Info.srv_lock while holding lock TCP_Server_Info.mid_lock"

Addresses-Coverity: 1590401 ("Thread deadlock (ORDER_REVERSAL)")
Cc: stable@vger.kernel.org
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/client/transport.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/fs/smb/client/transport.c
+++ b/fs/smb/client/transport.c
@@ -909,12 +909,15 @@ cifs_sync_mid_result(struct mid_q_entry
 			list_del_init(&mid->qhead);
 			mid->mid_flags |= MID_DELETED;
 		}
+		spin_unlock(&server->mid_lock);
 		cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
 			 __func__, mid->mid, mid->mid_state);
 		rc = -EIO;
+		goto sync_mid_done;
 	}
 	spin_unlock(&server->mid_lock);
 
+sync_mid_done:
 	release_mid(mid);
 	return rc;
 }