Merge tag '6.5-rc-smb3-client-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6

Pull smb client updates from Steve French:

 - Deferred close fix

 - Debugging improvements: display missing mount option, dump rc on
   invalidate inode failures, print client_guid in DebugData, log
   session id when matching session not found in reconnect, new dynamic
   tracepoint for session not found

 - Mount fixes including: potential null dereference, and possible
   memory leak and path name parsing when double slashes

 - Fix potential use after free in compounding

 - Two crediting (flow control) fixes: fix for crediting leak (stress
   scenario with excess lease credits) and better locking around
   updating credits

 - Three cleanups from issues pointed out by the kernel test robot

 - Session state check improvements (including for potential use after
   free)

 - DFS fixes: Fix for getattr on link when DFS disabled, fix for DFS
   mounts to same share with different prefix paths, DFS mount error
   checking improvement

* tag '6.5-rc-smb3-client-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: new dynamic tracepoint to track ses not found errors
  cifs: log session id when a matching ses is not found
  smb: client: improve DFS mount check
  smb: client: fix shared DFS root mounts with different prefixes
  smb: client: fix parsing of source mount option
  smb: client: fix broken file attrs with nodfs mounts
  cifs: print client_guid in DebugData
  cifs: fix session state check in smb2_find_smb_ses
  cifs: fix session state check in reconnect to avoid use-after-free issue
  cifs: do all necessary checks for credits within or before locking
  cifs: prevent use-after-free by freeing the cfile later
  smb: client: fix warning in generic_ip_connect()
  smb: client: fix warning in CIFSFindNext()
  smb: client: fix warning in CIFSFindFirst()
  smb3: do not reserve too many oplock credits
  cifs: print more detail when invalidate_inode_mapping fails
  smb: client: fix warning in cifs_smb3_do_mount()
  smb: client: fix warning in cifs_match_super()
  cifs: print nosharesock value while dumping mount options
  SMB3: Do not send lease break acknowledgment if all file handles have been closed

1 files changed, 5 insertions, 3 deletions

diff --git a/fs/smb/client/dfs_cache.c b/fs/smb/client/dfs_cache.c
index 1513b2709889..33adf43a01f1 100644
--- a/fs/smb/client/dfs_cache.c
+++ b/fs/smb/client/dfs_cache.c
@@ -1248,18 +1248,20 @@ static int refresh_tcon(struct cifs_tcon *tcon, bool force_refresh)
 int dfs_cache_remount_fs(struct cifs_sb_info *cifs_sb)
 {
 	struct cifs_tcon *tcon;
-	struct TCP_Server_Info *server;
 
 	if (!cifs_sb || !cifs_sb->master_tlink)
 		return -EINVAL;
 
 	tcon = cifs_sb_master_tcon(cifs_sb);
-	server = tcon->ses->server;
 
-	if (!server->origin_fullpath) {
+	spin_lock(&tcon->tc_lock);
+	if (!tcon->origin_fullpath) {
+		spin_unlock(&tcon->tc_lock);
 		cifs_dbg(FYI, "%s: not a dfs mount\n", __func__);
 		return 0;
 	}
+	spin_unlock(&tcon->tc_lock);
+
 	/*
 	 * After reconnecting to a different server, unique ids won't match anymore, so we disable
 	 * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).