From 16dd9b8c31aee7ae074fa3ee36a797e9ba9f7e4f Mon Sep 17 00:00:00 2001 From: Shyam Prasad N Date: Wed, 14 Jul 2021 23:00:00 -0500 Subject: cifs: added WARN_ON for all the count decrements We have a few ref counters srv_count, ses_count and tc_count which we use for ref counting. Added a WARN_ON during the decrement of each of these counters to make sure that they don't go below their minimum values. Signed-off-by: Shyam Prasad N Signed-off-by: Steve French --- fs/cifs/connect.c | 9 +++++++++ fs/cifs/smb2ops.c | 2 ++ 2 files changed, 11 insertions(+) (limited to 'fs') diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index a1e870232114..6b6c3e341b42 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1295,6 +1295,9 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect) return; } + /* srv_count can never go negative */ + WARN_ON(server->srv_count < 0); + put_net(cifs_net_ns(server)); list_del_init(&server->tcp_ses_list); @@ -1654,6 +1657,9 @@ void cifs_put_smb_ses(struct cifs_ses *ses) } spin_unlock(&cifs_tcp_ses_lock); + /* ses_count can never go negative */ + WARN_ON(ses->ses_count < 0); + spin_lock(&GlobalMid_Lock); if (ses->status == CifsGood) ses->status = CifsExiting; @@ -2021,6 +2027,9 @@ cifs_put_tcon(struct cifs_tcon *tcon) return; } + /* tc_count can never go negative */ + WARN_ON(tcon->tc_count < 0); + if (tcon->use_witness) { int rc; diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 232d528df230..ba3c58e1f725 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -2910,6 +2910,8 @@ smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses, /* ipc tcons are not refcounted */ spin_lock(&cifs_tcp_ses_lock); tcon->tc_count--; + /* tc_count can never go negative */ + WARN_ON(tcon->tc_count < 0); spin_unlock(&cifs_tcp_ses_lock); } kfree(utf16_path); -- cgit v1.2.3