[PATCH AUTOSEL 5.4 22/26] cifs: fix missing spinlock around update to ses->status
From: Sasha Levin <sashal@kernel.org>
Date: 2021-07-05 15:34:04
Also in:
linux-cifs, lkml
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
From: Steve French <redacted>
[ Upstream commit 0060a4f28a9ef45ae8163c0805e944a2b1546762 ]
In the other places where we update ses->status we protect the
updates via GlobalMid_Lock. So to be consistent add the same
locking around it in cifs_put_smb_ses where it was missing.
Addresses-Coverity: 1268904 ("Data race condition")
Signed-off-by: Steve French <redacted>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/cifs/cifsglob.h | 3 ++-
fs/cifs/connect.c | 5 ++++-
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index b16c994414ab..9c0e348cb00f 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h@@ -964,7 +964,7 @@ struct cifs_ses { struct mutex session_mutex; struct TCP_Server_Info *server; /* pointer to server info */ int ses_count; /* reference counter */ - enum statusEnum status; + enum statusEnum status; /* updates protected by GlobalMid_Lock */ unsigned overrideSecFlg; /* if non-zero override global sec flags */ char *serverOS; /* name of operating system underlying server */ char *serverNOS; /* name of network operating system of server */
@@ -1814,6 +1814,7 @@ require use of the stronger protocol */ * list operations on pending_mid_q and oplockQ * updates to XID counters, multiplex id and SMB sequence numbers * list operations on global DnotifyReqList + * updates to ses->status * tcp_ses_lock protects: * list operations on tcp and SMB session lists * tcon->open_file_lock protects the list of open files hanging off the tcon
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index ab9eeb5ff8e5..da0720f41ebc 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c@@ -3049,9 +3049,12 @@ void cifs_put_smb_ses(struct cifs_ses *ses) spin_unlock(&cifs_tcp_ses_lock); return; } + spin_unlock(&cifs_tcp_ses_lock); + + spin_lock(&GlobalMid_Lock); if (ses->status == CifsGood) ses->status = CifsExiting; - spin_unlock(&cifs_tcp_ses_lock); + spin_unlock(&GlobalMid_Lock); cifs_free_ipc(ses);
--
2.30.2