[ciqlts9_2] CVE-2025-38527

fs/cifs/cifsglob.h

@@ -422,8 +422,8 @@ struct smb_version_operations {
 	/* check for STATUS_NETWORK_SESSION_EXPIRED */
 	bool (*is_session_expired)(char *);
 	/* send oplock break response */
-	int (*oplock_response)(struct cifs_tcon *, struct cifs_fid *,
-			       struct cifsInodeInfo *);
+	int (*oplock_response)(struct cifs_tcon *tcon, __u64 persistent_fid, __u64 volatile_fid,
+			__u16 net_fid, struct cifsInodeInfo *cifs_inode);
 	/* query remote filesystem */
 	int (*queryfs)(const unsigned int, struct cifs_tcon *,
 		       struct cifs_sb_info *, struct kstatfs *);

fs/cifs/file.c

@@ -5048,17 +5048,32 @@ void cifs_oplock_break(struct work_struct *work)
 	struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo,
 						  oplock_break);
 	struct inode *inode = d_inode(cfile->dentry);
+	struct super_block *sb = inode->i_sb;
+	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 	struct cifsInodeInfo *cinode = CIFS_I(inode);
-	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
-	struct TCP_Server_Info *server = tcon->ses->server;
+	struct cifs_tcon *tcon;
+	struct TCP_Server_Info *server;
+	struct tcon_link *tlink;
 	int rc = 0;
-	bool purge_cache = false;
-	bool is_deferred = false;
-	struct cifs_deferred_close *dclose;
+	bool purge_cache = false, oplock_break_cancelled;
+	__u64 persistent_fid, volatile_fid;
+	__u16 net_fid;
 
+	/*
+	 * Hold a reference to the superblock to prevent it and its inodes from
+	 * being freed while we are accessing cinode. Otherwise, _cifsFileInfo_put()
+	 * may release the last reference to the sb and trigger inode eviction.
+	 */
+	cifs_sb_active(sb);
 	wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS,
 			TASK_UNINTERRUPTIBLE);
 
+	tlink = cifs_sb_tlink(cifs_sb);
+	if (IS_ERR(tlink))
+		goto out;
+	tcon = tlink_tcon(tlink);
+	server = tcon->ses->server;
+
 	server->ops->downgrade_oplock(server, cinode, cfile->oplock_level,
 				      cfile->oplock_epoch, &purge_cache);
 
@@ -5095,31 +5110,34 @@ void cifs_oplock_break(struct work_struct *work)
 	 * file handles but cached, then schedule deferred close immediately.
 	 * So, new open will not use cached handle.
 	 */
-	spin_lock(&CIFS_I(inode)->deferred_lock);
-	is_deferred = cifs_is_deferred_close(cfile, &dclose);
-	spin_unlock(&CIFS_I(inode)->deferred_lock);
-	if (is_deferred &&
-	    cfile->deferred_close_scheduled &&
-	    delayed_work_pending(&cfile->deferred)) {
-		if (cancel_delayed_work(&cfile->deferred)) {
-			_cifsFileInfo_put(cfile, false, false);
-			goto oplock_break_done;
-		}
-	}
+
+	if (!CIFS_CACHE_HANDLE(cinode) && !list_empty(&cinode->deferred_closes))
+		cifs_close_deferred_file(cinode);
+
+	persistent_fid = cfile->fid.persistent_fid;
+	volatile_fid = cfile->fid.volatile_fid;
+	net_fid = cfile->fid.netfid;
+	oplock_break_cancelled = cfile->oplock_break_cancelled;
+
+	_cifsFileInfo_put(cfile, false /* do not wait for ourself */, false);
 	/*
-	 * releasing stale oplock after recent reconnect of smb session using
-	 * a now incorrect file handle is not a data integrity issue but do
-	 * not bother sending an oplock release if session to server still is
-	 * disconnected since oplock already released by the server
+	 * MS-SMB2 3.2.5.19.1 and 3.2.5.19.2 (and MS-CIFS 3.2.5.42) do not require
+	 * an acknowledgment to be sent when the file has already been closed.
 	 */
-	if (!cfile->oplock_break_cancelled) {
-		rc = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
-							     cinode);
+	spin_lock(&cinode->open_file_lock);
+	/* check list empty since can race with kill_sb calling tree disconnect */
+	if (!oplock_break_cancelled && !list_empty(&cinode->openFileList)) {
+		spin_unlock(&cinode->open_file_lock);
+		rc = server->ops->oplock_response(tcon, persistent_fid,
+						  volatile_fid, net_fid, cinode);
 		cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
-	}
-oplock_break_done:
-	_cifsFileInfo_put(cfile, false /* do not wait for ourself */, false);
+	} else
+		spin_unlock(&cinode->open_file_lock);
+
+	cifs_put_tlink(tlink);
+out:
 	cifs_done_oplock_break(cinode);
+	cifs_sb_deactive(sb);
 }
 
 /*

fs/cifs/misc.c

@@ -752,7 +752,7 @@ cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode)
 	spin_unlock(&cifs_inode->open_file_lock);
 
 	list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
-		_cifsFileInfo_put(tmp_list->cfile, true, false);
+		_cifsFileInfo_put(tmp_list->cfile, false, false);
 		list_del(&tmp_list->list);
 		kfree(tmp_list);
 	}

fs/cifs/smb1ops.c

@@ -872,12 +872,11 @@ cifs_close_dir(const unsigned int xid, struct cifs_tcon *tcon,
 }
 
 static int
-cifs_oplock_response(struct cifs_tcon *tcon, struct cifs_fid *fid,
-		     struct cifsInodeInfo *cinode)
+cifs_oplock_response(struct cifs_tcon *tcon, __u64 persistent_fid,
+		__u64 volatile_fid, __u16 net_fid, struct cifsInodeInfo *cinode)
 {
-	return CIFSSMBLock(0, tcon, fid->netfid, current->tgid, 0, 0, 0, 0,
-			   LOCKING_ANDX_OPLOCK_RELEASE, false,
-			   CIFS_CACHE_READ(cinode) ? 1 : 0);
+	return CIFSSMBLock(0, tcon, net_fid, current->tgid, 0, 0, 0, 0,
+			   LOCKING_ANDX_OPLOCK_RELEASE, false, CIFS_CACHE_READ(cinode) ? 1 : 0);
 }
 
 static int

fs/cifs/smb2ops.c

@@ -2309,15 +2309,14 @@ smb2_is_network_name_deleted(char *buf, struct TCP_Server_Info *server)
 }
 
 static int
-smb2_oplock_response(struct cifs_tcon *tcon, struct cifs_fid *fid,
-		     struct cifsInodeInfo *cinode)
+smb2_oplock_response(struct cifs_tcon *tcon, __u64 persistent_fid,
+		__u64 volatile_fid, __u16 net_fid, struct cifsInodeInfo *cinode)
 {
 	if (tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LEASING)
 		return SMB2_lease_break(0, tcon, cinode->lease_key,
 					smb2_get_lease_state(cinode));
 
-	return SMB2_oplock_break(0, tcon, fid->persistent_fid,
-				 fid->volatile_fid,
+	return SMB2_oplock_break(0, tcon, persistent_fid, volatile_fid,
 				 CIFS_CACHE_READ(cinode) ? 1 : 0);
 }