Commit 39a154fc authored by Paulo Alcantara's avatar Paulo Alcantara Committed by Steve French
Browse files

cifs: protect access of TCP_Server_Info::{dstaddr,hostname} 



Use the appropriate locks to protect access of hostname and dstaddr
fields in cifs_tree_connect() as they might get changed by other
tasks.

Signed-off-by: default avatarPaulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: default avatarEnzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 775e44d6

fs/cifs/dfs.c

+11 −11
Original line number Diff line number Diff line
@@ -327,8 +327,8 @@ static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb 
	return rc;

}



static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host,

				       size_t tcp_host_len, char *share, bool *target_match)

static int target_share_matches_server(struct TCP_Server_Info *server, char *share,

				       bool *target_match)

{

	int rc = 0;

	const char *dfs_host;
@@ -338,13 +338,16 @@ static int target_share_matches_server(struct TCP_Server_Info *server, const cha 
	extract_unc_hostname(share, &dfs_host, &dfs_host_len);



	/* Check if hostnames or addresses match */

	if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {

		cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,

			 dfs_host, (int)tcp_host_len, tcp_host);

	cifs_server_lock(server);

	if (dfs_host_len != strlen(server->hostname) ||

	    strncasecmp(dfs_host, server->hostname, dfs_host_len)) {

		cifs_dbg(FYI, "%s: %.*s doesn't match %s\n", __func__,

			 (int)dfs_host_len, dfs_host, server->hostname);

		rc = match_target_ip(server, dfs_host, dfs_host_len, target_match);

		if (rc)

			cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);

	}

	cifs_server_unlock(server);

	return rc;

}
@@ -358,13 +361,9 @@ static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *t 
	struct cifs_ses *root_ses = CIFS_DFS_ROOT_SES(tcon->ses);

	struct cifs_tcon *ipc = root_ses->tcon_ipc;

	char *share = NULL, *prefix = NULL;

	const char *tcp_host;

	size_t tcp_host_len;

	struct dfs_cache_tgt_iterator *tit;

	bool target_match;



	extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);



	tit = dfs_cache_get_tgt_iterator(tl);

	if (!tit) {

		rc = -ENOENT;
@@ -387,8 +386,7 @@ static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *t 
			break;

		}



		rc = target_share_matches_server(server, tcp_host, tcp_host_len, share,

						 &target_match);

		rc = target_share_matches_server(server, share, &target_match);

		if (rc)

			break;

		if (!target_match) {
@@ -497,7 +495,9 @@ int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const stru 
	}



	if (tcon->ipc) {

		cifs_server_lock(server);

		scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);

		cifs_server_unlock(server);

		rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);

		goto out;

	}

fs/cifs/misc.c

+2 −0
Original line number Diff line number Diff line
@@ -1277,7 +1277,9 @@ int match_target_ip(struct TCP_Server_Info *server, 
	if (rc < 0)

		return rc;



	spin_lock(&server->srv_lock);

	*result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss);

	spin_unlock(&server->srv_lock);

	cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result);

	return 0;

}