Commit 86d7bd6e authored by David Howells's avatar David Howells Committed by Jakub Kicinski
Browse files

ocfs2: Fix use of slab data with sendpage 



ocfs2 uses kzalloc() to allocate buffers for o2net_hand, o2net_keep_req and
o2net_keep_resp and then passes these to sendpage.  This isn't really
allowed as the lifetime of slab objects is not controlled by page ref -
though in this case it will probably work.  sendmsg() with MSG_SPLICE_PAGES
will, however, print a warning and give an error.

Fix it to use folio_alloc() instead to allocate a buffer for the handshake
message, keepalive request and reply messages.

Fixes: 98211489 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem")
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
cc: Mark Fasheh <mark@fasheh.com>
cc: Kurt Hackel <kurt.hackel@oracle.com>
cc: Joel Becker <jlbec@evilplan.org>
cc: Joseph Qi <joseph.qi@linux.alibaba.com>
cc: ocfs2-devel@oss.oracle.com
Link: https://lore.kernel.org/r/20230623225513.2732256-14-dhowells@redhat.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent d2fe2107

fs/ocfs2/cluster/tcp.c

+12 −11
Original line number Diff line number Diff line
@@ -2087,18 +2087,24 @@ void o2net_stop_listening(struct o2nm_node *node) 


int o2net_init(void)

{

	struct folio *folio;

	void *p;

	unsigned long i;



	o2quo_init();



	o2net_debugfs_init();



	o2net_hand = kzalloc(sizeof(struct o2net_handshake), GFP_KERNEL);

	o2net_keep_req = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);

	o2net_keep_resp = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);

	if (!o2net_hand || !o2net_keep_req || !o2net_keep_resp)

	folio = folio_alloc(GFP_KERNEL | __GFP_ZERO, 0);

	if (!folio)

		goto out;



	p = folio_address(folio);

	o2net_hand = p;

	p += sizeof(struct o2net_handshake);

	o2net_keep_req = p;

	p += sizeof(struct o2net_msg);

	o2net_keep_resp = p;



	o2net_hand->protocol_version = cpu_to_be64(O2NET_PROTOCOL_VERSION);

	o2net_hand->connector_id = cpu_to_be64(1);
@@ -2124,9 +2130,6 @@ int o2net_init(void) 
	return 0;



out:

	kfree(o2net_hand);

	kfree(o2net_keep_req);

	kfree(o2net_keep_resp);

	o2net_debugfs_exit();

	o2quo_exit();

	return -ENOMEM;
@@ -2135,8 +2138,6 @@ int o2net_init(void) 
void o2net_exit(void)

{

	o2quo_exit();

	kfree(o2net_hand);

	kfree(o2net_keep_req);

	kfree(o2net_keep_resp);

	o2net_debugfs_exit();

	folio_put(virt_to_folio(o2net_hand));

}