Commit a6853b9c authored Jun 20, 2019 by David Howells

afs: Fix vlserver record corruption



Because I made the afs_call struct share pointers to an afs_server object
and an afs_vlserver object to save space, afs_put_call() calls
afs_put_server() on afs_vlserver object (which is only meant for the
afs_server object) because it sees that call->server isn't NULL.

This means that the afs_vlserver object gets unpredictably and randomly
modified, depending on what config options are set (such as lockdep).

Fix this by getting rid of the union and having two non-overlapping
pointers in the afs_call struct.

Fixes: ffba718e ("afs: Get rid of afs_call::reply[]")
Signed-off-by: David Howells <dhowells@redhat.com>

parent 3647e42b

fs/afs/internal.h

+2 −4

Original line number	Diff line number	Diff line
		@@ -113,10 +113,8 @@ struct afs_call {
		struct rxrpc_call rxcall; / RxRPC call handle */
		struct key key; / security for this call */
		struct afs_net net; / The network namespace */
		union {
		struct afs_server *server;
		struct afs_vlserver *vlserver;
		};
		struct afs_server server; / The fileserver record if fs op (pins ref) */
		struct afs_vlserver vlserver; / The vlserver record if vl op */
		struct afs_cb_interest cbi; / Callback interest for server used */
		struct afs_vnode lvnode; / vnode being locked */
		void request; / request data (first part) */