Merge tag 'v7.2-rc1-smb3-server-fixes' of git://git.samba.org/ksmbd

Pull smb server fixes from Steve French:

 - Fix several use-after-free races in durable handle reconnect,
   supersede, and oplock handling

 - Avoid holding the inode oplock lock while waiting for a lease break
   acknowledgement. This removes delays of up to 35 seconds when cifs.ko
   closes a deferred handle in response to a lease break

 - Fix malformed security descriptor handling, including an undersized
   DACL allocation issue and an out-of-bounds ACE SID read

 - Fix memory leaks in security descriptor and DOS attribute xattr
   encoding/decoding error paths

 - Fix outstanding SMB2 credit leaks on aborted requests and correct the
   QUERY_INFO credit charge calculation

 - Fix hard-link creation without replacement being incorrectly rejected
   when the handle lacks DELETE access

 - Avoid unnecessary zeroing of large SMB2 read buffers

 - Add an oplock list lockdep annotation and update the documented
   support status for durable handles and SMB3.1.1 compression

 - Durable handle fixes to address ownership and lifetime races during
   reconnect, session teardown, oplock handling, and superseding opens,
   preventing stale session and file references from being used by
   concurrent operations

* tag 'v7.2-rc1-smb3-server-fixes' of git://git.samba.org/ksmbd:
  ksmbd: fix app-instance durable supersede session UAF
  ksmbd: snapshot previous oplock state before durable checks
  ksmbd: close superseded durable handles through refcount handoff
  ksmbd: fix use-after-free of fp->owner.name in durable handle owner check
  smb/server: do not require delete access for non-replacing links
  ksmbd: don't hold ci->m_lock while waiting for a lease break ack
  ksmbd: doc: update feature support status for durable handles and compression
  ksmbd: annotate oplock list traversals under m_lock
  ksmbd: fix outstanding credit leak on abort and error paths
  ksmbd: fix credit charge calculation for SMB2 QUERY_INFO
  ksmbd: avoid zeroing the read buffer in smb2_read()
  ksmbd: validate num_subauth when copying ACE in set_ntacl_dacl
  ksmbd: reject undersized DACLs before parsing ACEs
  ksmbd: fix n.data memory leak in ksmbd_vfs_set_dos_attrib_xattr
  ksmbd: Fix acl.sd_buf memory leak and invalid sd_size error handling
  ksmbd: fix sd_ndr.data memory leak in ksmbd_vfs_set_sd_xattr

1 files changed, 14 insertions, 0 deletions

diff --git a/fs/smb/server/server.c b/fs/smb/server/server.c
index 36feda7e0942..36a5ea4828ad 100644
--- a/fs/smb/server/server.c
+++ b/fs/smb/server/server.c
@@ -242,6 +242,20 @@ static void __handle_ksmbd_work(struct ksmbd_work *work,
 	} while (is_chained == true);
 
 send:
+	/*
+	 * Release any credit charge still outstanding for this request.  On
+	 * the normal path smb2_set_rsp_credits() already returned it, but the
+	 * abort, error and send-no-response paths skip that call, so the
+	 * charge would otherwise leak and eventually exhaust the connection's
+	 * outstanding credit window.
+	 */
+	if (work->credit_charge) {
+		spin_lock(&conn->credits_lock);
+		conn->outstanding_credits -= work->credit_charge;
+		work->credit_charge = 0;
+		spin_unlock(&conn->credits_lock);
+	}
+
 	if (work->tcon)
 		ksmbd_tree_connect_put(work->tcon);
 	smb3_preauth_hash_rsp(work);