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[5.16.y,3/4] ksmbd: limits exceeding the maximum allowable outstanding requests

Message ID 20220121235427.10349-4-linkinjeon@kernel.org
State Accepted
Commit b589f5db6d4af8f14d70e31e1276b4c017668a26
Headers show
Series ksmbd stable patches for 5.16.y | expand

Commit Message

Namjae Jeon Jan. 21, 2022, 11:54 p.m. UTC 
commit b589f5db6d4af8f14d70e31e1276b4c017668a26 upstream.

If the client ignores the CreditResponse received from the server and
continues to send the request, ksmbd limits the requests if it exceeds
smb2 max credits.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
---
 fs/ksmbd/connection.c | 1 +
 fs/ksmbd/connection.h | 3 ++-
 fs/ksmbd/smb2misc.c   | 9 +++++++++
 fs/ksmbd/smb2pdu.c    | 1 +
 4 files changed, 13 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/fs/ksmbd/connection.c b/fs/ksmbd/connection.c
index 83a94d0bb480..d1d0105be5b1 100644
--- a/fs/ksmbd/connection.c
+++ b/fs/ksmbd/connection.c
@@ -62,6 +62,7 @@  struct ksmbd_conn *ksmbd_conn_alloc(void)
 	atomic_set(&conn->req_running, 0);
 	atomic_set(&conn->r_count, 0);
 	conn->total_credits = 1;
+	conn->outstanding_credits = 1;
 
 	init_waitqueue_head(&conn->req_running_q);
 	INIT_LIST_HEAD(&conn->conns_list);
diff --git a/fs/ksmbd/connection.h b/fs/ksmbd/connection.h
index 08e85568ccd6..8694aef482c1 100644
--- a/fs/ksmbd/connection.h
+++ b/fs/ksmbd/connection.h
@@ -61,7 +61,8 @@  struct ksmbd_conn {
 	atomic_t			req_running;
 	/* References which are made for this Server object*/
 	atomic_t			r_count;
-	unsigned short			total_credits;
+	unsigned int			total_credits;
+	unsigned int			outstanding_credits;
 	spinlock_t			credits_lock;
 	wait_queue_head_t		req_running_q;
 	/* Lock to protect requests list*/
diff --git a/fs/ksmbd/smb2misc.c b/fs/ksmbd/smb2misc.c
index fedcb753c7af..4a9460153b59 100644
--- a/fs/ksmbd/smb2misc.c
+++ b/fs/ksmbd/smb2misc.c
@@ -337,7 +337,16 @@  static int smb2_validate_credit_charge(struct ksmbd_conn *conn,
 			    credit_charge, conn->total_credits);
 		ret = 1;
 	}
+
+	if ((u64)conn->outstanding_credits + credit_charge > conn->vals->max_credits) {
+		ksmbd_debug(SMB, "Limits exceeding the maximum allowable outstanding requests, given : %u, pending : %u\n",
+			    credit_charge, conn->outstanding_credits);
+		ret = 1;
+	} else
+		conn->outstanding_credits += credit_charge;
+
 	spin_unlock(&conn->credits_lock);
+
 	return ret;
 }
 
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index cbeadaf20697..fcb456ef765b 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -322,6 +322,7 @@  int smb2_set_rsp_credits(struct ksmbd_work *work)
 	}
 
 	conn->total_credits -= credit_charge;
+	conn->outstanding_credits -= credit_charge;
 	credits_requested = max_t(unsigned short,
 				  le16_to_cpu(req_hdr->CreditRequest), 1);