[PATCH 5.17 720/772] ksmbd: fix outstanding credits related bugs

Greg Kroah-Hartman
2022-06-07T21:46:51Z

From: Hyunchul Lee <hyc.lee@gmail.com>

commit 376b9133826865568167b4091ef92a68c4622b87 upstream.

outstanding credits must be initialized to 0,
because it means the sum of credits consumed by
in-flight requests.
And outstanding credits must be compared with
total credits in smb2_validate_credit_charge(),
because total credits are the sum of credits
granted by ksmbd.

This patch fix the following error,
while frametest with Windows clients:

Limits exceeding the maximum allowable outstanding requests,
given : 128, pending : 8065

Fixes: b589f5db6d4a ("ksmbd: limits exceeding the maximum allowable outstanding requests")
Cc: stable@vger.kernel.org
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Reported-by: Yufan Chen <wiz.chen@gmail.com>
Tested-by: Yufan Chen <wiz.chen@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ksmbd/connection.c | 2 +-
fs/ksmbd/smb2misc.c | 2 +-
fs/ksmbd/smb_common.c | 4 +++-
3 files changed, 5 insertions(+), 3 deletions(-)

--- a/fs/ksmbd/connection.c
+++ b/fs/ksmbd/connection.c
@@ -62,7 +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;
+ conn->outstanding_credits = 0;

init_waitqueue_head(&conn->req_running_q);
INIT_LIST_HEAD(&conn->conns_list);
--- a/fs/ksmbd/smb2misc.c
+++ b/fs/ksmbd/smb2misc.c
@@ -338,7 +338,7 @@ static int smb2_validate_credit_charge(s
ret = 1;
}

- if ((u64)conn->outstanding_credits + credit_charge > conn->vals->max_credits) {
+ if ((u64)conn->outstanding_credits + credit_charge > conn->total_credits) {
ksmbd_debug(SMB, "Limits exceeding the maximum allowable outstanding requests, given : %u, pending : %u\n",
credit_charge, conn->outstanding_credits);
ret = 1;
--- a/fs/ksmbd/smb_common.c
+++ b/fs/ksmbd/smb_common.c
@@ -140,8 +140,10 @@ int ksmbd_verify_smb_message(struct ksmb

hdr = work->request_buf;
if (*(__le32 *)hdr->Protocol == SMB1_PROTO_NUMBER &&
- hdr->Command == SMB_COM_NEGOTIATE)
+ hdr->Command == SMB_COM_NEGOTIATE) {
+ work->conn->outstanding_credits++;
return 0;
+ }

return -EINVAL;
}