cifs client set 4 to DataLength of create_posix context, which mean Mode variable of create_posix context is only available. So buffer validation of ksmbd should check only the size of Mode except for the size of Reserved variable.
Fixes: 8f77150c15f8 ("ksmbd: add buffer validation for SMB2_CREATE_CONTEXT") Cc: stable@vger.kernel.org # v5.15+ Reported-by: Steve French smfrench@gmail.com Signed-off-by: Namjae Jeon linkinjeon@kernel.org --- fs/ksmbd/smb2pdu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 1866c81c5c99..3926ca18dca4 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -2688,7 +2688,7 @@ int smb2_open(struct ksmbd_work *work) (struct create_posix *)context; if (le16_to_cpu(context->DataOffset) + le32_to_cpu(context->DataLength) < - sizeof(struct create_posix)) { + sizeof(struct create_posix) - 4) { rc = -EINVAL; goto err_out1; }