2022-01-22 14:00 GMT+09:00, Steve French smfrench@gmail.com:

Looks good. I tested it and it works.

With this I can see some additional things work e.g. "stat /mnt/file" shows the correct mode bits, but the owner and group are reported as the default (0) instead of the actual uid/gid

As we discussed on chat, we need to implement code to handle Sids[] in smb311_posix_qinfo on both ksmbd and cifs.

fattr->cf_uid = cifs_sb->ctx->linux_uid; /* TODO: map uid and gid from SID */ fattr->cf_gid = cifs_sb->ctx->linux_gid;

cifs client doesn't handle Sids[] from server. Instead, cifs client seems to use uid/gid from mount option. So the uid/gid will appear as 0. And I will also change ksmbd to set uid/gid to Sid in smb311_posix_qinfo.

Thanks!

On Fri, Jan 21, 2022 at 7:47 PM Namjae Jeon linkinjeon@kernel.org wrote:

...

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;
                            }
  

-- 2.25.1

-- Thanks,

Steve