From: Al Viro <viro@zeniv.linux.org.uk>
To: Atul Gupta <atul.gupta@chelsio.com>
Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH] almost certain bug in drivers/crypto/chelsio/chcr_algo.c:create_authenc_wr()
Date: Sat, 15 Feb 2020 06:29:30 +0000 [thread overview]
Message-ID: <20200215062930.GA23230@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20200215061416.GZ23230@ZenIV.linux.org.uk>
Another fairly bug in there (this time in
drivers/crypto/chelsio/chtls/chtls_io.c):
/* Read TLS header to find content type and data length */
static int tls_header_read(struct tls_hdr *thdr, struct iov_iter *from)
{
if (copy_from_iter(thdr, sizeof(*thdr), from) != sizeof(*thdr))
return -EFAULT;
return (__force int)cpu_to_be16(thdr->length);
}
For one thing, that kind of force-casts is pretty much always wrong.
This one clearly says "should've used be16_to_cpu()". And that includes
annotating tls_hdr ->length as __be16; no idea about the other field
in there (->version, that is).
For another, the only caller is
recordsz = tls_header_read(&hdr, &msg->msg_iter);
size -= TLS_HEADER_LENGTH;
copied += TLS_HEADER_LENGTH;
csk->tlshws.txleft = recordsz;
csk->tlshws.type = hdr.type;
if (skb)
ULP_SKB_CB(skb)->ulp.tls.type = hdr.type;
which doesn't look like something that'll work if you get -EFAULT out of
that function. If anything, that smells like we want
recordsz = tls_header_read(&hdr, &msg->msg_iter);
if (recordsz < 0)
goto do_fault;
...
What's more, we do *not* want a header that has faulted halfway through
to be consumed. IOW, we want copy_from_iter_full():
static int tls_header_read(struct tls_hdr *thdr, struct iov_iter *from)
{
if (!copy_from_iter_full(thdr, sizeof(*thdr), from))
return -EFAULT;
return be16_to_cpu(thdr->length);
}
in addition to that missing check in the caller...
next prev parent reply other threads:[~2020-02-15 6:29 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-15 6:14 [RFC][PATCH] almost certain bug in drivers/crypto/chelsio/chcr_algo.c:create_authenc_wr() Al Viro
2020-02-15 6:29 ` Al Viro [this message]
[not found] ` <CAEopUdxRUoMo+uGgiFLWz8NsM1eL7CnkV7gY5PypxrG_nzhNWw@mail.gmail.com>
2020-02-21 5:17 ` Ayush Sawal
2020-02-22 1:44 ` Herbert Xu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200215062930.GA23230@ZenIV.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=atul.gupta@chelsio.com \
--cc=linux-crypto@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).