mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Nicolai Stange <nicstange@gmail.com>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David Howells <dhowells@redhat.com>,
	Tadeusz Struk <tadeusz.struk@intel.com>,
	Michal Marek <mmarek@suse.com>,
	linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
	Nicolai Stange <nicstange@gmail.com>
Subject: [PATCH 4/5] lib/mpi: mpi_read_from_buffer(): sanitize short buffer printk
Date: Thu, 26 May 2016 23:19:54 +0200	[thread overview]
Message-ID: <1464297595-24032-5-git-send-email-nicstange@gmail.com> (raw)
In-Reply-To: <1464297595-24032-1-git-send-email-nicstange@gmail.com>

The first two bytes of the input buffer encode its expected length and
mpi_read_from_buffer() prints a console message if the given buffer is too
short.

However, there are some oddities with how this message is printed:
- It is printed at the default loglevel. This is different from the
  one used in the case that the first two bytes' value is unsupportedly
  large, i.e. KERN_INFO.
- The format specifier '%d' is used for unsigned ints.
- It prints the values of nread and *ret_nread. This is redundant since
  the former is always the latter + 1.

Clean this up as follows:
- Use pr_info() rather than printk() with no loglevel.
- Use the format specifiers '%u' in place if '%d'.
- Do not print the redundant 'nread' but the more helpful 'nbytes' value.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
---
 lib/mpi/mpicoder.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
index 869c66c..2f4d039 100644
--- a/lib/mpi/mpicoder.c
+++ b/lib/mpi/mpicoder.c
@@ -99,8 +99,8 @@ MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread)
 
 	nbytes = DIV_ROUND_UP(nbits, 8);
 	if (nbytes + 2 > *ret_nread) {
-		printk("MPI: mpi larger than buffer nread=%d ret_nread=%d\n",
-				*ret_nread + 1, *ret_nread);
+		pr_info("MPI: mpi larger than buffer nbytes=%u ret_nread=%u\n",
+				nbytes, *ret_nread);
 		return ERR_PTR(-EINVAL);
 	}
 
-- 
2.8.2

  parent reply	other threads:[~2016-05-26 21:20 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-26 21:19 [PATCH 0/5] refactor mpi_read_from_buffer() Nicolai Stange
2016-05-26 21:19 ` [PATCH 1/5] lib/mpi: mpi_read_from_buffer(): return error code Nicolai Stange
2016-05-26 21:19 ` [PATCH 2/5] lib/digsig: digsig_verify_rsa(): return -EINVAL if modulo length is zero Nicolai Stange
2016-05-26 21:19 ` [PATCH 3/5] lib/mpi: mpi_read_from_buffer(): return -EINVAL upon too short buffer Nicolai Stange
2016-05-26 21:19 ` Nicolai Stange [this message]
2016-05-26 21:19 ` [PATCH 5/5] lib/mpi: refactor mpi_read_from_buffer() in terms of mpi_read_raw_data() Nicolai Stange
2016-05-31 10:19 ` [PATCH 0/5] refactor mpi_read_from_buffer() Herbert Xu
2016-05-31 19:07   ` Nicolai Stange

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=1464297595-24032-5-git-send-email-nicstange@gmail.com \
    --to=nicstange@gmail.com \
    --cc=dhowells@redhat.com \
    --cc=herbert@gondor.apana.org.au \
    --cc=linux-crypto@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mmarek@suse.com \
    --cc=tadeusz.struk@intel.com \
    /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

Powered by JetHome