LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Jesper Juhl <jj@chaosbits.net>
To: linux-kernel@vger.kernel.org
Cc: Chas Williams <chas@cmf.nrl.navy.mil>,
	linux-atm-general@lists.sourceforge.net, netdev@vger.kernel.org,
	Nathan Williams <nathan@traverse.com.au>,
	David Woodhouse <dwmw2@infradead.org>,
	Treker Chen <treker@xrio.com>
Subject: [PATCH] ATM, Solos PCI ADSL2+: Don't deref NULL pointer if net_ratelimit() and alloc_skb() interact badly.
Date: Sun, 13 Feb 2011 21:49:32 +0100 (CET)	[thread overview]
Message-ID: <alpine.LNX.2.00.1102132142460.18930@swampdragon.chaosbits.net> (raw)

If alloc_skb() fails to allocate memory and returns NULL then we want to 
return -ENOMEM from drivers/atm/solos-pci.c::popen() regardless of the 
value of net_ratelimit(). The way the code is today, we may not return if 
net_ratelimit() returns 0, then we'll proceed to pass a NULL pointer to 
skb_put() which will blow up in our face.
This patch ensures that we always return -ENOMEM on alloc_skb() failure 
and only let the dev_warn() be controlled by the value of net_ratelimit().

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
---
 solos-pci.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
index 73fb1c4..25ef1a4 100644
--- a/drivers/atm/solos-pci.c
+++ b/drivers/atm/solos-pci.c
@@ -866,8 +866,9 @@ static int popen(struct atm_vcc *vcc)
 	}
 
 	skb = alloc_skb(sizeof(*header), GFP_ATOMIC);
-	if (!skb && net_ratelimit()) {
-		dev_warn(&card->dev->dev, "Failed to allocate sk_buff in popen()\n");
+	if (!skb) {
+		if (net_ratelimit())
+			dev_warn(&card->dev->dev, "Failed to allocate sk_buff in popen()\n");
 		return -ENOMEM;
 	}
 	header = (void *)skb_put(skb, sizeof(*header));


-- 
Jesper Juhl <jj@chaosbits.net>            http://www.chaosbits.net/
Plain text mails only, please.
Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html


             reply	other threads:[~2011-02-13 20:50 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-13 20:49 Jesper Juhl [this message]
2011-02-14  0:55 ` David Miller

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=alpine.LNX.2.00.1102132142460.18930@swampdragon.chaosbits.net \
    --to=jj@chaosbits.net \
    --cc=chas@cmf.nrl.navy.mil \
    --cc=dwmw2@infradead.org \
    --cc=linux-atm-general@lists.sourceforge.net \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nathan@traverse.com.au \
    --cc=netdev@vger.kernel.org \
    --cc=treker@xrio.com \
    --subject='Re: [PATCH] ATM, Solos PCI ADSL2+: Don'\''t deref NULL pointer if net_ratelimit() and alloc_skb() interact badly.' \
    /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

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).