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From: Russ Gorby <russ.gorby@intel.com>
To: Greg Kroah-Hartman <gregkh@suse.de>,
	Russ Gorby <russ.gorby@intel.com>,
	linux-kernel@vger.kernel.org
Cc: suhail.ahmed@intel.com, russ.gorby@intel.com
Subject: [PATCHv2 7/7] char: n_gsm: improper skb_pull() use was leaking framed data
Date: Fri,  3 Jun 2011 16:44:02 -0700	[thread overview]
Message-ID: <1307144642-5915-8-git-send-email-russ.gorby@intel.com> (raw)
In-Reply-To: <[PATCHv2 0/5] N_GSM patchset : 06/03/2011: v2>

gsm_dlci_data_output_framed() was doing:
memcpy(dp, skb_pull(dlci->skb, len), len);

The problem is skb_pull() returns the post-increment skb->data ptr
so the first chunk can be leaked.

Signed-off-by: Russ Gorby <russ.gorby@intel.com>
---
 drivers/tty/n_gsm.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 7f95bfd..660c5ca 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -903,7 +903,8 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
 		*dp++ = last << 7 | first << 6 | 1;	/* EA */
 		len--;
 	}
-	memcpy(dp, skb_pull(dlci->skb, len), len);
+	memcpy(dp, dlci->skb->data, len);
+	skb_pull(dlci->skb, len);
 	__gsm_data_queue(dlci, msg);
 	if (last) {
 		kfree_skb(dlci->skb);
-- 
1.7.0.4


      parent reply	other threads:[~2011-06-03 23:44 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <[PATCHv2 0/5] N_GSM patchset : 06/03/2011: v2>
2011-06-03 23:43 ` [PATCHv2 0/5] N_GSM patchset : 06/03/2011: v2 Russ Gorby
2011-06-06 23:35   ` Greg KH
2011-06-03 23:43 ` [PATCHv2 1/7] tty: n_gsm: Add raw-ip support Russ Gorby
2011-06-03 23:43 ` [PATCHv2 2/7] tty: n_gsm: expose gsmtty device nodes at ldisc open time Russ Gorby
2011-06-03 23:43 ` [PATCHv2 3/7] tty: n_gsm: Added refcount usage to gsm_mux and gsm_dlci structs Russ Gorby
2011-06-03 23:43 ` [PATCHv2 4/7] tty: n_gsm: initiate close of all DLCIs during mux shutdown Russ Gorby
2011-06-03 23:44 ` [PATCHv2 5/7] tty: n_gsm: Fixed NULL ptr OOPs in tty_write_room() Russ Gorby
2011-06-03 23:44 ` [PATCHv2 6/7] tty: n_gsm: Fixed logic to decode break signal in modem status Russ Gorby
2011-06-03 23:44 ` Russ Gorby [this message]

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