From patchwork Tue Feb 19 18:49:14 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [51/81] isdn/gigaset: fix zero size border case in debug dump From: Herton Ronaldo Krzesinski X-Patchwork-Id: 221820 Message-Id: <1361299784-8830-52-git-send-email-herton.krzesinski@canonical.com> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Tilman Schmidt , "David S. Miller" Date: Tue, 19 Feb 2013 15:49:14 -0300 3.5.7.6 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Tilman Schmidt commit d721a1752ba544df8d7d36959038b26bc92bdf80 upstream. If subtracting 12 from l leaves zero we'd do a zero size allocation, leading to an oops later when we try to set the NUL terminator. Reported-by: Dan Carpenter Signed-off-by: Tilman Schmidt Signed-off-by: David S. Miller Signed-off-by: Herton Ronaldo Krzesinski --- drivers/isdn/gigaset/capi.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/isdn/gigaset/capi.c b/drivers/isdn/gigaset/capi.c index 27e4a3e..f45b5b0 100644 --- a/drivers/isdn/gigaset/capi.c +++ b/drivers/isdn/gigaset/capi.c @@ -248,6 +248,8 @@ static inline void dump_rawmsg(enum debuglevel level, const char *tag, CAPIMSG_APPID(data), CAPIMSG_MSGID(data), l, CAPIMSG_CONTROL(data)); l -= 12; + if (l <= 0) + return; dbgline = kmalloc(3 * l, GFP_ATOMIC); if (!dbgline) return;