From: "Thorsten.Bschorr" <thorsten@bschorr.de>
To: linux-kernel@vger.kernel.org
Cc: Evgeniy Polyakov <zbr@ioremap.net>, David Fries <David@Fries.net>
Subject: [PATCH] Avoid null-pointer access in w1/slaves/w1_therm
Date: Fri, 27 Feb 2015 09:43:14 +0100 [thread overview]
Message-ID: <54F02E22.5050901@bschorr.de> (raw)
In-Reply-To: <CA+1k2cH5Y+RngvEbgE3CW5g+bO3V1ytDJC=u6DLVDZvbEOhu5A@mail.gmail.com>
w1_slave_show unlocks the bus while waiting for the sensor
to convert the temperature. If the sensor gets disconnected
during that time, sl->family_data could get NULL.
Note: the w1_slave pointer inside w1_slave_show is protected by
sysfs-mutex
---
drivers/w1/slaves/w1_therm.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index 1f11a20..3a14cb1 100644
--- a/drivers/w1/slaves/w1_therm.c
+++ b/drivers/w1/slaves/w1_therm.c
@@ -236,6 +236,12 @@ static ssize_t w1_slave_show(struct device *device,
i = mutex_lock_interruptible(&dev->bus_mutex);
if (i != 0)
return i;
+
+ /* Ensure that device is still there -
+ * it could have gone while we unlocked the bus.
+ * Note: sl is still protected by sysfs-mutex */
+ if(!sl->family_data)
+ return -ENODEV;
} else if (!w1_strong_pullup) {
sleep_rem = msleep_interruptible(tm);
if (sleep_rem != 0) {
--
1.8.4.5
---
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next prev parent reply other threads:[~2015-02-27 8:43 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CA+1k2cH5Y+RngvEbgE3CW5g+bO3V1ytDJC=u6DLVDZvbEOhu5A@mail.gmail.com>
[not found] ` <CA+1k2cF1frcEUu-L_cSJxTp=GKExn6Vt2rdCeY=zrhM62FUggw@mail.gmail.com>
[not found] ` <CA+1k2cEwtY+U7TS3rpmMp5nEBokO8vwhcOiD0ExVQnuoB=XVLQ@mail.gmail.com>
2015-02-23 17:09 ` Fwd: w1/slaves/w1_therm: null-ptr access of sl->family_data Thorsten Bschorr
2015-02-24 1:37 ` David Fries
2015-02-25 9:28 ` Thorsten Bschorr
2015-02-27 8:43 ` Thorsten.Bschorr [this message]
2015-02-28 20:17 ` [PATCH] Avoid null-pointer access in w1/slaves/w1_therm David Fries
[not found] ` <369891425174502@web4m.yandex.ru>
2015-03-01 2:17 ` David Fries
2015-03-01 13:04 ` Thorsten Bschorr
2015-03-02 0:17 ` David Fries
2015-03-04 15:36 ` Евгений Поляков
2015-03-08 21:14 ` David Fries
2015-03-09 22:47 ` Thorsten Bschorr
2015-03-09 23:09 ` David Fries
2015-03-10 0:05 ` Thorsten Bschorr
2015-03-10 0:34 ` Thorsten Bschorr
2015-03-12 0:44 ` David Fries
2015-03-10 13:52 ` Evgeniy Polyakov
2015-03-12 0:54 ` David Fries
2015-03-14 20:55 ` Evgeniy Polyakov
2015-03-18 4:20 ` David Fries
2015-03-18 15:18 ` Evgeniy Polyakov
2015-03-19 0:09 ` David Fries
[not found] ` <CADq11+-tZmQEVUL=sHC64i4auC_5i=+y2yBcMTaJMdD5Z0dE6w@mail.gmail.com>
2015-04-16 3:51 ` David Fries
2015-04-16 11:57 ` Evgeniy Polyakov
[not found] ` <CA+1k2cFw+2NTOtbSaJ1S=kBAn2Mj62DTeZo68V9t1Wk-7m7GyA@mail.gmail.com>
2015-04-17 12:55 ` Evgeniy Polyakov
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