Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1658008

[PATCH 4.4 29/53] HID: wacom: Have wacom_tpc_irq guard against possible NULL dereference

From Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newsgroups linux.kernel
Subject [PATCH 4.4 29/53] HID: wacom: Have wacom_tpc_irq guard against possible NULL dereference
Date 2017-06-05 19:30 +0200
Message-ID <tP3Zh-5PM-33@gated-at.bofh.it> (permalink)
References <tP33b-5dS-15@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jason Gerecke <killertofu@gmail.com>

commit 2ac97f0f6654da14312d125005c77a6010e0ea38 upstream.

The following Smatch complaint was generated in response to commit
2a6cdbd ("HID: wacom: Introduce new 'touch_input' device"):

    drivers/hid/wacom_wac.c:1586 wacom_tpc_irq()
             error: we previously assumed 'wacom->touch_input' could be null (see line 1577)

The 'touch_input' and 'pen_input' variables point to the 'struct input_dev'
used for relaying touch and pen events to userspace, respectively. If a
device does not have a touch interface or pen interface, the associated
input variable is NULL. The 'wacom_tpc_irq()' function is responsible for
forwarding input reports to a more-specific IRQ handler function. An
unknown report could theoretically be mistaken as e.g. a touch report
on a device which does not have a touch interface. This can be prevented
by only calling the pen/touch functions are called when the pen/touch
pointers are valid.

Fixes: 2a6cdbd ("HID: wacom: Introduce new 'touch_input' device")
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: Ping Cheng <ping.cheng@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/hid/wacom_wac.c |   47 ++++++++++++++++++++++++-----------------------
 1 file changed, 24 insertions(+), 23 deletions(-)

--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -1440,37 +1440,38 @@ static int wacom_tpc_irq(struct wacom_wa
 {
 	unsigned char *data = wacom->data;
 
-	if (wacom->pen_input)
+	if (wacom->pen_input) {
 		dev_dbg(wacom->pen_input->dev.parent,
 			"%s: received report #%d\n", __func__, data[0]);
-	else if (wacom->touch_input)
+
+		if (len == WACOM_PKGLEN_PENABLED ||
+		    data[0] == WACOM_REPORT_PENABLED)
+			return wacom_tpc_pen(wacom);
+	}
+	else if (wacom->touch_input) {
 		dev_dbg(wacom->touch_input->dev.parent,
 			"%s: received report #%d\n", __func__, data[0]);
 
-	switch (len) {
-	case WACOM_PKGLEN_TPC1FG:
-		return wacom_tpc_single_touch(wacom, len);
-
-	case WACOM_PKGLEN_TPC2FG:
-		return wacom_tpc_mt_touch(wacom);
-
-	case WACOM_PKGLEN_PENABLED:
-		return wacom_tpc_pen(wacom);
-
-	default:
-		switch (data[0]) {
-		case WACOM_REPORT_TPC1FG:
-		case WACOM_REPORT_TPCHID:
-		case WACOM_REPORT_TPCST:
-		case WACOM_REPORT_TPC1FGE:
+		switch (len) {
+		case WACOM_PKGLEN_TPC1FG:
 			return wacom_tpc_single_touch(wacom, len);
 
-		case WACOM_REPORT_TPCMT:
-		case WACOM_REPORT_TPCMT2:
-			return wacom_mt_touch(wacom);
+		case WACOM_PKGLEN_TPC2FG:
+			return wacom_tpc_mt_touch(wacom);
 
-		case WACOM_REPORT_PENABLED:
-			return wacom_tpc_pen(wacom);
+		default:
+			switch (data[0]) {
+			case WACOM_REPORT_TPC1FG:
+			case WACOM_REPORT_TPCHID:
+			case WACOM_REPORT_TPCST:
+			case WACOM_REPORT_TPC1FGE:
+				return wacom_tpc_single_touch(wacom, len);
+
+			case WACOM_REPORT_TPCMT:
+			case WACOM_REPORT_TPCMT2:
+				return wacom_mt_touch(wacom);
+
+			}
 		}
 	}

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 4.4 00/53] 4.4.71-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 18:30 +0200
  [PATCH 4.4 37/53] mm/migrate: fix refcount handling when !hugepage_migration_supported() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:20 +0200
  [PATCH 4.4 44/53] xfs: prevent multi-fsb dir readahead from reading random blocks Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:20 +0200
  [PATCH 4.4 40/53] xfs: Fix missed holes in SEEK_HOLE implementation Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:20 +0200
  [PATCH 4.4 46/53] xfs: support ability to wait on new inodes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:20 +0200
  [PATCH 4.4 41/53] xfs: fix off-by-one on max nr_pages in xfs_find_get_desired_pgoff() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:20 +0200
  [PATCH 4.4 14/53] ipv6: Check ip6_find_1stfragopt() return value properly. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 51/53] xfs: fix unaligned access in xfs_btree_visit_blocks Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 47/53] xfs: update ag iterator to support wait on new inodes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 28/53] mmc: sdhci-iproc: suppress spurious interrupt with Multiblock read Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 11/53] tcp: eliminate negative reordering in tcp_clean_rtx_queue Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 50/53] xfs: bad assertion for delalloc an extent that start at i_size Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 52/53] xfs: in _attrlist_by_handle, copy the cursor back to userspace Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 34/53] ALSA: hda - apply STAC_9200_DELL_M22 quirk for Dell Latitude D430 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 29/53] HID: wacom: Have wacom_tpc_irq guard against possible NULL dereference Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 12/53] net: Improve handling of failures on link and route dumps Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 27/53] i2c: i2c-tiny-usb: fix buffer not being DMA capable Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 15/53] bridge: netlink: check vlan_default_pvid range Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 05/53] s390/qeth: unbreak OSM and OSN support Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 20/53] virtio-net: enable TSO/checksum offloads for Q-in-Q vlans Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 49/53] xfs: fix indlen accounting error on partial delalloc conversion Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 25/53] net: phy: marvell: Limit errata to 88m1101 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 03/53] ipv6/dccp: do not inherit ipv6_mc_list from parent Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 39/53] PCI/PM: Add needs_resume flag to avoid suspend complete optimization Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
    Re: [PATCH 4.4 39/53] PCI/PM: Add needs_resume flag to avoid  suspend complete optimization Ben Hutchings <ben.hutchings@codethink.co.uk> - 2017-06-06 18:20 +0200
      Re: [PATCH 4.4 39/53] PCI/PM: Add needs_resume flag to avoid suspend  complete optimization Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-07 11:50 +0200
  [PATCH 4.4 07/53] s390/qeth: add missing hash table initializations Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
    Re: [PATCH 4.4 07/53] s390/qeth: add missing hash table  initializations Julian Wiedmann <jwi@linux.vnet.ibm.com> - 2017-06-06 10:20 +0200
      Re: [PATCH 4.4 07/53] s390/qeth: add missing hash table  initializations Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-06 11:00 +0200
  [PATCH 4.4 04/53] s390/qeth: handle sysfs error during initialization Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:30 +0200
  [PATCH 4.4 02/53] dccp/tcp: do not inherit mc_list from parent Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:40 +0200
  [PATCH 4.4 01/53] sparc: Fix -Wstringop-overflow warning Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-05 19:40 +0200
  Re: [PATCH 4.4 00/53] 4.4.71-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2017-06-05 22:40 +0200
  Re: [PATCH 4.4 00/53] 4.4.71-stable review Guenter Roeck <linux@roeck-us.net> - 2017-06-06 00:10 +0200
    Re: [PATCH 4.4 00/53] 4.4.71-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-06 09:30 +0200

csiph-web