<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/rtc, branch v4.14.65</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>rtc: tps65910: fix possible race condition</title>
<updated>2018-08-03T05:50:32+00:00</updated>
<author>
<name>Alexandre Belloni</name>
<email>alexandre.belloni@bootlin.com</email>
</author>
<published>2018-05-17T20:26:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9f25b548732cfdcda2b0bd638497934b4a8eaaf6'/>
<id>9f25b548732cfdcda2b0bd638497934b4a8eaaf6</id>
<content type='text'>
[ Upstream commit e6000a438e534ee0afd9e83b67f4e23a26dd1067 ]

The IRQ is requested before the struct rtc is allocated and registered, but
this struct is used in the IRQ handler. This may lead to a NULL pointer
dereference.

Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc
before requesting the IRQ.

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit e6000a438e534ee0afd9e83b67f4e23a26dd1067 ]

The IRQ is requested before the struct rtc is allocated and registered, but
this struct is used in the IRQ handler. This may lead to a NULL pointer
dereference.

Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc
before requesting the IRQ.

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtc: vr41xx: fix possible race condition</title>
<updated>2018-08-03T05:50:32+00:00</updated>
<author>
<name>Alexandre Belloni</name>
<email>alexandre.belloni@bootlin.com</email>
</author>
<published>2018-05-17T20:47:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8f5e7596fe3a41be914056bab79230b2c71d7e63'/>
<id>8f5e7596fe3a41be914056bab79230b2c71d7e63</id>
<content type='text'>
[ Upstream commit 9a99247c9c1d1c95c6e8153d013979aac6111c6e ]

The probe function is not allowed to fail after the RTC is registered
because the following may happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev-&gt;owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod-&gt;module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 9a99247c9c1d1c95c6e8153d013979aac6111c6e ]

The probe function is not allowed to fail after the RTC is registered
because the following may happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev-&gt;owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod-&gt;module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtc: tps6586x: fix possible race condition</title>
<updated>2018-08-03T05:50:32+00:00</updated>
<author>
<name>Alexandre Belloni</name>
<email>alexandre.belloni@bootlin.com</email>
</author>
<published>2018-05-17T20:48:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=aca6728fa1ede62972c266b30e618240ef8e9e6e'/>
<id>aca6728fa1ede62972c266b30e618240ef8e9e6e</id>
<content type='text'>
[ Upstream commit 63d22063073b0ab46d1e06fe633fb5de8f5c58e1 ]

The probe function is not allowed to fail after the RTC is registered
because the following may happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev-&gt;owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod-&gt;module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 63d22063073b0ab46d1e06fe633fb5de8f5c58e1 ]

The probe function is not allowed to fail after the RTC is registered
because the following may happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev-&gt;owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod-&gt;module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtc: ensure rtc_set_alarm fails when alarms are not supported</title>
<updated>2018-08-03T05:50:23+00:00</updated>
<author>
<name>Alexandre Belloni</name>
<email>alexandre.belloni@bootlin.com</email>
</author>
<published>2018-06-05T21:09:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6a929b97b7770573728611551568a4399e3c2da7'/>
<id>6a929b97b7770573728611551568a4399e3c2da7</id>
<content type='text'>
[ Upstream commit abfdff44bc38e9e2ef7929f633fb8462632299d4 ]

When using RTC_ALM_SET or RTC_WKALM_SET with rtc_wkalrm.enabled not set,
rtc_timer_enqueue() is not called and rtc_set_alarm() may succeed but the
subsequent RTC_AIE_ON ioctl will fail. RTC_ALM_READ would also fail in that
case.

Ensure rtc_set_alarm() fails when alarms are not supported to avoid letting
programs think the alarms are working for a particular RTC when they are
not.

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit abfdff44bc38e9e2ef7929f633fb8462632299d4 ]

When using RTC_ALM_SET or RTC_WKALM_SET with rtc_wkalrm.enabled not set,
rtc_timer_enqueue() is not called and rtc_set_alarm() may succeed but the
subsequent RTC_AIE_ON ioctl will fail. RTC_ALM_READ would also fail in that
case.

Ensure rtc_set_alarm() fails when alarms are not supported to avoid letting
programs think the alarms are working for a particular RTC when they are
not.

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtc: sun6i: Fix bit_idx value for clk_register_gate</title>
<updated>2018-07-03T09:24:59+00:00</updated>
<author>
<name>Michael Trimarchi</name>
<email>michael@amarulasolutions.com</email>
</author>
<published>2018-05-30T18:27:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=88896a963b4e80f5d4f6fe508ab7ce399d7bcb4c'/>
<id>88896a963b4e80f5d4f6fe508ab7ce399d7bcb4c</id>
<content type='text'>
commit 09018d4bd7994c2c9f775029bc24589bc85f76fa upstream.

clk-gate core will take bit_idx through clk_register_gate
and then do clk_gate_ops by using BIT(bit_idx), but rtc-sun6i
is passing bit_idx as BIT(bit_idx) it becomes BIT(BIT(bit_idx)
which is wrong and eventually external gate clock is not enabling.

This patch fixed by passing bit index and the original change
introduced from below commit.
"rtc: sun6i: Add support for the external oscillator gate"
(sha1: 	17ecd246414b3a0fe0cb248c86977a8bda465b7b)

Signed-off-by: Michael Trimarchi &lt;michael@amarulasolutions.com&gt;
Fixes: 17ecd246414b ("rtc: sun6i: Add support for the external oscillator gate")
Cc: stable@vger.kernel.org
Signed-off-by: Jagan Teki &lt;jagan@amarulasolutions.com&gt;
Acked-by: Maxime Ripard &lt;maxime.ripard@bootlin.com&gt;
Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 09018d4bd7994c2c9f775029bc24589bc85f76fa upstream.

clk-gate core will take bit_idx through clk_register_gate
and then do clk_gate_ops by using BIT(bit_idx), but rtc-sun6i
is passing bit_idx as BIT(bit_idx) it becomes BIT(BIT(bit_idx)
which is wrong and eventually external gate clock is not enabling.

This patch fixed by passing bit index and the original change
introduced from below commit.
"rtc: sun6i: Add support for the external oscillator gate"
(sha1: 	17ecd246414b3a0fe0cb248c86977a8bda465b7b)

Signed-off-by: Michael Trimarchi &lt;michael@amarulasolutions.com&gt;
Fixes: 17ecd246414b ("rtc: sun6i: Add support for the external oscillator gate")
Cc: stable@vger.kernel.org
Signed-off-by: Jagan Teki &lt;jagan@amarulasolutions.com&gt;
Acked-by: Maxime Ripard &lt;maxime.ripard@bootlin.com&gt;
Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>rtc: goldfish: Add missing MODULE_LICENSE</title>
<updated>2018-05-25T14:18:02+00:00</updated>
<author>
<name>James Hogan</name>
<email>jhogan@kernel.org</email>
</author>
<published>2018-01-16T14:45:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6b73dfbd3cfc9af7cb50fc109585b8735e404201'/>
<id>6b73dfbd3cfc9af7cb50fc109585b8735e404201</id>
<content type='text'>
[ Upstream commit 82d632b85eb89f97051530f556cb49ee1c04bde7 ]

Fix the following warning in MIPS allmodconfig by adding a
MODULE_LICENSE() at the end of rtc-goldfish.c, based on the file header
comment which says GNU General Public License version 2:

WARNING: modpost: missing MODULE_LICENSE() in drivers/rtc/rtc-goldfish.o

Fixes: f22d9cdcb5eb ("rtc: goldfish: Add RTC driver for Android emulator")
Signed-off-by: James Hogan &lt;jhogan@kernel.org&gt;
Cc: Miodrag Dinic &lt;miodrag.dinic@mips.com&gt;
Cc: Alessandro Zummo &lt;a.zummo@towertech.it&gt;
Cc: Alexandre Belloni &lt;alexandre.belloni@free-electrons.com&gt;
Cc: linux-rtc@vger.kernel.org
Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 82d632b85eb89f97051530f556cb49ee1c04bde7 ]

Fix the following warning in MIPS allmodconfig by adding a
MODULE_LICENSE() at the end of rtc-goldfish.c, based on the file header
comment which says GNU General Public License version 2:

WARNING: modpost: missing MODULE_LICENSE() in drivers/rtc/rtc-goldfish.o

Fixes: f22d9cdcb5eb ("rtc: goldfish: Add RTC driver for Android emulator")
Signed-off-by: James Hogan &lt;jhogan@kernel.org&gt;
Cc: Miodrag Dinic &lt;miodrag.dinic@mips.com&gt;
Cc: Alessandro Zummo &lt;a.zummo@towertech.it&gt;
Cc: Alexandre Belloni &lt;alexandre.belloni@free-electrons.com&gt;
Cc: linux-rtc@vger.kernel.org
Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtc: rp5c01: fix possible race condition</title>
<updated>2018-05-25T14:18:01+00:00</updated>
<author>
<name>Alexandre Belloni</name>
<email>alexandre.belloni@bootlin.com</email>
</author>
<published>2018-02-12T22:47:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6f34e436509ec90703365972cf0aef90d41c009f'/>
<id>6f34e436509ec90703365972cf0aef90d41c009f</id>
<content type='text'>
[ Upstream commit bcdd559268039d8340d38fa58668393596e29fdc ]

The probe function is not allowed to fail after registering the RTC because
the following may happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev-&gt;owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod-&gt;module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Switch to devm_rtc_allocate_device/rtc_register_device to register the rtc
as late as possible.

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit bcdd559268039d8340d38fa58668393596e29fdc ]

The probe function is not allowed to fail after registering the RTC because
the following may happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev-&gt;owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod-&gt;module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Switch to devm_rtc_allocate_device/rtc_register_device to register the rtc
as late as possible.

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtc: tx4939: avoid unintended sign extension on a 24 bit shift</title>
<updated>2018-05-25T14:18:01+00:00</updated>
<author>
<name>Colin Ian King</name>
<email>colin.king@canonical.com</email>
</author>
<published>2018-02-15T19:36:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=78227b671e0db669eac33f2302bef45a7d5ea33a'/>
<id>78227b671e0db669eac33f2302bef45a7d5ea33a</id>
<content type='text'>
[ Upstream commit 347876ad47b9923ce26e686173bbf46581802ffa ]

The shifting of buf[5] by 24 bits to the left will be promoted to
a 32 bit signed int and then sign-extended to an unsigned long. If
the top bit of buf[5] is set then all then all the upper bits sec
end up as also being set because of the sign-extension. Fix this by
casting buf[5] to an unsigned long before the shift.

Detected by CoverityScan, CID#1465292 ("Unintended sign extension")

Fixes: 0e1492330cd2 ("rtc: add rtc-tx4939 driver")
Signed-off-by: Colin Ian King &lt;colin.king@canonical.com&gt;
Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 347876ad47b9923ce26e686173bbf46581802ffa ]

The shifting of buf[5] by 24 bits to the left will be promoted to
a 32 bit signed int and then sign-extended to an unsigned long. If
the top bit of buf[5] is set then all then all the upper bits sec
end up as also being set because of the sign-extension. Fix this by
casting buf[5] to an unsigned long before the shift.

Detected by CoverityScan, CID#1465292 ("Unintended sign extension")

Fixes: 0e1492330cd2 ("rtc: add rtc-tx4939 driver")
Signed-off-by: Colin Ian King &lt;colin.king@canonical.com&gt;
Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtc: m41t80: fix race conditions</title>
<updated>2018-05-25T14:18:01+00:00</updated>
<author>
<name>Alexandre Belloni</name>
<email>alexandre.belloni@bootlin.com</email>
</author>
<published>2018-02-25T20:14:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=459aa4904ab20d0544dc3e237d264e7211fc7aa5'/>
<id>459aa4904ab20d0544dc3e237d264e7211fc7aa5</id>
<content type='text'>
[ Upstream commit 10d0c768cc6d581523d673b9d1b54213f8a5eb24 ]

The IRQ is requested before the struct rtc is allocated and registered, but
this struct is used in the IRQ handler, leading to:

Unable to handle kernel NULL pointer dereference at virtual address 0000017c
pgd = a38a2f9b
[0000017c] *pgd=00000000
Internal error: Oops: 5 [#1] ARM
Modules linked in:
CPU: 0 PID: 613 Comm: irq/48-m41t80 Not tainted 4.16.0-rc1+ #42
Hardware name: Atmel SAMA5
PC is at mutex_lock+0x14/0x38
LR is at m41t80_handle_irq+0x1c/0x9c
pc : [&lt;c06e864c&gt;]    lr : [&lt;c04b70f0&gt;]    psr: 20000013
sp : dec73f30  ip : 00000000  fp : dec56d98
r10: df437cf0  r9 : c0a03008  r8 : c0145ffc
r7 : df5c4300  r6 : dec568d0  r5 : df593000  r4 : 0000017c
r3 : df592800  r2 : 60000013  r1 : df593000  r0 : 0000017c
Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 10c53c7d  Table: 20004059  DAC: 00000051
Process irq/48-m41t80 (pid: 613, stack limit = 0xb52d091e)
Stack: (0xdec73f30 to 0xdec74000)
3f20:                                     dec56840 df5c4300 00000001 df5c4300
3f40: c0145ffc c0146018 dec56840 ffffe000 00000001 c0146290 dec567c0 00000000
3f60: c0146084 ed7c9a62 c014615c dec56d80 dec567c0 00000000 dec72000 dec56840
3f80: c014615c c012ffc0 dec72000 dec567c0 c012fe80 00000000 00000000 00000000
3fa0: 00000000 00000000 00000000 c01010e8 00000000 00000000 00000000 00000000
3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3fe0: 00000000 00000000 00000000 00000000 00000013 00000000 29282726 2d2c2b2a
[&lt;c06e864c&gt;] (mutex_lock) from [&lt;c04b70f0&gt;] (m41t80_handle_irq+0x1c/0x9c)
[&lt;c04b70f0&gt;] (m41t80_handle_irq) from [&lt;c0146018&gt;] (irq_thread_fn+0x1c/0x54)
[&lt;c0146018&gt;] (irq_thread_fn) from [&lt;c0146290&gt;] (irq_thread+0x134/0x1c0)
[&lt;c0146290&gt;] (irq_thread) from [&lt;c012ffc0&gt;] (kthread+0x140/0x148)
[&lt;c012ffc0&gt;] (kthread) from [&lt;c01010e8&gt;] (ret_from_fork+0x14/0x2c)
Exception stack(0xdec73fb0 to 0xdec73ff8)
3fa0:                                     00000000 00000000 00000000 00000000
3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3fe0: 00000000 00000000 00000000 00000000 00000013 00000000
Code: e3c33d7f e3c3303f f5d0f000 e593300c (e1901f9f)
---[ end trace 22b027302eb7c604 ]---
genirq: exiting task "irq/48-m41t80" (613) is an active IRQ thread (irq 48)

Also, there is another possible race condition. The probe function is not
allowed to fail after the RTC is registered because the following may
happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev-&gt;owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod-&gt;module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc
before requesting the IRQ and register it as late as possible.

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;

Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 10d0c768cc6d581523d673b9d1b54213f8a5eb24 ]

The IRQ is requested before the struct rtc is allocated and registered, but
this struct is used in the IRQ handler, leading to:

Unable to handle kernel NULL pointer dereference at virtual address 0000017c
pgd = a38a2f9b
[0000017c] *pgd=00000000
Internal error: Oops: 5 [#1] ARM
Modules linked in:
CPU: 0 PID: 613 Comm: irq/48-m41t80 Not tainted 4.16.0-rc1+ #42
Hardware name: Atmel SAMA5
PC is at mutex_lock+0x14/0x38
LR is at m41t80_handle_irq+0x1c/0x9c
pc : [&lt;c06e864c&gt;]    lr : [&lt;c04b70f0&gt;]    psr: 20000013
sp : dec73f30  ip : 00000000  fp : dec56d98
r10: df437cf0  r9 : c0a03008  r8 : c0145ffc
r7 : df5c4300  r6 : dec568d0  r5 : df593000  r4 : 0000017c
r3 : df592800  r2 : 60000013  r1 : df593000  r0 : 0000017c
Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 10c53c7d  Table: 20004059  DAC: 00000051
Process irq/48-m41t80 (pid: 613, stack limit = 0xb52d091e)
Stack: (0xdec73f30 to 0xdec74000)
3f20:                                     dec56840 df5c4300 00000001 df5c4300
3f40: c0145ffc c0146018 dec56840 ffffe000 00000001 c0146290 dec567c0 00000000
3f60: c0146084 ed7c9a62 c014615c dec56d80 dec567c0 00000000 dec72000 dec56840
3f80: c014615c c012ffc0 dec72000 dec567c0 c012fe80 00000000 00000000 00000000
3fa0: 00000000 00000000 00000000 c01010e8 00000000 00000000 00000000 00000000
3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3fe0: 00000000 00000000 00000000 00000000 00000013 00000000 29282726 2d2c2b2a
[&lt;c06e864c&gt;] (mutex_lock) from [&lt;c04b70f0&gt;] (m41t80_handle_irq+0x1c/0x9c)
[&lt;c04b70f0&gt;] (m41t80_handle_irq) from [&lt;c0146018&gt;] (irq_thread_fn+0x1c/0x54)
[&lt;c0146018&gt;] (irq_thread_fn) from [&lt;c0146290&gt;] (irq_thread+0x134/0x1c0)
[&lt;c0146290&gt;] (irq_thread) from [&lt;c012ffc0&gt;] (kthread+0x140/0x148)
[&lt;c012ffc0&gt;] (kthread) from [&lt;c01010e8&gt;] (ret_from_fork+0x14/0x2c)
Exception stack(0xdec73fb0 to 0xdec73ff8)
3fa0:                                     00000000 00000000 00000000 00000000
3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3fe0: 00000000 00000000 00000000 00000000 00000013 00000000
Code: e3c33d7f e3c3303f f5d0f000 e593300c (e1901f9f)
---[ end trace 22b027302eb7c604 ]---
genirq: exiting task "irq/48-m41t80" (613) is an active IRQ thread (irq 48)

Also, there is another possible race condition. The probe function is not
allowed to fail after the RTC is registered because the following may
happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev-&gt;owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod-&gt;module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc
before requesting the IRQ and register it as late as possible.

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;

Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtc: rk808: fix possible race condition</title>
<updated>2018-05-25T14:18:01+00:00</updated>
<author>
<name>Alexandre Belloni</name>
<email>alexandre.belloni@bootlin.com</email>
</author>
<published>2018-02-21T10:57:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6266010c38950eec0dd304d04a79540e6115b71b'/>
<id>6266010c38950eec0dd304d04a79540e6115b71b</id>
<content type='text'>
[ Upstream commit 201fac95e799c3d0304ec724d555e1251b9f6e84 ]

The probe function is not allowed to fail after registering the RTC because
the following may happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev-&gt;owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod-&gt;module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Switch to devm_rtc_allocate_device/rtc_register_device to register the rtc
as late as possible.

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 201fac95e799c3d0304ec724d555e1251b9f6e84 ]

The probe function is not allowed to fail after registering the RTC because
the following may happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev-&gt;owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod-&gt;module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Switch to devm_rtc_allocate_device/rtc_register_device to register the rtc
as late as possible.

Signed-off-by: Alexandre Belloni &lt;alexandre.belloni@bootlin.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
