<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/nfc/pn533, branch v6.6</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>nfc: Switch i2c drivers back to use .probe()</title>
<updated>2023-05-22T10:41:57+00:00</updated>
<author>
<name>Uwe Kleine-König</name>
<email>u.kleine-koenig@pengutronix.de</email>
</author>
<published>2023-05-20T17:21:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=efc3001f8b44bf5da0f178bd726a73c73f370707'/>
<id>efc3001f8b44bf5da0f178bd726a73c73f370707</id>
<content type='text'>
After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498b5 ("i2c: Switch .probe() to not take an id parameter")
convert back to (the new) .probe() to be able to eventually drop
.probe_new() from struct i2c_driver.

Signed-off-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Reviewed-by: Luca Ceresoli &lt;luca.ceresoli@bootlin.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498b5 ("i2c: Switch .probe() to not take an id parameter")
convert back to (the new) .probe() to be able to eventually drop
.probe_new() from struct i2c_driver.

Signed-off-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Reviewed-by: Luca Ceresoli &lt;luca.ceresoli@bootlin.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nfc: pn533: initialize struct pn533_out_arg properly</title>
<updated>2023-03-10T23:52:25+00:00</updated>
<author>
<name>Fedor Pchelkin</name>
<email>pchelkin@ispras.ru</email>
</author>
<published>2023-03-09T16:50:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=484b7059796e3bc1cb527caa61dfc60da649b4f6'/>
<id>484b7059796e3bc1cb527caa61dfc60da649b4f6</id>
<content type='text'>
struct pn533_out_arg used as a temporary context for out_urb is not
initialized properly. Its uninitialized 'phy' field can be dereferenced in
error cases inside pn533_out_complete() callback function. It causes the
following failure:

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.2.0-rc3-next-20230110-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:pn533_out_complete.cold+0x15/0x44 drivers/nfc/pn533/usb.c:441
Call Trace:
 &lt;IRQ&gt;
 __usb_hcd_giveback_urb+0x2b6/0x5c0 drivers/usb/core/hcd.c:1671
 usb_hcd_giveback_urb+0x384/0x430 drivers/usb/core/hcd.c:1754
 dummy_timer+0x1203/0x32d0 drivers/usb/gadget/udc/dummy_hcd.c:1988
 call_timer_fn+0x1da/0x800 kernel/time/timer.c:1700
 expire_timers+0x234/0x330 kernel/time/timer.c:1751
 __run_timers kernel/time/timer.c:2022 [inline]
 __run_timers kernel/time/timer.c:1995 [inline]
 run_timer_softirq+0x326/0x910 kernel/time/timer.c:2035
 __do_softirq+0x1fb/0xaf6 kernel/softirq.c:571
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:662
 sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1107

Initialize the field with the pn533_usb_phy currently used.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 9dab880d675b ("nfc: pn533: Wait for out_urb's completion in pn533_usb_send_frame()")
Reported-by: syzbot+1e608ba4217c96d1952f@syzkaller.appspotmail.com
Signed-off-by: Fedor Pchelkin &lt;pchelkin@ispras.ru&gt;
Reviewed-by: Simon Horman &lt;simon.horman@corigine.com&gt;
Link: https://lore.kernel.org/r/20230309165050.207390-1-pchelkin@ispras.ru
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
struct pn533_out_arg used as a temporary context for out_urb is not
initialized properly. Its uninitialized 'phy' field can be dereferenced in
error cases inside pn533_out_complete() callback function. It causes the
following failure:

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.2.0-rc3-next-20230110-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:pn533_out_complete.cold+0x15/0x44 drivers/nfc/pn533/usb.c:441
Call Trace:
 &lt;IRQ&gt;
 __usb_hcd_giveback_urb+0x2b6/0x5c0 drivers/usb/core/hcd.c:1671
 usb_hcd_giveback_urb+0x384/0x430 drivers/usb/core/hcd.c:1754
 dummy_timer+0x1203/0x32d0 drivers/usb/gadget/udc/dummy_hcd.c:1988
 call_timer_fn+0x1da/0x800 kernel/time/timer.c:1700
 expire_timers+0x234/0x330 kernel/time/timer.c:1751
 __run_timers kernel/time/timer.c:2022 [inline]
 __run_timers kernel/time/timer.c:1995 [inline]
 run_timer_softirq+0x326/0x910 kernel/time/timer.c:2035
 __do_softirq+0x1fb/0xaf6 kernel/softirq.c:571
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:662
 sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1107

Initialize the field with the pn533_usb_phy currently used.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 9dab880d675b ("nfc: pn533: Wait for out_urb's completion in pn533_usb_send_frame()")
Reported-by: syzbot+1e608ba4217c96d1952f@syzkaller.appspotmail.com
Signed-off-by: Fedor Pchelkin &lt;pchelkin@ispras.ru&gt;
Reviewed-by: Simon Horman &lt;simon.horman@corigine.com&gt;
Link: https://lore.kernel.org/r/20230309165050.207390-1-pchelkin@ispras.ru
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nfc: pn533: Wait for out_urb's completion in pn533_usb_send_frame()</title>
<updated>2023-01-09T07:34:13+00:00</updated>
<author>
<name>Minsuk Kang</name>
<email>linuxlovemin@yonsei.ac.kr</email>
</author>
<published>2023-01-06T08:23:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9dab880d675b9d0dd56c6428e4e8352a3339371d'/>
<id>9dab880d675b9d0dd56c6428e4e8352a3339371d</id>
<content type='text'>
Fix a use-after-free that occurs in hcd when in_urb sent from
pn533_usb_send_frame() is completed earlier than out_urb. Its callback
frees the skb data in pn533_send_async_complete() that is used as a
transfer buffer of out_urb. Wait before sending in_urb until the
callback of out_urb is called. To modify the callback of out_urb alone,
separate the complete function of out_urb and ack_urb.

Found by a modified version of syzkaller.

BUG: KASAN: use-after-free in dummy_timer
Call Trace:
 memcpy (mm/kasan/shadow.c:65)
 dummy_perform_transfer (drivers/usb/gadget/udc/dummy_hcd.c:1352)
 transfer (drivers/usb/gadget/udc/dummy_hcd.c:1453)
 dummy_timer (drivers/usb/gadget/udc/dummy_hcd.c:1972)
 arch_static_branch (arch/x86/include/asm/jump_label.h:27)
 static_key_false (include/linux/jump_label.h:207)
 timer_expire_exit (include/trace/events/timer.h:127)
 call_timer_fn (kernel/time/timer.c:1475)
 expire_timers (kernel/time/timer.c:1519)
 __run_timers (kernel/time/timer.c:1790)
 run_timer_softirq (kernel/time/timer.c:1803)

Fixes: c46ee38620a2 ("NFC: pn533: add NXP pn533 nfc device driver")
Signed-off-by: Minsuk Kang &lt;linuxlovemin@yonsei.ac.kr&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fix a use-after-free that occurs in hcd when in_urb sent from
pn533_usb_send_frame() is completed earlier than out_urb. Its callback
frees the skb data in pn533_send_async_complete() that is used as a
transfer buffer of out_urb. Wait before sending in_urb until the
callback of out_urb is called. To modify the callback of out_urb alone,
separate the complete function of out_urb and ack_urb.

Found by a modified version of syzkaller.

BUG: KASAN: use-after-free in dummy_timer
Call Trace:
 memcpy (mm/kasan/shadow.c:65)
 dummy_perform_transfer (drivers/usb/gadget/udc/dummy_hcd.c:1352)
 transfer (drivers/usb/gadget/udc/dummy_hcd.c:1453)
 dummy_timer (drivers/usb/gadget/udc/dummy_hcd.c:1972)
 arch_static_branch (arch/x86/include/asm/jump_label.h:27)
 static_key_false (include/linux/jump_label.h:207)
 timer_expire_exit (include/trace/events/timer.h:127)
 call_timer_fn (kernel/time/timer.c:1475)
 expire_timers (kernel/time/timer.c:1519)
 __run_timers (kernel/time/timer.c:1790)
 run_timer_softirq (kernel/time/timer.c:1803)

Fixes: c46ee38620a2 ("NFC: pn533: add NXP pn533 nfc device driver")
Signed-off-by: Minsuk Kang &lt;linuxlovemin@yonsei.ac.kr&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: Convert del_timer*() to timer_shutdown*()</title>
<updated>2022-12-25T21:38:09+00:00</updated>
<author>
<name>Steven Rostedt (Google)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2022-12-20T18:45:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=292a089d78d3e2f7944e60bb897c977785a321e3'/>
<id>292a089d78d3e2f7944e60bb897c977785a321e3</id>
<content type='text'>
Due to several bugs caused by timers being re-armed after they are
shutdown and just before they are freed, a new state of timers was added
called "shutdown".  After a timer is set to this state, then it can no
longer be re-armed.

The following script was run to find all the trivial locations where
del_timer() or del_timer_sync() is called in the same function that the
object holding the timer is freed.  It also ignores any locations where
the timer-&gt;function is modified between the del_timer*() and the free(),
as that is not considered a "trivial" case.

This was created by using a coccinelle script and the following
commands:

    $ cat timer.cocci
    @@
    expression ptr, slab;
    identifier timer, rfield;
    @@
    (
    -       del_timer(&amp;ptr-&gt;timer);
    +       timer_shutdown(&amp;ptr-&gt;timer);
    |
    -       del_timer_sync(&amp;ptr-&gt;timer);
    +       timer_shutdown_sync(&amp;ptr-&gt;timer);
    )
      ... when strict
          when != ptr-&gt;timer
    (
            kfree_rcu(ptr, rfield);
    |
            kmem_cache_free(slab, ptr);
    |
            kfree(ptr);
    )

    $ spatch timer.cocci . &gt; /tmp/t.patch
    $ patch -p1 &lt; /tmp/t.patch

Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Acked-by: Pavel Machek &lt;pavel@ucw.cz&gt; [ LED ]
Acked-by: Kalle Valo &lt;kvalo@kernel.org&gt; [ wireless ]
Acked-by: Paolo Abeni &lt;pabeni@redhat.com&gt; [ networking ]
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Due to several bugs caused by timers being re-armed after they are
shutdown and just before they are freed, a new state of timers was added
called "shutdown".  After a timer is set to this state, then it can no
longer be re-armed.

The following script was run to find all the trivial locations where
del_timer() or del_timer_sync() is called in the same function that the
object holding the timer is freed.  It also ignores any locations where
the timer-&gt;function is modified between the del_timer*() and the free(),
as that is not considered a "trivial" case.

This was created by using a coccinelle script and the following
commands:

    $ cat timer.cocci
    @@
    expression ptr, slab;
    identifier timer, rfield;
    @@
    (
    -       del_timer(&amp;ptr-&gt;timer);
    +       timer_shutdown(&amp;ptr-&gt;timer);
    |
    -       del_timer_sync(&amp;ptr-&gt;timer);
    +       timer_shutdown_sync(&amp;ptr-&gt;timer);
    )
      ... when strict
          when != ptr-&gt;timer
    (
            kfree_rcu(ptr, rfield);
    |
            kmem_cache_free(slab, ptr);
    |
            kfree(ptr);
    )

    $ spatch timer.cocci . &gt; /tmp/t.patch
    $ patch -p1 &lt; /tmp/t.patch

Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Acked-by: Pavel Machek &lt;pavel@ucw.cz&gt; [ LED ]
Acked-by: Kalle Valo &lt;kvalo@kernel.org&gt; [ wireless ]
Acked-by: Paolo Abeni &lt;pabeni@redhat.com&gt; [ networking ]
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nfc: pn533: Clear nfc_target before being used</title>
<updated>2022-12-15T04:51:29+00:00</updated>
<author>
<name>Minsuk Kang</name>
<email>linuxlovemin@yonsei.ac.kr</email>
</author>
<published>2022-12-14T01:51:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9f28157778ede0d4f183f7ab3b46995bb400abbe'/>
<id>9f28157778ede0d4f183f7ab3b46995bb400abbe</id>
<content type='text'>
Fix a slab-out-of-bounds read that occurs in nla_put() called from
nfc_genl_send_target() when target-&gt;sensb_res_len, which is duplicated
from an nfc_target in pn533, is too large as the nfc_target is not
properly initialized and retains garbage values. Clear nfc_targets with
memset() before they are used.

Found by a modified version of syzkaller.

BUG: KASAN: slab-out-of-bounds in nla_put
Call Trace:
 memcpy
 nla_put
 nfc_genl_dump_targets
 genl_lock_dumpit
 netlink_dump
 __netlink_dump_start
 genl_family_rcv_msg_dumpit
 genl_rcv_msg
 netlink_rcv_skb
 genl_rcv
 netlink_unicast
 netlink_sendmsg
 sock_sendmsg
 ____sys_sendmsg
 ___sys_sendmsg
 __sys_sendmsg
 do_syscall_64

Fixes: 673088fb42d0 ("NFC: pn533: Send ATR_REQ directly for active device detection")
Fixes: 361f3cb7f9cf ("NFC: DEP link hook implementation for pn533")
Signed-off-by: Minsuk Kang &lt;linuxlovemin@yonsei.ac.kr&gt;
Reviewed-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Link: https://lore.kernel.org/r/20221214015139.119673-1-linuxlovemin@yonsei.ac.kr
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fix a slab-out-of-bounds read that occurs in nla_put() called from
nfc_genl_send_target() when target-&gt;sensb_res_len, which is duplicated
from an nfc_target in pn533, is too large as the nfc_target is not
properly initialized and retains garbage values. Clear nfc_targets with
memset() before they are used.

Found by a modified version of syzkaller.

BUG: KASAN: slab-out-of-bounds in nla_put
Call Trace:
 memcpy
 nla_put
 nfc_genl_dump_targets
 genl_lock_dumpit
 netlink_dump
 __netlink_dump_start
 genl_family_rcv_msg_dumpit
 genl_rcv_msg
 netlink_rcv_skb
 genl_rcv
 netlink_unicast
 netlink_sendmsg
 sock_sendmsg
 ____sys_sendmsg
 ___sys_sendmsg
 __sys_sendmsg
 do_syscall_64

Fixes: 673088fb42d0 ("NFC: pn533: Send ATR_REQ directly for active device detection")
Fixes: 361f3cb7f9cf ("NFC: DEP link hook implementation for pn533")
Signed-off-by: Minsuk Kang &lt;linuxlovemin@yonsei.ac.kr&gt;
Reviewed-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Link: https://lore.kernel.org/r/20221214015139.119673-1-linuxlovemin@yonsei.ac.kr
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nfc: pn533: Convert to i2c's .probe_new()</title>
<updated>2022-11-23T20:50:07+00:00</updated>
<author>
<name>Uwe Kleine-König</name>
<email>u.kleine-koenig@pengutronix.de</email>
</author>
<published>2022-11-23T04:55:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d72c9828a3cbf3110b0c5ce26a81fabc68312254'/>
<id>d72c9828a3cbf3110b0c5ce26a81fabc68312254</id>
<content type='text'>
The probe function doesn't make use of the i2c_device_id * parameter so it
can be trivially converted.

Signed-off-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The probe function doesn't make use of the i2c_device_id * parameter so it
can be trivially converted.

Signed-off-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'v6.0-rc5' into i2c/for-mergewindow</title>
<updated>2022-09-16T19:42:18+00:00</updated>
<author>
<name>Wolfram Sang</name>
<email>wsa@kernel.org</email>
</author>
<published>2022-09-16T19:42:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d819524d3144f4703f45f473fdc85ad7579ae94c'/>
<id>d819524d3144f4703f45f473fdc85ad7579ae94c</id>
<content type='text'>
Linux 6.0-rc5
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Linux 6.0-rc5
</pre>
</div>
</content>
</entry>
<entry>
<title>nfc: pn533: Fix use-after-free bugs caused by pn532_cmd_timeout</title>
<updated>2022-08-22T13:51:30+00:00</updated>
<author>
<name>Duoming Zhou</name>
<email>duoming@zju.edu.cn</email>
</author>
<published>2022-08-18T09:06:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f1e941dbf80a9b8bab0bffbc4cbe41cc7f4c6fb6'/>
<id>f1e941dbf80a9b8bab0bffbc4cbe41cc7f4c6fb6</id>
<content type='text'>
When the pn532 uart device is detaching, the pn532_uart_remove()
is called. But there are no functions in pn532_uart_remove() that
could delete the cmd_timeout timer, which will cause use-after-free
bugs. The process is shown below:

    (thread 1)                  |        (thread 2)
                                |  pn532_uart_send_frame
pn532_uart_remove               |    mod_timer(&amp;pn532-&gt;cmd_timeout,...)
  ...                           |    (wait a time)
  kfree(pn532) //FREE           |    pn532_cmd_timeout
                                |      pn532_uart_send_frame
                                |        pn532-&gt;... //USE

This patch adds del_timer_sync() in pn532_uart_remove() in order to
prevent the use-after-free bugs. What's more, the pn53x_unregister_nfc()
is well synchronized, it sets nfc_dev-&gt;shutting_down to true and there
are no syscalls could restart the cmd_timeout timer.

Fixes: c656aa4c27b1 ("nfc: pn533: add UART phy driver")
Signed-off-by: Duoming Zhou &lt;duoming@zju.edu.cn&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When the pn532 uart device is detaching, the pn532_uart_remove()
is called. But there are no functions in pn532_uart_remove() that
could delete the cmd_timeout timer, which will cause use-after-free
bugs. The process is shown below:

    (thread 1)                  |        (thread 2)
                                |  pn532_uart_send_frame
pn532_uart_remove               |    mod_timer(&amp;pn532-&gt;cmd_timeout,...)
  ...                           |    (wait a time)
  kfree(pn532) //FREE           |    pn532_cmd_timeout
                                |      pn532_uart_send_frame
                                |        pn532-&gt;... //USE

This patch adds del_timer_sync() in pn532_uart_remove() in order to
prevent the use-after-free bugs. What's more, the pn53x_unregister_nfc()
is well synchronized, it sets nfc_dev-&gt;shutting_down to true and there
are no syscalls could restart the cmd_timeout timer.

Fixes: c656aa4c27b1 ("nfc: pn533: add UART phy driver")
Signed-off-by: Duoming Zhou &lt;duoming@zju.edu.cn&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>i2c: Make remove callback return void</title>
<updated>2022-08-16T10:46:26+00:00</updated>
<author>
<name>Uwe Kleine-König</name>
<email>u.kleine-koenig@pengutronix.de</email>
</author>
<published>2022-08-15T08:02:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ed5c2f5fd10dda07263f79f338a512c0f49f76f5'/>
<id>ed5c2f5fd10dda07263f79f338a512c0f49f76f5</id>
<content type='text'>
The value returned by an i2c driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Reviewed-by: Peter Senna Tschudin &lt;peter.senna@gmail.com&gt;
Reviewed-by: Jeremy Kerr &lt;jk@codeconstruct.com.au&gt;
Reviewed-by: Benjamin Mugnier &lt;benjamin.mugnier@foss.st.com&gt;
Reviewed-by: Javier Martinez Canillas &lt;javierm@redhat.com&gt;
Reviewed-by: Crt Mori &lt;cmo@melexis.com&gt;
Reviewed-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: Marek Behún &lt;kabel@kernel.org&gt; # for leds-turris-omnia
Acked-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Reviewed-by: Petr Machata &lt;petrm@nvidia.com&gt; # for mlxsw
Reviewed-by: Maximilian Luz &lt;luzmaximilian@gmail.com&gt; # for surface3_power
Acked-by: Srinivas Pandruvada &lt;srinivas.pandruvada@linux.intel.com&gt; # for bmc150-accel-i2c + kxcjk-1013
Reviewed-by: Hans Verkuil &lt;hverkuil-cisco@xs4all.nl&gt; # for media/* + staging/media/*
Acked-by: Miguel Ojeda &lt;ojeda@kernel.org&gt; # for auxdisplay/ht16k33 + auxdisplay/lcd2s
Reviewed-by: Luca Ceresoli &lt;luca.ceresoli@bootlin.com&gt; # for versaclock5
Reviewed-by: Ajay Gupta &lt;ajayg@nvidia.com&gt; # for ucsi_ccg
Acked-by: Jonathan Cameron &lt;Jonathan.Cameron@huawei.com&gt; # for iio
Acked-by: Peter Rosin &lt;peda@axentia.se&gt; # for i2c-mux-*, max9860
Acked-by: Adrien Grassein &lt;adrien.grassein@gmail.com&gt; # for lontium-lt8912b
Reviewed-by: Jean Delvare &lt;jdelvare@suse.de&gt; # for hwmon, i2c-core and i2c/muxes
Acked-by: Corey Minyard &lt;cminyard@mvista.com&gt; # for IPMI
Reviewed-by: Vladimir Oltean &lt;olteanv@gmail.com&gt;
Acked-by: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;
Acked-by: Sebastian Reichel &lt;sebastian.reichel@collabora.com&gt; # for drivers/power
Acked-by: Krzysztof Hałasa &lt;khalasa@piap.pl&gt;
Signed-off-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Signed-off-by: Wolfram Sang &lt;wsa@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The value returned by an i2c driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Reviewed-by: Peter Senna Tschudin &lt;peter.senna@gmail.com&gt;
Reviewed-by: Jeremy Kerr &lt;jk@codeconstruct.com.au&gt;
Reviewed-by: Benjamin Mugnier &lt;benjamin.mugnier@foss.st.com&gt;
Reviewed-by: Javier Martinez Canillas &lt;javierm@redhat.com&gt;
Reviewed-by: Crt Mori &lt;cmo@melexis.com&gt;
Reviewed-by: Heikki Krogerus &lt;heikki.krogerus@linux.intel.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: Marek Behún &lt;kabel@kernel.org&gt; # for leds-turris-omnia
Acked-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Reviewed-by: Petr Machata &lt;petrm@nvidia.com&gt; # for mlxsw
Reviewed-by: Maximilian Luz &lt;luzmaximilian@gmail.com&gt; # for surface3_power
Acked-by: Srinivas Pandruvada &lt;srinivas.pandruvada@linux.intel.com&gt; # for bmc150-accel-i2c + kxcjk-1013
Reviewed-by: Hans Verkuil &lt;hverkuil-cisco@xs4all.nl&gt; # for media/* + staging/media/*
Acked-by: Miguel Ojeda &lt;ojeda@kernel.org&gt; # for auxdisplay/ht16k33 + auxdisplay/lcd2s
Reviewed-by: Luca Ceresoli &lt;luca.ceresoli@bootlin.com&gt; # for versaclock5
Reviewed-by: Ajay Gupta &lt;ajayg@nvidia.com&gt; # for ucsi_ccg
Acked-by: Jonathan Cameron &lt;Jonathan.Cameron@huawei.com&gt; # for iio
Acked-by: Peter Rosin &lt;peda@axentia.se&gt; # for i2c-mux-*, max9860
Acked-by: Adrien Grassein &lt;adrien.grassein@gmail.com&gt; # for lontium-lt8912b
Reviewed-by: Jean Delvare &lt;jdelvare@suse.de&gt; # for hwmon, i2c-core and i2c/muxes
Acked-by: Corey Minyard &lt;cminyard@mvista.com&gt; # for IPMI
Reviewed-by: Vladimir Oltean &lt;olteanv@gmail.com&gt;
Acked-by: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;
Acked-by: Sebastian Reichel &lt;sebastian.reichel@collabora.com&gt; # for drivers/power
Acked-by: Krzysztof Hałasa &lt;khalasa@piap.pl&gt;
Signed-off-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Signed-off-by: Wolfram Sang &lt;wsa@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>nfc: pn533: Fix buggy cleanup order</title>
<updated>2022-05-18T12:58:13+00:00</updated>
<author>
<name>Lin Ma</name>
<email>linma@zju.edu.cn</email>
</author>
<published>2022-05-18T10:53:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b8cedb7093b2d1394cae9b86494cba4b62d3a30a'/>
<id>b8cedb7093b2d1394cae9b86494cba4b62d3a30a</id>
<content type='text'>
When removing the pn533 device (i2c or USB), there is a logic error. The
original code first cancels the worker (flush_delayed_work) and then
destroys the workqueue (destroy_workqueue), leaving the timer the last
one to be deleted (del_timer). This result in a possible race condition
in a multi-core preempt-able kernel. That is, if the cleanup
(pn53x_common_clean) is concurrently run with the timer handler
(pn533_listen_mode_timer), the timer can queue the poll_work to the
already destroyed workqueue, causing use-after-free.

This patch reorder the cleanup: it uses the del_timer_sync to make sure
the handler is finished before the routine will destroy the workqueue.
Note that the timer cannot be activated by the worker again.

static void pn533_wq_poll(struct work_struct *work)
...
 rc = pn533_send_poll_frame(dev);
 if (rc)
   return;

 if (cur_mod-&gt;len == 0 &amp;&amp; dev-&gt;poll_mod_count &gt; 1)
   mod_timer(&amp;dev-&gt;listen_timer, ...);

That is, the mod_timer can be called only when pn533_send_poll_frame()
returns no error, which is impossible because the device is detaching
and the lower driver should return ENODEV code.

Signed-off-by: Lin Ma &lt;linma@zju.edu.cn&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When removing the pn533 device (i2c or USB), there is a logic error. The
original code first cancels the worker (flush_delayed_work) and then
destroys the workqueue (destroy_workqueue), leaving the timer the last
one to be deleted (del_timer). This result in a possible race condition
in a multi-core preempt-able kernel. That is, if the cleanup
(pn53x_common_clean) is concurrently run with the timer handler
(pn533_listen_mode_timer), the timer can queue the poll_work to the
already destroyed workqueue, causing use-after-free.

This patch reorder the cleanup: it uses the del_timer_sync to make sure
the handler is finished before the routine will destroy the workqueue.
Note that the timer cannot be activated by the worker again.

static void pn533_wq_poll(struct work_struct *work)
...
 rc = pn533_send_poll_frame(dev);
 if (rc)
   return;

 if (cur_mod-&gt;len == 0 &amp;&amp; dev-&gt;poll_mod_count &gt; 1)
   mod_timer(&amp;dev-&gt;listen_timer, ...);

That is, the mod_timer can be called only when pn533_send_poll_frame()
returns no error, which is impossible because the device is detaching
and the lower driver should return ENODEV code.

Signed-off-by: Lin Ma &lt;linma@zju.edu.cn&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
</feed>
