<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/linux, branch v6.1.76</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>serial: core: fix kernel-doc for uart_port_unlock_irqrestore()</title>
<updated>2024-02-01T00:17:12+00:00</updated>
<author>
<name>Randy Dunlap</name>
<email>rdunlap@infradead.org</email>
</author>
<published>2023-09-27T04:41:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e90c7d26cab159b80b63ff520c54e0f4de02e1d6'/>
<id>e90c7d26cab159b80b63ff520c54e0f4de02e1d6</id>
<content type='text'>
commit 29bff582b74ed0bdb7e6986482ad9e6799ea4d2f upstream.

Fix the function name to avoid a kernel-doc warning:

include/linux/serial_core.h:666: warning: expecting prototype for uart_port_lock_irqrestore(). Prototype was for uart_port_unlock_irqrestore() instead

Fixes: b0af4bcb4946 ("serial: core: Provide port lock wrappers")
Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: John Ogness &lt;john.ogness@linutronix.de&gt;
Cc: linux-serial@vger.kernel.org
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Jiri Slaby &lt;jirislaby@kernel.org&gt;
Reviewed-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://lore.kernel.org/r/20230927044128.4748-1-rdunlap@infradead.org
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 29bff582b74ed0bdb7e6986482ad9e6799ea4d2f upstream.

Fix the function name to avoid a kernel-doc warning:

include/linux/serial_core.h:666: warning: expecting prototype for uart_port_lock_irqrestore(). Prototype was for uart_port_unlock_irqrestore() instead

Fixes: b0af4bcb4946 ("serial: core: Provide port lock wrappers")
Signed-off-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: John Ogness &lt;john.ogness@linutronix.de&gt;
Cc: linux-serial@vger.kernel.org
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Jiri Slaby &lt;jirislaby@kernel.org&gt;
Reviewed-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://lore.kernel.org/r/20230927044128.4748-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/entry/ia32: Ensure s32 is sign extended to s64</title>
<updated>2024-02-01T00:17:12+00:00</updated>
<author>
<name>Richard Palethorpe</name>
<email>rpalethorpe@suse.com</email>
</author>
<published>2024-01-10T13:01:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c02d3872c8dd53c2760520992b6ce527081553c4'/>
<id>c02d3872c8dd53c2760520992b6ce527081553c4</id>
<content type='text'>
commit 56062d60f117dccfb5281869e0ab61e090baf864 upstream.

Presently ia32 registers stored in ptregs are unconditionally cast to
unsigned int by the ia32 stub. They are then cast to long when passed to
__se_sys*, but will not be sign extended.

This takes the sign of the syscall argument into account in the ia32
stub. It still casts to unsigned int to avoid implementation specific
behavior. However then casts to int or unsigned int as necessary. So that
the following cast to long sign extends the value.

This fixes the io_pgetevents02 LTP test when compiled with -m32. Presently
the systemcall io_pgetevents_time64() unexpectedly accepts -1 for the
maximum number of events.

It doesn't appear other systemcalls with signed arguments are effected
because they all have compat variants defined and wired up.

Fixes: ebeb8c82ffaf ("syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION and x32")
Suggested-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Richard Palethorpe &lt;rpalethorpe@suse.com&gt;
Signed-off-by: Nikolay Borisov &lt;nik.borisov@suse.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240110130122.3836513-1-nik.borisov@suse.com
Link: https://lore.kernel.org/ltp/20210921130127.24131-1-rpalethorpe@suse.com/
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 56062d60f117dccfb5281869e0ab61e090baf864 upstream.

Presently ia32 registers stored in ptregs are unconditionally cast to
unsigned int by the ia32 stub. They are then cast to long when passed to
__se_sys*, but will not be sign extended.

This takes the sign of the syscall argument into account in the ia32
stub. It still casts to unsigned int to avoid implementation specific
behavior. However then casts to int or unsigned int as necessary. So that
the following cast to long sign extends the value.

This fixes the io_pgetevents02 LTP test when compiled with -m32. Presently
the systemcall io_pgetevents_time64() unexpectedly accepts -1 for the
maximum number of events.

It doesn't appear other systemcalls with signed arguments are effected
because they all have compat variants defined and wired up.

Fixes: ebeb8c82ffaf ("syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION and x32")
Suggested-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Richard Palethorpe &lt;rpalethorpe@suse.com&gt;
Signed-off-by: Nikolay Borisov &lt;nik.borisov@suse.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240110130122.3836513-1-nik.borisov@suse.com
Link: https://lore.kernel.org/ltp/20210921130127.24131-1-rpalethorpe@suse.com/
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>serial: core: Provide port lock wrappers</title>
<updated>2024-02-01T00:17:10+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2023-09-14T18:37:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4fd9a021214208f9667ca9ed461713ea2e2e04f1'/>
<id>4fd9a021214208f9667ca9ed461713ea2e2e04f1</id>
<content type='text'>
[ Upstream commit b0af4bcb49464c221ad5f95d40f2b1b252ceedcc ]

When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.

So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.

All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.

Provide wrapper functions for spin_[un]lock*(port-&gt;lock) invocations so
that the console mechanics can be applied later on at a single place and
does not require to copy the same logic all over the drivers.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
Signed-off-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://lore.kernel.org/r/20230914183831.587273-2-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Stable-dep-of: 9915753037eb ("serial: sc16is7xx: fix unconditional activation of THRI interrupt")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit b0af4bcb49464c221ad5f95d40f2b1b252ceedcc ]

When a serial port is used for kernel console output, then all
modifications to the UART registers which are done from other contexts,
e.g. getty, termios, are interference points for the kernel console.

So far this has been ignored and the printk output is based on the
principle of hope. The rework of the console infrastructure which aims to
support threaded and atomic consoles, requires to mark sections which
modify the UART registers as unsafe. This allows the atomic write function
to make informed decisions and eventually to restore operational state. It
also allows to prevent the regular UART code from modifying UART registers
while printk output is in progress.

All modifications of UART registers are guarded by the UART port lock,
which provides an obvious synchronization point with the console
infrastructure.

Provide wrapper functions for spin_[un]lock*(port-&gt;lock) invocations so
that the console mechanics can be applied later on at a single place and
does not require to copy the same logic all over the drivers.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
Signed-off-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Link: https://lore.kernel.org/r/20230914183831.587273-2-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Stable-dep-of: 9915753037eb ("serial: sc16is7xx: fix unconditional activation of THRI interrupt")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fs/pipe: move check to pipe_has_watch_queue()</title>
<updated>2024-02-01T00:17:09+00:00</updated>
<author>
<name>Max Kellermann</name>
<email>max.kellermann@ionos.com</email>
</author>
<published>2023-09-21T07:57:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6f5c4aaddd637d3e19a222312ba170ab851437dd'/>
<id>6f5c4aaddd637d3e19a222312ba170ab851437dd</id>
<content type='text'>
[ Upstream commit b4bd6b4bac8edd61eb8f7b836969d12c0c6af165 ]

This declutters the code by reducing the number of #ifdefs and makes
the watch_queue checks simpler.  This has no runtime effect; the
machine code is identical.

Signed-off-by: Max Kellermann &lt;max.kellermann@ionos.com&gt;
Message-Id: &lt;20230921075755.1378787-2-max.kellermann@ionos.com&gt;
Reviewed-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Stable-dep-of: e95aada4cb93 ("pipe: wakeup wr_wait after setting max_usage")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit b4bd6b4bac8edd61eb8f7b836969d12c0c6af165 ]

This declutters the code by reducing the number of #ifdefs and makes
the watch_queue checks simpler.  This has no runtime effect; the
machine code is identical.

Signed-off-by: Max Kellermann &lt;max.kellermann@ionos.com&gt;
Message-Id: &lt;20230921075755.1378787-2-max.kellermann@ionos.com&gt;
Reviewed-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Stable-dep-of: e95aada4cb93 ("pipe: wakeup wr_wait after setting max_usage")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>udp: fix busy polling</title>
<updated>2024-02-01T00:17:04+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2024-01-18T20:17:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6646145be9085fc85310323d41196fa7fad0b189'/>
<id>6646145be9085fc85310323d41196fa7fad0b189</id>
<content type='text'>
[ Upstream commit a54d51fb2dfb846aedf3751af501e9688db447f5 ]

Generic sk_busy_loop_end() only looks at sk-&gt;sk_receive_queue
for presence of packets.

Problem is that for UDP sockets after blamed commit, some packets
could be present in another queue: udp_sk(sk)-&gt;reader_queue

In some cases, a busy poller could spin until timeout expiration,
even if some packets are available in udp_sk(sk)-&gt;reader_queue.

v3: - make sk_busy_loop_end() nicer (Willem)

v2: - add a READ_ONCE(sk-&gt;sk_family) in sk_is_inet() to avoid KCSAN splats.
    - add a sk_is_inet() check in sk_is_udp() (Willem feedback)
    - add a sk_is_inet() check in sk_is_tcp().

Fixes: 2276f58ac589 ("udp: use a separate rx queue for packet reception")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Reviewed-by: Willem de Bruijn &lt;willemb@google.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit a54d51fb2dfb846aedf3751af501e9688db447f5 ]

Generic sk_busy_loop_end() only looks at sk-&gt;sk_receive_queue
for presence of packets.

Problem is that for UDP sockets after blamed commit, some packets
could be present in another queue: udp_sk(sk)-&gt;reader_queue

In some cases, a busy poller could spin until timeout expiration,
even if some packets are available in udp_sk(sk)-&gt;reader_queue.

v3: - make sk_busy_loop_end() nicer (Willem)

v2: - add a READ_ONCE(sk-&gt;sk_family) in sk_is_inet() to avoid KCSAN splats.
    - add a sk_is_inet() check in sk_is_udp() (Willem feedback)
    - add a sk_is_inet() check in sk_is_tcp().

Fixes: 2276f58ac589 ("udp: use a separate rx queue for packet reception")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Reviewed-by: Willem de Bruijn &lt;willemb@google.com&gt;
Reviewed-by: Kuniyuki Iwashima &lt;kuniyu@amazon.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm/sparsemem: fix race in accessing memory_section-&gt;usage</title>
<updated>2024-02-01T00:17:02+00:00</updated>
<author>
<name>Charan Teja Kalla</name>
<email>quic_charante@quicinc.com</email>
</author>
<published>2023-10-13T13:04:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=68ed9e33324021e9d6b798e9db00ca3093d2012a'/>
<id>68ed9e33324021e9d6b798e9db00ca3093d2012a</id>
<content type='text'>
commit 5ec8e8ea8b7783fab150cf86404fc38cb4db8800 upstream.

The below race is observed on a PFN which falls into the device memory
region with the system memory configuration where PFN's are such that
[ZONE_NORMAL ZONE_DEVICE ZONE_NORMAL].  Since normal zone start and end
pfn contains the device memory PFN's as well, the compaction triggered
will try on the device memory PFN's too though they end up in NOP(because
pfn_to_online_page() returns NULL for ZONE_DEVICE memory sections).  When
from other core, the section mappings are being removed for the
ZONE_DEVICE region, that the PFN in question belongs to, on which
compaction is currently being operated is resulting into the kernel crash
with CONFIG_SPASEMEM_VMEMAP enabled.  The crash logs can be seen at [1].

compact_zone()			memunmap_pages
-------------			---------------
__pageblock_pfn_to_page
   ......
 (a)pfn_valid():
     valid_section()//return true
			      (b)__remove_pages()-&gt;
				  sparse_remove_section()-&gt;
				    section_deactivate():
				    [Free the array ms-&gt;usage and set
				     ms-&gt;usage = NULL]
     pfn_section_valid()
     [Access ms-&gt;usage which
     is NULL]

NOTE: From the above it can be said that the race is reduced to between
the pfn_valid()/pfn_section_valid() and the section deactivate with
SPASEMEM_VMEMAP enabled.

The commit b943f045a9af("mm/sparse: fix kernel crash with
pfn_section_valid check") tried to address the same problem by clearing
the SECTION_HAS_MEM_MAP with the expectation of valid_section() returns
false thus ms-&gt;usage is not accessed.

Fix this issue by the below steps:

a) Clear SECTION_HAS_MEM_MAP before freeing the -&gt;usage.

b) RCU protected read side critical section will either return NULL
   when SECTION_HAS_MEM_MAP is cleared or can successfully access -&gt;usage.

c) Free the -&gt;usage with kfree_rcu() and set ms-&gt;usage = NULL.  No
   attempt will be made to access -&gt;usage after this as the
   SECTION_HAS_MEM_MAP is cleared thus valid_section() return false.

Thanks to David/Pavan for their inputs on this patch.

[1] https://lore.kernel.org/linux-mm/994410bb-89aa-d987-1f50-f514903c55aa@quicinc.com/

On Snapdragon SoC, with the mentioned memory configuration of PFN's as
[ZONE_NORMAL ZONE_DEVICE ZONE_NORMAL], we are able to see bunch of
issues daily while testing on a device farm.

For this particular issue below is the log.  Though the below log is
not directly pointing to the pfn_section_valid(){ ms-&gt;usage;}, when we
loaded this dump on T32 lauterbach tool, it is pointing.

[  540.578056] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000000
[  540.578068] Mem abort info:
[  540.578070]   ESR = 0x0000000096000005
[  540.578073]   EC = 0x25: DABT (current EL), IL = 32 bits
[  540.578077]   SET = 0, FnV = 0
[  540.578080]   EA = 0, S1PTW = 0
[  540.578082]   FSC = 0x05: level 1 translation fault
[  540.578085] Data abort info:
[  540.578086]   ISV = 0, ISS = 0x00000005
[  540.578088]   CM = 0, WnR = 0
[  540.579431] pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBSBTYPE=--)
[  540.579436] pc : __pageblock_pfn_to_page+0x6c/0x14c
[  540.579454] lr : compact_zone+0x994/0x1058
[  540.579460] sp : ffffffc03579b510
[  540.579463] x29: ffffffc03579b510 x28: 0000000000235800 x27:000000000000000c
[  540.579470] x26: 0000000000235c00 x25: 0000000000000068 x24:ffffffc03579b640
[  540.579477] x23: 0000000000000001 x22: ffffffc03579b660 x21:0000000000000000
[  540.579483] x20: 0000000000235bff x19: ffffffdebf7e3940 x18:ffffffdebf66d140
[  540.579489] x17: 00000000739ba063 x16: 00000000739ba063 x15:00000000009f4bff
[  540.579495] x14: 0000008000000000 x13: 0000000000000000 x12:0000000000000001
[  540.579501] x11: 0000000000000000 x10: 0000000000000000 x9 :ffffff897d2cd440
[  540.579507] x8 : 0000000000000000 x7 : 0000000000000000 x6 :ffffffc03579b5b4
[  540.579512] x5 : 0000000000027f25 x4 : ffffffc03579b5b8 x3 :0000000000000001
[  540.579518] x2 : ffffffdebf7e3940 x1 : 0000000000235c00 x0 :0000000000235800
[  540.579524] Call trace:
[  540.579527]  __pageblock_pfn_to_page+0x6c/0x14c
[  540.579533]  compact_zone+0x994/0x1058
[  540.579536]  try_to_compact_pages+0x128/0x378
[  540.579540]  __alloc_pages_direct_compact+0x80/0x2b0
[  540.579544]  __alloc_pages_slowpath+0x5c0/0xe10
[  540.579547]  __alloc_pages+0x250/0x2d0
[  540.579550]  __iommu_dma_alloc_noncontiguous+0x13c/0x3fc
[  540.579561]  iommu_dma_alloc+0xa0/0x320
[  540.579565]  dma_alloc_attrs+0xd4/0x108

[quic_charante@quicinc.com: use kfree_rcu() in place of synchronize_rcu(), per David]
  Link: https://lkml.kernel.org/r/1698403778-20938-1-git-send-email-quic_charante@quicinc.com
Link: https://lkml.kernel.org/r/1697202267-23600-1-git-send-email-quic_charante@quicinc.com
Fixes: f46edbd1b151 ("mm/sparsemem: add helpers track active portions of a section at boot")
Signed-off-by: Charan Teja Kalla &lt;quic_charante@quicinc.com&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Cc: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&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 5ec8e8ea8b7783fab150cf86404fc38cb4db8800 upstream.

The below race is observed on a PFN which falls into the device memory
region with the system memory configuration where PFN's are such that
[ZONE_NORMAL ZONE_DEVICE ZONE_NORMAL].  Since normal zone start and end
pfn contains the device memory PFN's as well, the compaction triggered
will try on the device memory PFN's too though they end up in NOP(because
pfn_to_online_page() returns NULL for ZONE_DEVICE memory sections).  When
from other core, the section mappings are being removed for the
ZONE_DEVICE region, that the PFN in question belongs to, on which
compaction is currently being operated is resulting into the kernel crash
with CONFIG_SPASEMEM_VMEMAP enabled.  The crash logs can be seen at [1].

compact_zone()			memunmap_pages
-------------			---------------
__pageblock_pfn_to_page
   ......
 (a)pfn_valid():
     valid_section()//return true
			      (b)__remove_pages()-&gt;
				  sparse_remove_section()-&gt;
				    section_deactivate():
				    [Free the array ms-&gt;usage and set
				     ms-&gt;usage = NULL]
     pfn_section_valid()
     [Access ms-&gt;usage which
     is NULL]

NOTE: From the above it can be said that the race is reduced to between
the pfn_valid()/pfn_section_valid() and the section deactivate with
SPASEMEM_VMEMAP enabled.

The commit b943f045a9af("mm/sparse: fix kernel crash with
pfn_section_valid check") tried to address the same problem by clearing
the SECTION_HAS_MEM_MAP with the expectation of valid_section() returns
false thus ms-&gt;usage is not accessed.

Fix this issue by the below steps:

a) Clear SECTION_HAS_MEM_MAP before freeing the -&gt;usage.

b) RCU protected read side critical section will either return NULL
   when SECTION_HAS_MEM_MAP is cleared or can successfully access -&gt;usage.

c) Free the -&gt;usage with kfree_rcu() and set ms-&gt;usage = NULL.  No
   attempt will be made to access -&gt;usage after this as the
   SECTION_HAS_MEM_MAP is cleared thus valid_section() return false.

Thanks to David/Pavan for their inputs on this patch.

[1] https://lore.kernel.org/linux-mm/994410bb-89aa-d987-1f50-f514903c55aa@quicinc.com/

On Snapdragon SoC, with the mentioned memory configuration of PFN's as
[ZONE_NORMAL ZONE_DEVICE ZONE_NORMAL], we are able to see bunch of
issues daily while testing on a device farm.

For this particular issue below is the log.  Though the below log is
not directly pointing to the pfn_section_valid(){ ms-&gt;usage;}, when we
loaded this dump on T32 lauterbach tool, it is pointing.

[  540.578056] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000000
[  540.578068] Mem abort info:
[  540.578070]   ESR = 0x0000000096000005
[  540.578073]   EC = 0x25: DABT (current EL), IL = 32 bits
[  540.578077]   SET = 0, FnV = 0
[  540.578080]   EA = 0, S1PTW = 0
[  540.578082]   FSC = 0x05: level 1 translation fault
[  540.578085] Data abort info:
[  540.578086]   ISV = 0, ISS = 0x00000005
[  540.578088]   CM = 0, WnR = 0
[  540.579431] pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBSBTYPE=--)
[  540.579436] pc : __pageblock_pfn_to_page+0x6c/0x14c
[  540.579454] lr : compact_zone+0x994/0x1058
[  540.579460] sp : ffffffc03579b510
[  540.579463] x29: ffffffc03579b510 x28: 0000000000235800 x27:000000000000000c
[  540.579470] x26: 0000000000235c00 x25: 0000000000000068 x24:ffffffc03579b640
[  540.579477] x23: 0000000000000001 x22: ffffffc03579b660 x21:0000000000000000
[  540.579483] x20: 0000000000235bff x19: ffffffdebf7e3940 x18:ffffffdebf66d140
[  540.579489] x17: 00000000739ba063 x16: 00000000739ba063 x15:00000000009f4bff
[  540.579495] x14: 0000008000000000 x13: 0000000000000000 x12:0000000000000001
[  540.579501] x11: 0000000000000000 x10: 0000000000000000 x9 :ffffff897d2cd440
[  540.579507] x8 : 0000000000000000 x7 : 0000000000000000 x6 :ffffffc03579b5b4
[  540.579512] x5 : 0000000000027f25 x4 : ffffffc03579b5b8 x3 :0000000000000001
[  540.579518] x2 : ffffffdebf7e3940 x1 : 0000000000235c00 x0 :0000000000235800
[  540.579524] Call trace:
[  540.579527]  __pageblock_pfn_to_page+0x6c/0x14c
[  540.579533]  compact_zone+0x994/0x1058
[  540.579536]  try_to_compact_pages+0x128/0x378
[  540.579540]  __alloc_pages_direct_compact+0x80/0x2b0
[  540.579544]  __alloc_pages_slowpath+0x5c0/0xe10
[  540.579547]  __alloc_pages+0x250/0x2d0
[  540.579550]  __iommu_dma_alloc_noncontiguous+0x13c/0x3fc
[  540.579561]  iommu_dma_alloc+0xa0/0x320
[  540.579565]  dma_alloc_attrs+0xd4/0x108

[quic_charante@quicinc.com: use kfree_rcu() in place of synchronize_rcu(), per David]
  Link: https://lkml.kernel.org/r/1698403778-20938-1-git-send-email-quic_charante@quicinc.com
Link: https://lkml.kernel.org/r/1697202267-23600-1-git-send-email-quic_charante@quicinc.com
Fixes: f46edbd1b151 ("mm/sparsemem: add helpers track active portions of a section at boot")
Signed-off-by: Charan Teja Kalla &lt;quic_charante@quicinc.com&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Cc: Oscar Salvador &lt;osalvador@suse.de&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm/rmap: fix misplaced parenthesis of a likely()</title>
<updated>2024-02-01T00:17:02+00:00</updated>
<author>
<name>Steven Rostedt (Google)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2023-12-01T19:59:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=367a47ef4cccbb294b159c53b14a5abbd124b642'/>
<id>367a47ef4cccbb294b159c53b14a5abbd124b642</id>
<content type='text'>
commit f67f8d4a8c1e1ebc85a6cbdb9a7266f14863461c upstream.

Running my yearly branch profiler to see where likely/unlikely annotation
may be added or removed, I discovered this:

correct incorrect  %        Function                  File              Line
 ------- ---------  -        --------                  ----              ----
       0   457918 100 page_try_dup_anon_rmap         rmap.h               264
[..]
  458021        0   0 page_try_dup_anon_rmap         rmap.h               265

I thought it was interesting that line 264 of rmap.h had a 100% incorrect
annotation, but the line directly below it was 100% correct. Looking at the
code:

	if (likely(!is_device_private_page(page) &amp;&amp;
	    unlikely(page_needs_cow_for_dma(vma, page))))

It didn't make sense. The "likely()" was around the entire if statement
(not just the "!is_device_private_page(page)"), which also included the
"unlikely()" portion of that if condition.

If the unlikely portion is unlikely to be true, that would make the entire
if condition unlikely to be true, so it made no sense at all to say the
entire if condition is true.

What is more likely to be likely is just the first part of the if statement
before the &amp;&amp; operation. It's likely to be a misplaced parenthesis. And
after making the if condition broken into a likely() &amp;&amp; unlikely(), both
now appear to be correct!

Link: https://lkml.kernel.org/r/20231201145936.5ddfdb50@gandalf.local.home
Fixes:fb3d824d1a46c ("mm/rmap: split page_dup_rmap() into page_dup_file_rmap() and page_try_dup_anon_rmap()")
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&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 f67f8d4a8c1e1ebc85a6cbdb9a7266f14863461c upstream.

Running my yearly branch profiler to see where likely/unlikely annotation
may be added or removed, I discovered this:

correct incorrect  %        Function                  File              Line
 ------- ---------  -        --------                  ----              ----
       0   457918 100 page_try_dup_anon_rmap         rmap.h               264
[..]
  458021        0   0 page_try_dup_anon_rmap         rmap.h               265

I thought it was interesting that line 264 of rmap.h had a 100% incorrect
annotation, but the line directly below it was 100% correct. Looking at the
code:

	if (likely(!is_device_private_page(page) &amp;&amp;
	    unlikely(page_needs_cow_for_dma(vma, page))))

It didn't make sense. The "likely()" was around the entire if statement
(not just the "!is_device_private_page(page)"), which also included the
"unlikely()" portion of that if condition.

If the unlikely portion is unlikely to be true, that would make the entire
if condition unlikely to be true, so it made no sense at all to say the
entire if condition is true.

What is more likely to be likely is just the first part of the if statement
before the &amp;&amp; operation. It's likely to be a misplaced parenthesis. And
after making the if condition broken into a likely() &amp;&amp; unlikely(), both
now appear to be correct!

Link: https://lkml.kernel.org/r/20231201145936.5ddfdb50@gandalf.local.home
Fixes:fb3d824d1a46c ("mm/rmap: split page_dup_rmap() into page_dup_file_rmap() and page_try_dup_anon_rmap()")
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtc: Add support for configuring the UIP timeout for RTC reads</title>
<updated>2024-02-01T00:17:01+00:00</updated>
<author>
<name>Mario Limonciello</name>
<email>mario.limonciello@amd.com</email>
</author>
<published>2023-11-28T05:36:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7971389316e5af7702bbbd25789e642f5b276695'/>
<id>7971389316e5af7702bbbd25789e642f5b276695</id>
<content type='text'>
commit 120931db07b49252aba2073096b595482d71857c upstream.

The UIP timeout is hardcoded to 10ms for all RTC reads, but in some
contexts this might not be enough time. Add a timeout parameter to
mc146818_get_time() and mc146818_get_time_callback().

If UIP timeout is configured by caller to be &gt;=100 ms and a call
takes this long, log a warning.

Make all callers use 10ms to ensure no functional changes.

Cc:  &lt;stable@vger.kernel.org&gt; # 6.1.y
Fixes: ec5895c0f2d8 ("rtc: mc146818-lib: extract mc146818_avoid_UIP")
Signed-off-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Tested-by: Mateusz Jończyk &lt;mat.jonczyk@o2.pl&gt;
Reviewed-by: Mateusz Jończyk &lt;mat.jonczyk@o2.pl&gt;
Acked-by: Mateusz Jończyk &lt;mat.jonczyk@o2.pl&gt;
Link: https://lore.kernel.org/r/20231128053653.101798-4-mario.limonciello@amd.com
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 120931db07b49252aba2073096b595482d71857c upstream.

The UIP timeout is hardcoded to 10ms for all RTC reads, but in some
contexts this might not be enough time. Add a timeout parameter to
mc146818_get_time() and mc146818_get_time_callback().

If UIP timeout is configured by caller to be &gt;=100 ms and a call
takes this long, log a warning.

Make all callers use 10ms to ensure no functional changes.

Cc:  &lt;stable@vger.kernel.org&gt; # 6.1.y
Fixes: ec5895c0f2d8 ("rtc: mc146818-lib: extract mc146818_avoid_UIP")
Signed-off-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Tested-by: Mateusz Jończyk &lt;mat.jonczyk@o2.pl&gt;
Reviewed-by: Mateusz Jończyk &lt;mat.jonczyk@o2.pl&gt;
Acked-by: Mateusz Jończyk &lt;mat.jonczyk@o2.pl&gt;
Link: https://lore.kernel.org/r/20231128053653.101798-4-mario.limonciello@amd.com
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>lsm: new security_file_ioctl_compat() hook</title>
<updated>2024-02-01T00:17:00+00:00</updated>
<author>
<name>Alfred Piccioni</name>
<email>alpic@google.com</email>
</author>
<published>2023-12-19T09:09:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c014490c0b22371349a7c4aa00a107c2d23268fc'/>
<id>c014490c0b22371349a7c4aa00a107c2d23268fc</id>
<content type='text'>
commit f1bb47a31dff6d4b34fb14e99850860ee74bb003 upstream.

Some ioctl commands do not require ioctl permission, but are routed to
other permissions such as FILE_GETATTR or FILE_SETATTR. This routing is
done by comparing the ioctl cmd to a set of 64-bit flags (FS_IOC_*).

However, if a 32-bit process is running on a 64-bit kernel, it emits
32-bit flags (FS_IOC32_*) for certain ioctl operations. These flags are
being checked erroneously, which leads to these ioctl operations being
routed to the ioctl permission, rather than the correct file
permissions.

This was also noted in a RED-PEN finding from a while back -
"/* RED-PEN how should LSM module know it's handling 32bit? */".

This patch introduces a new hook, security_file_ioctl_compat(), that is
called from the compat ioctl syscall. All current LSMs have been changed
to support this hook.

Reviewing the three places where we are currently using
security_file_ioctl(), it appears that only SELinux needs a dedicated
compat change; TOMOYO and SMACK appear to be functional without any
change.

Cc: stable@vger.kernel.org
Fixes: 0b24dcb7f2f7 ("Revert "selinux: simplify ioctl checking"")
Signed-off-by: Alfred Piccioni &lt;alpic@google.com&gt;
Reviewed-by: Stephen Smalley &lt;stephen.smalley.work@gmail.com&gt;
[PM: subject tweak, line length fixes, and alignment corrections]
Signed-off-by: Paul Moore &lt;paul@paul-moore.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 f1bb47a31dff6d4b34fb14e99850860ee74bb003 upstream.

Some ioctl commands do not require ioctl permission, but are routed to
other permissions such as FILE_GETATTR or FILE_SETATTR. This routing is
done by comparing the ioctl cmd to a set of 64-bit flags (FS_IOC_*).

However, if a 32-bit process is running on a 64-bit kernel, it emits
32-bit flags (FS_IOC32_*) for certain ioctl operations. These flags are
being checked erroneously, which leads to these ioctl operations being
routed to the ioctl permission, rather than the correct file
permissions.

This was also noted in a RED-PEN finding from a while back -
"/* RED-PEN how should LSM module know it's handling 32bit? */".

This patch introduces a new hook, security_file_ioctl_compat(), that is
called from the compat ioctl syscall. All current LSMs have been changed
to support this hook.

Reviewing the three places where we are currently using
security_file_ioctl(), it appears that only SELinux needs a dedicated
compat change; TOMOYO and SMACK appear to be functional without any
change.

Cc: stable@vger.kernel.org
Fixes: 0b24dcb7f2f7 ("Revert "selinux: simplify ioctl checking"")
Signed-off-by: Alfred Piccioni &lt;alpic@google.com&gt;
Reviewed-by: Stephen Smalley &lt;stephen.smalley.work@gmail.com&gt;
[PM: subject tweak, line length fixes, and alignment corrections]
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>async: Introduce async_schedule_dev_nocall()</title>
<updated>2024-02-01T00:17:00+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2023-12-27T20:38:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fcf8e37152505e158d77da3f578b01d958a06468'/>
<id>fcf8e37152505e158d77da3f578b01d958a06468</id>
<content type='text'>
commit 7d4b5d7a37bdd63a5a3371b988744b060d5bb86f upstream.

In preparation for subsequent changes, introduce a specialized variant
of async_schedule_dev() that will not invoke the argument function
synchronously when it cannot be scheduled for asynchronous execution.

The new function, async_schedule_dev_nocall(), will be used for fixing
possible deadlocks in the system-wide power management core code.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Stanislaw Gruszka &lt;stanislaw.gruszka@linux.intel.com&gt; for the series.
Tested-by: Youngmin Nam &lt;youngmin.nam@samsung.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&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 7d4b5d7a37bdd63a5a3371b988744b060d5bb86f upstream.

In preparation for subsequent changes, introduce a specialized variant
of async_schedule_dev() that will not invoke the argument function
synchronously when it cannot be scheduled for asynchronous execution.

The new function, async_schedule_dev_nocall(), will be used for fixing
possible deadlocks in the system-wide power management core code.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Stanislaw Gruszka &lt;stanislaw.gruszka@linux.intel.com&gt; for the series.
Tested-by: Youngmin Nam &lt;youngmin.nam@samsung.com&gt;
Reviewed-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
