<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/base, branch v6.15.4</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>software node: Correct a OOB check in software_node_get_reference_args()</title>
<updated>2025-06-27T10:13:27+00:00</updated>
<author>
<name>Zijun Hu</name>
<email>quic_zijuhu@quicinc.com</email>
</author>
<published>2025-04-14T11:36:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7af18e42bdefe1dba5bcb32555a4d524fd504939'/>
<id>7af18e42bdefe1dba5bcb32555a4d524fd504939</id>
<content type='text'>
[ Upstream commit 31e4e12e0e9609850cefd4b2e1adf782f56337d6 ]

software_node_get_reference_args() wants to get @index-th element, so
the property value requires at least '(index + 1) * sizeof(*ref)' bytes
but that can not be guaranteed by current OOB check, and may cause OOB
for malformed property.

Fix by using as OOB check '((index + 1) * sizeof(*ref) &gt; prop-&gt;length)'.

Reviewed-by: Sakari Ailus &lt;sakari.ailus@linux.intel.com&gt;
Signed-off-by: Zijun Hu &lt;quic_zijuhu@quicinc.com&gt;
Link: https://lore.kernel.org/r/20250414-fix_swnode-v2-1-9c9e6ae11eab@quicinc.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&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 31e4e12e0e9609850cefd4b2e1adf782f56337d6 ]

software_node_get_reference_args() wants to get @index-th element, so
the property value requires at least '(index + 1) * sizeof(*ref)' bytes
but that can not be guaranteed by current OOB check, and may cause OOB
for malformed property.

Fix by using as OOB check '((index + 1) * sizeof(*ref) &gt; prop-&gt;length)'.

Reviewed-by: Sakari Ailus &lt;sakari.ailus@linux.intel.com&gt;
Signed-off-by: Zijun Hu &lt;quic_zijuhu@quicinc.com&gt;
Link: https://lore.kernel.org/r/20250414-fix_swnode-v2-1-9c9e6ae11eab@quicinc.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: runtime: fix denying of auto suspend in pm_suspend_timer_fn()</title>
<updated>2025-06-27T10:13:13+00:00</updated>
<author>
<name>Charan Teja Kalla</name>
<email>quic_charante@quicinc.com</email>
</author>
<published>2025-05-15T06:41:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0bd887636e7642664905bae2a7fdd5092e69310e'/>
<id>0bd887636e7642664905bae2a7fdd5092e69310e</id>
<content type='text'>
[ Upstream commit 40d3b40dce375d6f1c1dbf08d79eed3aed6c691d ]

pm_runtime_put_autosuspend() schedules a hrtimer to expire
at "dev-&gt;power.timer_expires". If the hrtimer's callback,
pm_suspend_timer_fn(), observes that the current time equals
"dev-&gt;power.timer_expires", it unexpectedly bails out instead of
proceeding with runtime suspend.

pm_suspend_timer_fn():

 if (expires &gt; 0 &amp;&amp; expires &lt; ktime_get_mono_fast_ns()) {
 	dev-&gt;power.timer_expires = 0;
 	rpm_suspend(..)
 }

Additionally, as -&gt;timer_expires is not cleared, all the future auto
suspend requests will not schedule hrtimer to perform auto suspend.

rpm_suspend():

 if ((rpmflags &amp; RPM_AUTO) &amp;&amp;...) {
 	if (!(dev-&gt;power.timer_expires &amp;&amp; ...) { &lt;-- this will fail.
 		hrtimer_start_range_ns(&amp;dev-&gt;power.suspend_timer,...);
 	}
 }

Fix this by as well checking if current time reaches the set expiration.

Co-developed-by: Patrick Daly &lt;quic_pdaly@quicinc.com&gt;
Signed-off-by: Patrick Daly &lt;quic_pdaly@quicinc.com&gt;
Signed-off-by: Charan Teja Kalla &lt;quic_charante@quicinc.com&gt;
Link: https://patch.msgid.link/20250515064125.1211561-1-quic_charante@quicinc.com
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&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 40d3b40dce375d6f1c1dbf08d79eed3aed6c691d ]

pm_runtime_put_autosuspend() schedules a hrtimer to expire
at "dev-&gt;power.timer_expires". If the hrtimer's callback,
pm_suspend_timer_fn(), observes that the current time equals
"dev-&gt;power.timer_expires", it unexpectedly bails out instead of
proceeding with runtime suspend.

pm_suspend_timer_fn():

 if (expires &gt; 0 &amp;&amp; expires &lt; ktime_get_mono_fast_ns()) {
 	dev-&gt;power.timer_expires = 0;
 	rpm_suspend(..)
 }

Additionally, as -&gt;timer_expires is not cleared, all the future auto
suspend requests will not schedule hrtimer to perform auto suspend.

rpm_suspend():

 if ((rpmflags &amp; RPM_AUTO) &amp;&amp;...) {
 	if (!(dev-&gt;power.timer_expires &amp;&amp; ...) { &lt;-- this will fail.
 		hrtimer_start_range_ns(&amp;dev-&gt;power.suspend_timer,...);
 	}
 }

Fix this by as well checking if current time reaches the set expiration.

Co-developed-by: Patrick Daly &lt;quic_pdaly@quicinc.com&gt;
Signed-off-by: Patrick Daly &lt;quic_pdaly@quicinc.com&gt;
Signed-off-by: Charan Teja Kalla &lt;quic_charante@quicinc.com&gt;
Link: https://patch.msgid.link/20250515064125.1211561-1-quic_charante@quicinc.com
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>platform-msi: Add msi_remove_device_irq_domain() in platform_device_msi_free_irqs_all()</title>
<updated>2025-06-27T10:13:12+00:00</updated>
<author>
<name>Frank Li</name>
<email>Frank.Li@nxp.com</email>
</author>
<published>2025-04-14T18:30:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=288e81a72e157f0a7e31c1f0e47ffd5ce7288f90'/>
<id>288e81a72e157f0a7e31c1f0e47ffd5ce7288f90</id>
<content type='text'>
[ Upstream commit 9a958e1fd40d6fae8c66385687a00ebd9575a7d2 ]

platform_device_msi_init_and_alloc_irqs() performs two tasks: allocating
the MSI domain for a platform device, and allocate a number of MSIs in that
domain.

platform_device_msi_free_irqs_all() only frees the MSIs, and leaves the MSI
domain alive.

Given that platform_device_msi_init_and_alloc_irqs() is the sole tool a
platform device has to allocate platform MSIs, it makes sense for
platform_device_msi_free_irqs_all() to teardown the MSI domain at the same
time as the MSIs.

This avoids warnings and unexpected behaviours when a driver repeatedly
allocates and frees MSIs.

Signed-off-by: Frank Li &lt;Frank.Li@nxp.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Acked-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/all/20250414-ep-msi-v18-1-f69b49917464@nxp.com
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 9a958e1fd40d6fae8c66385687a00ebd9575a7d2 ]

platform_device_msi_init_and_alloc_irqs() performs two tasks: allocating
the MSI domain for a platform device, and allocate a number of MSIs in that
domain.

platform_device_msi_free_irqs_all() only frees the MSIs, and leaves the MSI
domain alive.

Given that platform_device_msi_init_and_alloc_irqs() is the sole tool a
platform device has to allocate platform MSIs, it makes sense for
platform_device_msi_free_irqs_all() to teardown the MSI domain at the same
time as the MSIs.

This avoids warnings and unexpected behaviours when a driver repeatedly
allocates and frees MSIs.

Signed-off-by: Frank Li &lt;Frank.Li@nxp.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Acked-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/all/20250414-ep-msi-v18-1-f69b49917464@nxp.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: sleep: Fix power.is_suspended cleanup for direct-complete devices</title>
<updated>2025-06-19T13:40:41+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2025-06-03T16:19:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c7d216830d49952fc849bd5363ae1b029c3a1e0e'/>
<id>c7d216830d49952fc849bd5363ae1b029c3a1e0e</id>
<content type='text'>
[ Upstream commit d46c4c839c20a599a0eb8d73708ce401f9c7d06d ]

Commit 03f1444016b7 ("PM: sleep: Fix handling devices with direct_complete
set on errors") caused power.is_suspended to be set for devices with
power.direct_complete set, but it forgot to ensure the clearing of that
flag for them in device_resume(), so power.is_suspended is still set for
them during the next system suspend-resume cycle.

If that cycle is aborted in dpm_suspend(), the subsequent invocation of
dpm_resume() will trigger a device_resume() call for every device and
because power.is_suspended is set for the devices in question, they will
not be skipped by device_resume() as expected which causes scary error
messages to be logged (as appropriate).

To address this issue, move the clearing of power.is_suspended in
device_resume() immediately after the power.is_suspended check so it
will be always cleared for all devices processed by that function.

Fixes: 03f1444016b7 ("PM: sleep: Fix handling devices with direct_complete set on errors")
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4280
Reported-and-tested-by: Chris Bainbridge &lt;chris.bainbridge@gmail.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Link: https://patch.msgid.link/4990586.GXAFRqVoOG@rjwysocki.net
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 d46c4c839c20a599a0eb8d73708ce401f9c7d06d ]

Commit 03f1444016b7 ("PM: sleep: Fix handling devices with direct_complete
set on errors") caused power.is_suspended to be set for devices with
power.direct_complete set, but it forgot to ensure the clearing of that
flag for them in device_resume(), so power.is_suspended is still set for
them during the next system suspend-resume cycle.

If that cycle is aborted in dpm_suspend(), the subsequent invocation of
dpm_resume() will trigger a device_resume() call for every device and
because power.is_suspended is set for the devices in question, they will
not be skipped by device_resume() as expected which causes scary error
messages to be logged (as appropriate).

To address this issue, move the clearing of power.is_suspended in
device_resume() immediately after the power.is_suspended check so it
will be always cleared for all devices processed by that function.

Fixes: 03f1444016b7 ("PM: sleep: Fix handling devices with direct_complete set on errors")
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4280
Reported-and-tested-by: Chris Bainbridge &lt;chris.bainbridge@gmail.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Link: https://patch.msgid.link/4990586.GXAFRqVoOG@rjwysocki.net
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: runtime: Add new devm functions</title>
<updated>2025-06-19T13:39:25+00:00</updated>
<author>
<name>Bence Csókás</name>
<email>csokas.bence@prolan.hu</email>
</author>
<published>2025-03-27T19:59:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c3102581a71d74b4740a1c0b4cfc8d7faade93f1'/>
<id>c3102581a71d74b4740a1c0b4cfc8d7faade93f1</id>
<content type='text'>
[ Upstream commit 73db799bf5efc5a04654bb3ff6c9bf63a0dfa473 ]

Add `devm_pm_runtime_set_active_enabled()` and
`devm_pm_runtime_get_noresume()` for simplifying
common cases in drivers.

Signed-off-by: Bence Csókás &lt;csokas.bence@prolan.hu&gt;
Link: https://patch.msgid.link/20250327195928.680771-3-csokas.bence@prolan.hu
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Stable-dep-of: 8856eafcc05e ("spi: atmel-quadspi: Fix unbalanced pm_runtime by using devm_ API")
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 73db799bf5efc5a04654bb3ff6c9bf63a0dfa473 ]

Add `devm_pm_runtime_set_active_enabled()` and
`devm_pm_runtime_get_noresume()` for simplifying
common cases in drivers.

Signed-off-by: Bence Csókás &lt;csokas.bence@prolan.hu&gt;
Link: https://patch.msgid.link/20250327195928.680771-3-csokas.bence@prolan.hu
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Stable-dep-of: 8856eafcc05e ("spi: atmel-quadspi: Fix unbalanced pm_runtime by using devm_ API")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'its-for-linus-20250509' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2025-05-12T00:23:03+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-05-12T00:23:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6f5bf947bab06f37ff931c359fd5770c4d9cbf87'/>
<id>6f5bf947bab06f37ff931c359fd5770c4d9cbf87</id>
<content type='text'>
Pull x86 ITS mitigation from Dave Hansen:
 "Mitigate Indirect Target Selection (ITS) issue.

  I'd describe this one as a good old CPU bug where the behavior is
  _obviously_ wrong, but since it just results in bad predictions it
  wasn't wrong enough to notice. Well, the researchers noticed and also
  realized that thus bug undermined a bunch of existing indirect branch
  mitigations.

  Thus the unusually wide impact on this one. Details:

  ITS is a bug in some Intel CPUs that affects indirect branches
  including RETs in the first half of a cacheline. Due to ITS such
  branches may get wrongly predicted to a target of (direct or indirect)
  branch that is located in the second half of a cacheline. Researchers
  at VUSec found this behavior and reported to Intel.

  Affected processors:

   - Cascade Lake, Cooper Lake, Whiskey Lake V, Coffee Lake R, Comet
     Lake, Ice Lake, Tiger Lake and Rocket Lake.

  Scope of impact:

   - Guest/host isolation:

     When eIBRS is used for guest/host isolation, the indirect branches
     in the VMM may still be predicted with targets corresponding to
     direct branches in the guest.

   - Intra-mode using cBPF:

     cBPF can be used to poison the branch history to exploit ITS.
     Realigning the indirect branches and RETs mitigates this attack
     vector.

   - User/kernel:

     With eIBRS enabled user/kernel isolation is *not* impacted by ITS.

   - Indirect Branch Prediction Barrier (IBPB):

     Due to this bug indirect branches may be predicted with targets
     corresponding to direct branches which were executed prior to IBPB.
     This will be fixed in the microcode.

  Mitigation:

  As indirect branches in the first half of cacheline are affected, the
  mitigation is to replace those indirect branches with a call to thunk that
  is aligned to the second half of the cacheline.

  RETs that take prediction from RSB are not affected, but they may be
  affected by RSB-underflow condition. So, RETs in the first half of
  cacheline are also patched to a return thunk that executes the RET aligned
  to second half of cacheline"

* tag 'its-for-linus-20250509' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  selftest/x86/bugs: Add selftests for ITS
  x86/its: FineIBT-paranoid vs ITS
  x86/its: Use dynamic thunks for indirect branches
  x86/ibt: Keep IBT disabled during alternative patching
  mm/execmem: Unify early execmem_cache behaviour
  x86/its: Align RETs in BHB clear sequence to avoid thunking
  x86/its: Add support for RSB stuffing mitigation
  x86/its: Add "vmexit" option to skip mitigation on some CPUs
  x86/its: Enable Indirect Target Selection mitigation
  x86/its: Add support for ITS-safe return thunk
  x86/its: Add support for ITS-safe indirect thunk
  x86/its: Enumerate Indirect Target Selection (ITS) bug
  Documentation: x86/bugs/its: Add ITS documentation
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 ITS mitigation from Dave Hansen:
 "Mitigate Indirect Target Selection (ITS) issue.

  I'd describe this one as a good old CPU bug where the behavior is
  _obviously_ wrong, but since it just results in bad predictions it
  wasn't wrong enough to notice. Well, the researchers noticed and also
  realized that thus bug undermined a bunch of existing indirect branch
  mitigations.

  Thus the unusually wide impact on this one. Details:

  ITS is a bug in some Intel CPUs that affects indirect branches
  including RETs in the first half of a cacheline. Due to ITS such
  branches may get wrongly predicted to a target of (direct or indirect)
  branch that is located in the second half of a cacheline. Researchers
  at VUSec found this behavior and reported to Intel.

  Affected processors:

   - Cascade Lake, Cooper Lake, Whiskey Lake V, Coffee Lake R, Comet
     Lake, Ice Lake, Tiger Lake and Rocket Lake.

  Scope of impact:

   - Guest/host isolation:

     When eIBRS is used for guest/host isolation, the indirect branches
     in the VMM may still be predicted with targets corresponding to
     direct branches in the guest.

   - Intra-mode using cBPF:

     cBPF can be used to poison the branch history to exploit ITS.
     Realigning the indirect branches and RETs mitigates this attack
     vector.

   - User/kernel:

     With eIBRS enabled user/kernel isolation is *not* impacted by ITS.

   - Indirect Branch Prediction Barrier (IBPB):

     Due to this bug indirect branches may be predicted with targets
     corresponding to direct branches which were executed prior to IBPB.
     This will be fixed in the microcode.

  Mitigation:

  As indirect branches in the first half of cacheline are affected, the
  mitigation is to replace those indirect branches with a call to thunk that
  is aligned to the second half of the cacheline.

  RETs that take prediction from RSB are not affected, but they may be
  affected by RSB-underflow condition. So, RETs in the first half of
  cacheline are also patched to a return thunk that executes the RET aligned
  to second half of cacheline"

* tag 'its-for-linus-20250509' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  selftest/x86/bugs: Add selftests for ITS
  x86/its: FineIBT-paranoid vs ITS
  x86/its: Use dynamic thunks for indirect branches
  x86/ibt: Keep IBT disabled during alternative patching
  mm/execmem: Unify early execmem_cache behaviour
  x86/its: Align RETs in BHB clear sequence to avoid thunking
  x86/its: Add support for RSB stuffing mitigation
  x86/its: Add "vmexit" option to skip mitigation on some CPUs
  x86/its: Enable Indirect Target Selection mitigation
  x86/its: Add support for ITS-safe return thunk
  x86/its: Add support for ITS-safe indirect thunk
  x86/its: Enumerate Indirect Target Selection (ITS) bug
  Documentation: x86/bugs/its: Add ITS documentation
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'driver-core-6.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core</title>
<updated>2025-05-10T16:53:11+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-05-10T16:53:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=345030986df8f7712f9e4c00fe61e145c8984ef3'/>
<id>345030986df8f7712f9e4c00fe61e145c8984ef3</id>
<content type='text'>
Pull driver core fix from Greg KH:
 "Here is a single driver core fix for a regression for platform devices
  that is a regression from a change that went into 6.15-rc1 that
  affected Pixel devices. It has been in linux-next for over a week with
  no reported problems"

* tag 'driver-core-6.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core:
  platform: Fix race condition during DMA configure at IOMMU probe time
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull driver core fix from Greg KH:
 "Here is a single driver core fix for a regression for platform devices
  that is a regression from a change that went into 6.15-rc1 that
  affected Pixel devices. It has been in linux-next for over a week with
  no reported problems"

* tag 'driver-core-6.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core:
  platform: Fix race condition during DMA configure at IOMMU probe time
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/its: Enable Indirect Target Selection mitigation</title>
<updated>2025-05-09T20:22:05+00:00</updated>
<author>
<name>Pawan Gupta</name>
<email>pawan.kumar.gupta@linux.intel.com</email>
</author>
<published>2024-06-22T03:23:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f4818881c47fd91fcb6d62373c57c7844e3de1c0'/>
<id>f4818881c47fd91fcb6d62373c57c7844e3de1c0</id>
<content type='text'>
Indirect Target Selection (ITS) is a bug in some pre-ADL Intel CPUs with
eIBRS. It affects prediction of indirect branch and RETs in the
lower half of cacheline. Due to ITS such branches may get wrongly predicted
to a target of (direct or indirect) branch that is located in the upper
half of the cacheline.

Scope of impact
===============

Guest/host isolation
--------------------
When eIBRS is used for guest/host isolation, the indirect branches in the
VMM may still be predicted with targets corresponding to branches in the
guest.

Intra-mode
----------
cBPF or other native gadgets can be used for intra-mode training and
disclosure using ITS.

User/kernel isolation
---------------------
When eIBRS is enabled user/kernel isolation is not impacted.

Indirect Branch Prediction Barrier (IBPB)
-----------------------------------------
After an IBPB, indirect branches may be predicted with targets
corresponding to direct branches which were executed prior to IBPB. This is
mitigated by a microcode update.

Add cmdline parameter indirect_target_selection=off|on|force to control the
mitigation to relocate the affected branches to an ITS-safe thunk i.e.
located in the upper half of cacheline. Also add the sysfs reporting.

When retpoline mitigation is deployed, ITS safe-thunks are not needed,
because retpoline sequence is already ITS-safe. Similarly, when call depth
tracking (CDT) mitigation is deployed (retbleed=stuff), ITS safe return
thunk is not used, as CDT prevents RSB-underflow.

To not overcomplicate things, ITS mitigation is not supported with
spectre-v2 lfence;jmp mitigation. Moreover, it is less practical to deploy
lfence;jmp mitigation on ITS affected parts anyways.

Signed-off-by: Pawan Gupta &lt;pawan.kumar.gupta@linux.intel.com&gt;
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Reviewed-by: Josh Poimboeuf &lt;jpoimboe@kernel.org&gt;
Reviewed-by: Alexandre Chartre &lt;alexandre.chartre@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Indirect Target Selection (ITS) is a bug in some pre-ADL Intel CPUs with
eIBRS. It affects prediction of indirect branch and RETs in the
lower half of cacheline. Due to ITS such branches may get wrongly predicted
to a target of (direct or indirect) branch that is located in the upper
half of the cacheline.

Scope of impact
===============

Guest/host isolation
--------------------
When eIBRS is used for guest/host isolation, the indirect branches in the
VMM may still be predicted with targets corresponding to branches in the
guest.

Intra-mode
----------
cBPF or other native gadgets can be used for intra-mode training and
disclosure using ITS.

User/kernel isolation
---------------------
When eIBRS is enabled user/kernel isolation is not impacted.

Indirect Branch Prediction Barrier (IBPB)
-----------------------------------------
After an IBPB, indirect branches may be predicted with targets
corresponding to direct branches which were executed prior to IBPB. This is
mitigated by a microcode update.

Add cmdline parameter indirect_target_selection=off|on|force to control the
mitigation to relocate the affected branches to an ITS-safe thunk i.e.
located in the upper half of cacheline. Also add the sysfs reporting.

When retpoline mitigation is deployed, ITS safe-thunks are not needed,
because retpoline sequence is already ITS-safe. Similarly, when call depth
tracking (CDT) mitigation is deployed (retbleed=stuff), ITS safe return
thunk is not used, as CDT prevents RSB-underflow.

To not overcomplicate things, ITS mitigation is not supported with
spectre-v2 lfence;jmp mitigation. Moreover, it is less practical to deploy
lfence;jmp mitigation on ITS affected parts anyways.

Signed-off-by: Pawan Gupta &lt;pawan.kumar.gupta@linux.intel.com&gt;
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Reviewed-by: Josh Poimboeuf &lt;jpoimboe@kernel.org&gt;
Reviewed-by: Alexandre Chartre &lt;alexandre.chartre@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>platform: Fix race condition during DMA configure at IOMMU probe time</title>
<updated>2025-05-01T16:00:58+00:00</updated>
<author>
<name>Will McVicker</name>
<email>willmcvicker@google.com</email>
</author>
<published>2025-04-24T18:04:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=95deee37a12364f410d22c6a8383f59738a2fef3'/>
<id>95deee37a12364f410d22c6a8383f59738a2fef3</id>
<content type='text'>
To avoid a race between the IOMMU probing thread and the device driver
async probing thread during configuration of the platform DMA, update
`platform_dma_configure()` to read `dev-&gt;driver` once and test if it's
NULL before using it. This ensures that we don't de-reference an invalid
platform driver pointer if the device driver is asynchronously bound
while configuring the DMA.

Fixes: bcb81ac6ae3c ("iommu: Get DT/ACPI parsing into the proper probe path")
Signed-off-by: Will McVicker &lt;willmcvicker@google.com&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Link: https://lore.kernel.org/r/20250424180420.3928523-1-willmcvicker@google.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>
To avoid a race between the IOMMU probing thread and the device driver
async probing thread during configuration of the platform DMA, update
`platform_dma_configure()` to read `dev-&gt;driver` once and test if it's
NULL before using it. This ensures that we don't de-reference an invalid
platform driver pointer if the device driver is asynchronously bound
while configuring the DMA.

Fixes: bcb81ac6ae3c ("iommu: Get DT/ACPI parsing into the proper probe path")
Signed-off-by: Will McVicker &lt;willmcvicker@google.com&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Link: https://lore.kernel.org/r/20250424180420.3928523-1-willmcvicker@google.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'modules-6.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux</title>
<updated>2025-04-30T15:37:52+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-04-30T15:37:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3929527918ffa6a0e5c31004ed06d8d1032fc1cf'/>
<id>3929527918ffa6a0e5c31004ed06d8d1032fc1cf</id>
<content type='text'>
Pull modules fixes from Petr Pavlu:
 "A single series to properly handle the module_kobject creation.

  This fixes a problem with missing /sys/module/&lt;module&gt;/drivers for
  built-in modules"

* tag 'modules-6.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux:
  drivers: base: handle module_kobject creation
  kernel: globalize lookup_or_create_module_kobject()
  kernel: refactor lookup_or_create_module_kobject()
  kernel: param: rename locate_module_kobject
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull modules fixes from Petr Pavlu:
 "A single series to properly handle the module_kobject creation.

  This fixes a problem with missing /sys/module/&lt;module&gt;/drivers for
  built-in modules"

* tag 'modules-6.15-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux:
  drivers: base: handle module_kobject creation
  kernel: globalize lookup_or_create_module_kobject()
  kernel: refactor lookup_or_create_module_kobject()
  kernel: param: rename locate_module_kobject
</pre>
</div>
</content>
</entry>
</feed>
