<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/linux, branch v6.18.30</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>printk: add print_hex_dump_devel()</title>
<updated>2026-05-14T13:30:25+00:00</updated>
<author>
<name>Thorsten Blum</name>
<email>thorsten.blum@linux.dev</email>
</author>
<published>2026-05-09T21:29:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ef63ef44e86c64a3c1260c2b67b122d9f82e315e'/>
<id>ef63ef44e86c64a3c1260c2b67b122d9f82e315e</id>
<content type='text'>
[ Upstream commit d134feeb5df33fbf77f482f52a366a44642dba09 ]

Add print_hex_dump_devel() as the hex dump equivalent of pr_devel(),
which emits output only when DEBUG is enabled, but keeps call sites
compiled otherwise.

Suggested-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Thorsten Blum &lt;thorsten.blum@linux.dev&gt;
Reviewed-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Stable-dep-of: 177730a273b1 ("crypto: caam - guard HMAC key hex dumps in hash_digest_key")
Signed-off-by: Sasha Levin &lt;sashal@kernel.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>
[ Upstream commit d134feeb5df33fbf77f482f52a366a44642dba09 ]

Add print_hex_dump_devel() as the hex dump equivalent of pr_devel(),
which emits output only when DEBUG is enabled, but keeps call sites
compiled otherwise.

Suggested-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Thorsten Blum &lt;thorsten.blum@linux.dev&gt;
Reviewed-by: John Ogness &lt;john.ogness@linutronix.de&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Stable-dep-of: 177730a273b1 ("crypto: caam - guard HMAC key hex dumps in hash_digest_key")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>firmware: exynos-acpm: Drop fake 'const' on handle pointer</title>
<updated>2026-05-14T13:30:25+00:00</updated>
<author>
<name>Krzysztof Kozlowski</name>
<email>krzysztof.kozlowski@oss.qualcomm.com</email>
</author>
<published>2026-05-08T14:52:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=23b814ec96a86f6687dc6ffa5d105bc86e7c8505'/>
<id>23b814ec96a86f6687dc6ffa5d105bc86e7c8505</id>
<content type='text'>
[ Upstream commit a2be37eedb52ea26938fa4cc9de1ff84963c57ad ]

All the functions operating on the 'handle' pointer are claiming it is a
pointer to const thus they should not modify the handle.  In fact that's
a false statement, because first thing these functions do is drop the
cast to const with container_of:

  struct acpm_info *acpm = handle_to_acpm_info(handle);

And with such cast the handle is easily writable with simple:

  acpm-&gt;handle.ops.pmic_ops.read_reg = NULL;

The code is not correct logically, either, because functions like
acpm_get_by_node() and acpm_handle_put() are meant to modify the handle
reference counting, thus they must modify the handle.  Modification here
happens anyway, even if the reference counting is stored in the
container which the handle is part of.

The code does not have actual visible bug, but incorrect 'const'
annotations could lead to incorrect compiler decisions.

Fixes: a88927b534ba ("firmware: add Exynos ACPM protocol driver")
Cc: stable@vger.kernel.org
Signed-off-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@oss.qualcomm.com&gt;
Link: https://patch.msgid.link/20260224104203.42950-2-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Krzysztof Kozlowski &lt;krzk@kernel.org&gt;
[ dropped hunks for DVFS/clk-acpm files and `acpm_dvfs_ops` struct that don't exist in 6.18 ]
Signed-off-by: Sasha Levin &lt;sashal@kernel.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>
[ Upstream commit a2be37eedb52ea26938fa4cc9de1ff84963c57ad ]

All the functions operating on the 'handle' pointer are claiming it is a
pointer to const thus they should not modify the handle.  In fact that's
a false statement, because first thing these functions do is drop the
cast to const with container_of:

  struct acpm_info *acpm = handle_to_acpm_info(handle);

And with such cast the handle is easily writable with simple:

  acpm-&gt;handle.ops.pmic_ops.read_reg = NULL;

The code is not correct logically, either, because functions like
acpm_get_by_node() and acpm_handle_put() are meant to modify the handle
reference counting, thus they must modify the handle.  Modification here
happens anyway, even if the reference counting is stored in the
container which the handle is part of.

The code does not have actual visible bug, but incorrect 'const'
annotations could lead to incorrect compiler decisions.

Fixes: a88927b534ba ("firmware: add Exynos ACPM protocol driver")
Cc: stable@vger.kernel.org
Signed-off-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@oss.qualcomm.com&gt;
Link: https://patch.msgid.link/20260224104203.42950-2-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Krzysztof Kozlowski &lt;krzk@kernel.org&gt;
[ dropped hunks for DVFS/clk-acpm files and `acpm_dvfs_ops` struct that don't exist in 6.18 ]
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: core: Optimize time for secure erase/trim for some Kingston eMMCs</title>
<updated>2026-05-14T13:30:25+00:00</updated>
<author>
<name>Luke Wang</name>
<email>ziniu.wang_1@nxp.com</email>
</author>
<published>2026-05-05T10:17:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=afece4e3f2cd57bb4eef8c80ea02eeaa900063e2'/>
<id>afece4e3f2cd57bb4eef8c80ea02eeaa900063e2</id>
<content type='text'>
[ Upstream commit d6bf2e64dec87322f2b11565ddb59c0e967f96e3 ]

Kingston eMMC IY2964 and IB2932 takes a fixed ~2 seconds for each secure
erase/trim operation regardless of size - that is, a single secure
erase/trim operation of 1MB takes the same time as 1GB. With default
calculated 3.5MB max discard size, secure erase 1GB requires ~300 separate
operations taking ~10 minutes total.

Add a card quirk, MMC_QUIRK_FIXED_SECURE_ERASE_TRIM_TIME, to set maximum
secure erase size for those devices. This allows 1GB secure erase to
complete in a single operation, reducing time from 10 minutes to just 2
seconds.

Signed-off-by: Luke Wang &lt;ziniu.wang_1@nxp.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.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>
[ Upstream commit d6bf2e64dec87322f2b11565ddb59c0e967f96e3 ]

Kingston eMMC IY2964 and IB2932 takes a fixed ~2 seconds for each secure
erase/trim operation regardless of size - that is, a single secure
erase/trim operation of 1MB takes the same time as 1GB. With default
calculated 3.5MB max discard size, secure erase 1GB requires ~300 separate
operations taking ~10 minutes total.

Add a card quirk, MMC_QUIRK_FIXED_SECURE_ERASE_TRIM_TIME, to set maximum
secure erase size for those devices. This allows 1GB secure erase to
complete in a single operation, reducing time from 10 minutes to just 2
seconds.

Signed-off-by: Luke Wang &lt;ziniu.wang_1@nxp.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: core: Add quirk for incorrect manufacturing date</title>
<updated>2026-05-14T13:30:25+00:00</updated>
<author>
<name>Avri Altman</name>
<email>avri.altman@sandisk.com</email>
</author>
<published>2026-05-05T10:17:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f597ab044bea75601ce00f694d3e12d1476c2d68'/>
<id>f597ab044bea75601ce00f694d3e12d1476c2d68</id>
<content type='text'>
[ Upstream commit 263ff314cc5602599d481b0912a381555fcbad28 ]

Some eMMC vendors need to report manufacturing dates beyond 2025 but are
reluctant to update the EXT_CSD revision from 8 to 9. Changing the
Updating the EXT_CSD revision may involve additional testing or
qualification steps with customers. To ease this transition and avoid a
full re-qualification process, a workaround is needed. This
patch introduces a temporary quirk that re-purposes the year codes
corresponding to 2010, 2011, and 2012 to represent the years 2026, 2027,
and 2028, respectively. This solution is only valid for this three-year
period.

After 2028, vendors must update their firmware to set EXT_CSD_REV=9 to
continue reporting the correct manufacturing date in compliance with the
JEDEC standard.

The `MMC_QUIRK_BROKEN_MDT` is introduced and enabled for all Sandisk
devices to handle this behavior.

Signed-off-by: Avri Altman &lt;avri.altman@sandisk.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Stable-dep-of: d6bf2e64dec8 ("mmc: core: Optimize time for secure erase/trim for some Kingston eMMCs")
Signed-off-by: Sasha Levin &lt;sashal@kernel.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>
[ Upstream commit 263ff314cc5602599d481b0912a381555fcbad28 ]

Some eMMC vendors need to report manufacturing dates beyond 2025 but are
reluctant to update the EXT_CSD revision from 8 to 9. Changing the
Updating the EXT_CSD revision may involve additional testing or
qualification steps with customers. To ease this transition and avoid a
full re-qualification process, a workaround is needed. This
patch introduces a temporary quirk that re-purposes the year codes
corresponding to 2010, 2011, and 2012 to represent the years 2026, 2027,
and 2028, respectively. This solution is only valid for this three-year
period.

After 2028, vendors must update their firmware to set EXT_CSD_REV=9 to
continue reporting the correct manufacturing date in compliance with the
JEDEC standard.

The `MMC_QUIRK_BROKEN_MDT` is introduced and enabled for all Sandisk
devices to handle this behavior.

Signed-off-by: Avri Altman &lt;avri.altman@sandisk.com&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Stable-dep-of: d6bf2e64dec8 ("mmc: core: Optimize time for secure erase/trim for some Kingston eMMCs")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dma-mapping: add __dma_from_device_group_begin()/end()</title>
<updated>2026-05-14T13:30:25+00:00</updated>
<author>
<name>Michael S. Tsirkin</name>
<email>mst@redhat.com</email>
</author>
<published>2026-05-05T00:15:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=609936df7ce11ef3398b4b3db89ffcf849cb8f93'/>
<id>609936df7ce11ef3398b4b3db89ffcf849cb8f93</id>
<content type='text'>
[ Upstream commit ca085faabb42c31ee204235facc5a430cb9e78a9 ]

When a structure contains a buffer that DMA writes to alongside fields
that the CPU writes to, cache line sharing between the DMA buffer and
CPU-written fields can cause data corruption on non-cache-coherent
platforms.

Add __dma_from_device_group_begin()/end() annotations to ensure proper
alignment to prevent this:

struct my_device {
	spinlock_t lock1;
	__dma_from_device_group_begin();
	char dma_buffer1[16];
	char dma_buffer2[16];
	__dma_from_device_group_end();
	spinlock_t lock2;
};

Message-ID: &lt;19163086d5e4704c316f18f6da06bc1c72968904.1767601130.git.mst@redhat.com&gt;
Acked-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Reviewed-by: Petr Tesarik &lt;ptesarik@suse.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Stable-dep-of: 3023c050af36 ("hwmon: (powerz) Avoid cacheline sharing for DMA buffer")
Signed-off-by: Sasha Levin &lt;sashal@kernel.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>
[ Upstream commit ca085faabb42c31ee204235facc5a430cb9e78a9 ]

When a structure contains a buffer that DMA writes to alongside fields
that the CPU writes to, cache line sharing between the DMA buffer and
CPU-written fields can cause data corruption on non-cache-coherent
platforms.

Add __dma_from_device_group_begin()/end() annotations to ensure proper
alignment to prevent this:

struct my_device {
	spinlock_t lock1;
	__dma_from_device_group_begin();
	char dma_buffer1[16];
	char dma_buffer2[16];
	__dma_from_device_group_end();
	spinlock_t lock2;
};

Message-ID: &lt;19163086d5e4704c316f18f6da06bc1c72968904.1767601130.git.mst@redhat.com&gt;
Acked-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Reviewed-by: Petr Tesarik &lt;ptesarik@suse.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Stable-dep-of: 3023c050af36 ("hwmon: (powerz) Avoid cacheline sharing for DMA buffer")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info</title>
<updated>2026-05-14T13:30:25+00:00</updated>
<author>
<name>Thomas Zimmermann</name>
<email>tzimmermann@suse.de</email>
</author>
<published>2026-05-04T14:19:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=25c2b77bc463f29ee71a54b883548baf9386a0db'/>
<id>25c2b77bc463f29ee71a54b883548baf9386a0db</id>
<content type='text'>
[ Upstream commit 9ded47ad003f09a94b6a710b5c47f4aa5ceb7429 ]

Hold state of deferred I/O in struct fb_deferred_io_state. Allocate an
instance as part of initializing deferred I/O and remove it only after
the final mapping has been closed. If the fb_info and the contained
deferred I/O meanwhile goes away, clear struct fb_deferred_io_state.info
to invalidate the mapping. Any access will then result in a SIGBUS
signal.

Fixes a long-standing problem, where a device hot-unplug happens while
user space still has an active mapping of the graphics memory. The hot-
unplug frees the instance of struct fb_info. Accessing the memory will
operate on undefined state.

Signed-off-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Fixes: 60b59beafba8 ("fbdev: mm: Deferred IO support")
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: stable@vger.kernel.org # v2.6.22+
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
[ replaced kzalloc_obj(*fbdefio_state) with kzalloc(sizeof(*fbdefio_state), GFP_KERNEL) ]
Signed-off-by: Sasha Levin &lt;sashal@kernel.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>
[ Upstream commit 9ded47ad003f09a94b6a710b5c47f4aa5ceb7429 ]

Hold state of deferred I/O in struct fb_deferred_io_state. Allocate an
instance as part of initializing deferred I/O and remove it only after
the final mapping has been closed. If the fb_info and the contained
deferred I/O meanwhile goes away, clear struct fb_deferred_io_state.info
to invalidate the mapping. Any access will then result in a SIGBUS
signal.

Fixes a long-standing problem, where a device hot-unplug happens while
user space still has an active mapping of the graphics memory. The hot-
unplug frees the instance of struct fb_info. Accessing the memory will
operate on undefined state.

Signed-off-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Fixes: 60b59beafba8 ("fbdev: mm: Deferred IO support")
Cc: Helge Deller &lt;deller@gmx.de&gt;
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: stable@vger.kernel.org # v2.6.22+
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
[ replaced kzalloc_obj(*fbdefio_state) with kzalloc(sizeof(*fbdefio_state), GFP_KERNEL) ]
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fanotify: fix false positive on permission events</title>
<updated>2026-05-14T13:30:15+00:00</updated>
<author>
<name>Miklos Szeredi</name>
<email>mszeredi@redhat.com</email>
</author>
<published>2026-04-10T14:49:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7baa02b0ae9d17ec5f08836d8ea88ce1927d0678'/>
<id>7baa02b0ae9d17ec5f08836d8ea88ce1927d0678</id>
<content type='text'>
commit 7746e3bd4cc19b5092e00d32d676e329bfcb6900 upstream.

fsnotify_get_mark_safe() may return false for a mark on an unrelated group,
which results in bypassing the permission check.

Fix by skipping over detached marks that are not in the current group.

CC: stable@vger.kernel.org
Fixes: abc77577a669 ("fsnotify: Provide framework for dropping SRCU lock in -&gt;handle_event")
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Link: https://patch.msgid.link/20260410144950.156160-1-mszeredi@redhat.com
Signed-off-by: Jan Kara &lt;jack@suse.cz&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 7746e3bd4cc19b5092e00d32d676e329bfcb6900 upstream.

fsnotify_get_mark_safe() may return false for a mark on an unrelated group,
which results in bypassing the permission check.

Fix by skipping over detached marks that are not in the current group.

CC: stable@vger.kernel.org
Fixes: abc77577a669 ("fsnotify: Provide framework for dropping SRCU lock in -&gt;handle_event")
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Link: https://patch.msgid.link/20260410144950.156160-1-mszeredi@redhat.com
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>driver core: Add kernel-doc for DEV_FLAG_COUNT enum value</title>
<updated>2026-05-07T04:12:01+00:00</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2026-04-14T02:59:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b8c5acce56e07eb6654d0ff0427945875d9179f8'/>
<id>b8c5acce56e07eb6654d0ff0427945875d9179f8</id>
<content type='text'>
commit 5b484311507b5d403c1f7a45f6aa3778549e268b upstream.

Even though nobody should use this value (except when declaring the
"flags" bitmap), kernel-doc still gets upset that it's not documented.
It reports:

  WARNING: ../include/linux/device.h:519
  Enum value 'DEV_FLAG_COUNT' not described in enum 'struct_device_flags'

Add the description of DEV_FLAG_COUNT.

Fixes: a2225b6e834a ("driver core: Don't let a device probe until it's ready")
Reported-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Closes: https://lore.kernel.org/f318cd43-81fd-48b9-abf7-92af85f12f91@infradead.org
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Tested-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Reviewed-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Link: https://patch.msgid.link/20260413195910.1.I23aca74fe2d3636a47df196a80920fecb2643220@changeid
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.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 5b484311507b5d403c1f7a45f6aa3778549e268b upstream.

Even though nobody should use this value (except when declaring the
"flags" bitmap), kernel-doc still gets upset that it's not documented.
It reports:

  WARNING: ../include/linux/device.h:519
  Enum value 'DEV_FLAG_COUNT' not described in enum 'struct_device_flags'

Add the description of DEV_FLAG_COUNT.

Fixes: a2225b6e834a ("driver core: Don't let a device probe until it's ready")
Reported-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Closes: https://lore.kernel.org/f318cd43-81fd-48b9-abf7-92af85f12f91@infradead.org
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Tested-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Reviewed-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Link: https://patch.msgid.link/20260413195910.1.I23aca74fe2d3636a47df196a80920fecb2643220@changeid
Signed-off-by: Danilo Krummrich &lt;dakr@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: prevent droppable mappings from being locked</title>
<updated>2026-05-07T04:11:59+00:00</updated>
<author>
<name>Anthony Yznaga</name>
<email>anthony.yznaga@oracle.com</email>
</author>
<published>2026-04-28T20:05:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6f977b0472f700e4bcb981342ceacf2f1b1a3671'/>
<id>6f977b0472f700e4bcb981342ceacf2f1b1a3671</id>
<content type='text'>
[ Upstream commit d239462787b072c78eb19fc1f155c3d411256282 ]

Droppable mappings must not be lockable.  There is a check for VMAs with
VM_DROPPABLE set in mlock_fixup() along with checks for other types of
unlockable VMAs which ensures this when calling mlock()/mlock2().

For mlockall(MCL_FUTURE), the check for unlockable VMAs is different.  In
apply_mlockall_flags(), if the flags parameter has MCL_FUTURE set, the
current task's mm's default VMA flag field mm-&gt;def_flags has VM_LOCKED
applied to it.  VM_LOCKONFAULT is also applied if MCL_ONFAULT is also set.
When these flags are set as default in this manner they are cleared in
__mmap_complete() for new mappings that do not support mlock.  A check for
VM_DROPPABLE in __mmap_complete() is missing resulting in droppable
mappings created with VM_LOCKED set.  To fix this and reduce that chance
of similar bugs in the future, introduce and use vma_supports_mlock().

Link: https://lkml.kernel.org/r/20260310155821.17869-1-anthony.yznaga@oracle.com
Fixes: 9651fcedf7b9 ("mm: add MAP_DROPPABLE for designating always lazily freeable mappings")
Signed-off-by: Anthony Yznaga &lt;anthony.yznaga@oracle.com&gt;
Suggested-by: David Hildenbrand &lt;david@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Reviewed-by: Pedro Falcato &lt;pfalcato@suse.de&gt;
Reviewed-by: Lorenzo Stoakes (Oracle) &lt;ljs@kernel.org&gt;
Tested-by: Lorenzo Stoakes (Oracle) &lt;ljs@kernel.org&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Jason A. Donenfeld &lt;jason@zx2c4.com&gt;
Cc: Liam Howlett &lt;liam.howlett@oracle.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Shuah Khan &lt;shuah@kernel.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
[ added const to is_vm_hugetlb_page and stubbed vma_supports_mlock in vma_internal.h instead of the split-out stubs.h ]
Signed-off-by: Sasha Levin &lt;sashal@kernel.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>
[ Upstream commit d239462787b072c78eb19fc1f155c3d411256282 ]

Droppable mappings must not be lockable.  There is a check for VMAs with
VM_DROPPABLE set in mlock_fixup() along with checks for other types of
unlockable VMAs which ensures this when calling mlock()/mlock2().

For mlockall(MCL_FUTURE), the check for unlockable VMAs is different.  In
apply_mlockall_flags(), if the flags parameter has MCL_FUTURE set, the
current task's mm's default VMA flag field mm-&gt;def_flags has VM_LOCKED
applied to it.  VM_LOCKONFAULT is also applied if MCL_ONFAULT is also set.
When these flags are set as default in this manner they are cleared in
__mmap_complete() for new mappings that do not support mlock.  A check for
VM_DROPPABLE in __mmap_complete() is missing resulting in droppable
mappings created with VM_LOCKED set.  To fix this and reduce that chance
of similar bugs in the future, introduce and use vma_supports_mlock().

Link: https://lkml.kernel.org/r/20260310155821.17869-1-anthony.yznaga@oracle.com
Fixes: 9651fcedf7b9 ("mm: add MAP_DROPPABLE for designating always lazily freeable mappings")
Signed-off-by: Anthony Yznaga &lt;anthony.yznaga@oracle.com&gt;
Suggested-by: David Hildenbrand &lt;david@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Reviewed-by: Pedro Falcato &lt;pfalcato@suse.de&gt;
Reviewed-by: Lorenzo Stoakes (Oracle) &lt;ljs@kernel.org&gt;
Tested-by: Lorenzo Stoakes (Oracle) &lt;ljs@kernel.org&gt;
Cc: Jann Horn &lt;jannh@google.com&gt;
Cc: Jason A. Donenfeld &lt;jason@zx2c4.com&gt;
Cc: Liam Howlett &lt;liam.howlett@oracle.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Shuah Khan &lt;shuah@kernel.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Cc: Vlastimil Babka &lt;vbabka@kernel.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
[ added const to is_vm_hugetlb_page and stubbed vma_supports_mlock in vma_internal.h instead of the split-out stubs.h ]
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>randomize_kstack: Maintain kstack_offset per task</title>
<updated>2026-05-07T04:11:47+00:00</updated>
<author>
<name>Ryan Roberts</name>
<email>ryan.roberts@arm.com</email>
</author>
<published>2026-03-03T15:08:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d780f24a4939862e1df9def415fe7de59280fc7c'/>
<id>d780f24a4939862e1df9def415fe7de59280fc7c</id>
<content type='text'>
commit 37beb42560165869838e7d91724f3e629db64129 upstream.

kstack_offset was previously maintained per-cpu, but this caused a
couple of issues. So let's instead make it per-task.

Issue 1: add_random_kstack_offset() and choose_random_kstack_offset()
expected and required to be called with interrupts and preemption
disabled so that it could manipulate per-cpu state. But arm64, loongarch
and risc-v are calling them with interrupts and preemption enabled. I
don't _think_ this causes any functional issues, but it's certainly
unexpected and could lead to manipulating the wrong cpu's state, which
could cause a minor performance degradation due to bouncing the cache
lines. By maintaining the state per-task those functions can safely be
called in preemptible context.

Issue 2: add_random_kstack_offset() is called before executing the
syscall and expands the stack using a previously chosen random offset.
choose_random_kstack_offset() is called after executing the syscall and
chooses and stores a new random offset for the next syscall. With
per-cpu storage for this offset, an attacker could force cpu migration
during the execution of the syscall and prevent the offset from being
updated for the original cpu such that it is predictable for the next
syscall on that cpu. By maintaining the state per-task, this problem
goes away because the per-task random offset is updated after the
syscall regardless of which cpu it is executing on.

Fixes: 39218ff4c625 ("stack: Optionally randomize kernel stack offset each syscall")
Closes: https://lore.kernel.org/all/dd8c37bc-795f-4c7a-9086-69e584d8ab24@arm.com/
Cc: stable@vger.kernel.org
Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Link: https://patch.msgid.link/20260303150840.3789438-2-ryan.roberts@arm.com
Signed-off-by: Kees Cook &lt;kees@kernel.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 37beb42560165869838e7d91724f3e629db64129 upstream.

kstack_offset was previously maintained per-cpu, but this caused a
couple of issues. So let's instead make it per-task.

Issue 1: add_random_kstack_offset() and choose_random_kstack_offset()
expected and required to be called with interrupts and preemption
disabled so that it could manipulate per-cpu state. But arm64, loongarch
and risc-v are calling them with interrupts and preemption enabled. I
don't _think_ this causes any functional issues, but it's certainly
unexpected and could lead to manipulating the wrong cpu's state, which
could cause a minor performance degradation due to bouncing the cache
lines. By maintaining the state per-task those functions can safely be
called in preemptible context.

Issue 2: add_random_kstack_offset() is called before executing the
syscall and expands the stack using a previously chosen random offset.
choose_random_kstack_offset() is called after executing the syscall and
chooses and stores a new random offset for the next syscall. With
per-cpu storage for this offset, an attacker could force cpu migration
during the execution of the syscall and prevent the offset from being
updated for the original cpu such that it is predictable for the next
syscall on that cpu. By maintaining the state per-task, this problem
goes away because the per-task random offset is updated after the
syscall regardless of which cpu it is executing on.

Fixes: 39218ff4c625 ("stack: Optionally randomize kernel stack offset each syscall")
Closes: https://lore.kernel.org/all/dd8c37bc-795f-4c7a-9086-69e584d8ab24@arm.com/
Cc: stable@vger.kernel.org
Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Ryan Roberts &lt;ryan.roberts@arm.com&gt;
Link: https://patch.msgid.link/20260303150840.3789438-2-ryan.roberts@arm.com
Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
