linux-stable.git/include, branch v7.0.4

driver core: Add kernel-doc for DEV_FLAG_COUNT enum value

2026-05-07T04:14:16+00:00

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 
Closes: https://lore.kernel.org/f318cd43-81fd-48b9-abf7-92af85f12f91@infradead.org
Signed-off-by: Douglas Anderson 
Tested-by: Randy Dunlap 
Reviewed-by: Randy Dunlap 
Link: https://patch.msgid.link/20260413195910.1.I23aca74fe2d3636a47df196a80920fecb2643220@changeid
Signed-off-by: Danilo Krummrich 
Signed-off-by: Greg Kroah-Hartman

mm: various small mmap_prepare cleanups

2026-05-07T04:14:15+00:00

[ Upstream commit 3e4bb2706817710d9461394da8b75be79981586b ]

Patch series "mm: expand mmap_prepare functionality and usage", v4.

This series expands the mmap_prepare functionality, which is intended to
replace the deprecated f_op->mmap hook which has been the source of bugs
and security issues for some time.

This series starts with some cleanup of existing mmap_prepare logic, then
adds documentation for the mmap_prepare call to make it easier for
filesystem and driver writers to understand how it works.

It then importantly adds a vm_ops->mapped hook, a key feature that was
missing from mmap_prepare previously - this is invoked when a driver which
specifies mmap_prepare has successfully been mapped but not merged with
another VMA.

mmap_prepare is invoked prior to a merge being attempted, so you cannot
manipulate state such as reference counts as if it were a new mapping.

The vm_ops->mapped hook allows a driver to perform tasks required at this
stage, and provides symmetry against subsequent vm_ops->open,close calls.

The series uses this to correct the afs implementation which wrongly
manipulated reference count at mmap_prepare time.

It then adds an mmap_prepare equivalent of vm_iomap_memory() -
mmap_action_simple_ioremap(), then uses this to update a number of drivers.

It then splits out the mmap_prepare compatibility layer (which allows for
invocation of mmap_prepare hooks in an mmap() hook) in such a way as to
allow for more incremental implementation of mmap_prepare hooks.

It then uses this to extend mmap_prepare usage in drivers.

Finally it adds an mmap_prepare equivalent of vm_map_pages(), which lays
the foundation for future work which will extend mmap_prepare to DMA
coherent mappings.

This patch (of 21):

Rather than passing arbitrary fields, pass a vm_area_desc pointer to mmap
prepare functions to mmap prepare, and an action and vma pointer to mmap
complete in order to put all the action-specific logic in the function
actually doing the work.

Additionally, allow mmap prepare functions to return an error so we can
error out as soon as possible if there is something logically incorrect in
the input.

Update remap_pfn_range_prepare() to properly check the input range for the
CoW case.

Also remove io_remap_pfn_range_complete(), as we can simply set up the
fields correctly in io_remap_pfn_range_prepare() and use
remap_pfn_range_complete() for this.

While we're here, make remap_pfn_range_prepare_vma() a little neater, and
pass mmap_action directly to call_action_complete().

Then, update compat_vma_mmap() to perform its logic directly, as
__compat_vma_map() is not used by anything so we don't need to export it.

Also update compat_vma_mmap() to use vfs_mmap_prepare() rather than
calling the mmap_prepare op directly.

Finally, update the VMA userland tests to reflect the changes.

Link: https://lkml.kernel.org/r/cover.1774045440.git.ljs@kernel.org
Link: https://lkml.kernel.org/r/99f408e4694f44ab12bdc55fe0bd9685d3bd1117.1774045440.git.ljs@kernel.org
Signed-off-by: Lorenzo Stoakes (Oracle) 
Acked-by: Vlastimil Babka (SUSE) 
Cc: Alexander Shishkin 
Cc: Alexandre Torgue 
Cc: Al Viro 
Cc: Arnd Bergmann 
Cc: Bodo Stroesser 
Cc: Christian Brauner 
Cc: Clemens Ladisch 
Cc: David Hildenbrand 
Cc: David Howells 
Cc: Dexuan Cui 
Cc: Greg Kroah-Hartman 
Cc: Haiyang Zhang 
Cc: Jan Kara 
Cc: Jann Horn 
Cc: Jonathan Corbet 
Cc: K. Y. Srinivasan 
Cc: Liam Howlett 
Cc: Long Li 
Cc: Marc Dionne 
Cc: "Martin K. Petersen" 
Cc: Maxime Coquelin 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Miquel Raynal 
Cc: Pedro Falcato 
Cc: Richard Weinberger 
Cc: Ryan Roberts 
Cc: Suren Baghdasaryan 
Cc: Vignesh Raghavendra 
Cc: Wei Liu 
Signed-off-by: Andrew Morton 
Stable-dep-of: f96e1d5f15b7 ("mm: avoid deadlock when holding rmap on mmap_prepare error")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

firmware: exynos-acpm: Drop fake 'const' on handle pointer

2026-05-07T04:14:02+00:00

commit a2be37eedb52ea26938fa4cc9de1ff84963c57ad upstream.

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->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 
Link: https://patch.msgid.link/20260224104203.42950-2-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: Greg Kroah-Hartman

randomize_kstack: Maintain kstack_offset per task

2026-05-07T04:14:01+00:00

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 
Signed-off-by: Ryan Roberts 
Link: https://patch.msgid.link/20260303150840.3789438-2-ryan.roberts@arm.com
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman

lsm: add backing_file LSM hooks

2026-05-07T04:14:01+00:00

commit 6af36aeb147a06dea47c49859cd6ca5659aeb987 upstream.

Stacked filesystems such as overlayfs do not currently provide the
necessary mechanisms for LSMs to properly enforce access controls on the
mmap() and mprotect() operations.  In order to resolve this gap, a LSM
security blob is being added to the backing_file struct and the following
new LSM hooks are being created:

 security_backing_file_alloc()
 security_backing_file_free()
 security_mmap_backing_file()

The first two hooks are to manage the lifecycle of the LSM security blob
in the backing_file struct, while the third provides a new mmap() access
control point for the underlying backing file.  It is also expected that
LSMs will likely want to update their security_file_mprotect() callback
to address issues with their mprotect() controls, but that does not
require a change to the security_file_mprotect() LSM hook.

There are a three other small changes to support these new LSM hooks:
* Pass the user file associated with a backing file down to
alloc_empty_backing_file() so it can be included in the
security_backing_file_alloc() hook.
* Add getter and setter functions for the backing_file struct LSM blob
as the backing_file struct remains private to fs/file_table.c.
* Constify the file struct field in the LSM common_audit_data struct to
better support LSMs that need to pass a const file struct pointer into
the common LSM audit code.

Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL()
and supplying a fixup.

Cc: stable@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-unionfs@vger.kernel.org
Cc: linux-erofs@lists.ozlabs.org
Reviewed-by: Amir Goldstein 
Reviewed-by: Serge Hallyn 
Reviewed-by: Christian Brauner 
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info

2026-05-07T04:14:00+00:00

commit 9ded47ad003f09a94b6a710b5c47f4aa5ceb7429 upstream.

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 
Fixes: 60b59beafba8 ("fbdev: mm: Deferred IO support")
Cc: Helge Deller 
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 
Signed-off-by: Greg Kroah-Hartman

tpm: avoid -Wunused-but-set-variable

2026-05-07T04:13:59+00:00

commit 6f1d4d2ecfcd1b577dc87350ea965fe81f272e83 upstream.

Outside of the EFI tpm code, the TPM_MEMREMAP()/TPM_MEMUNMAP functions are
defined as trivial macros, leading to the mapping_size variable ending
up unused:

In file included from drivers/char/tpm/tpm-sysfs.c:16:
In file included from drivers/char/tpm/tpm.h:28:
include/linux/tpm_eventlog.h:167:6: error: variable 'mapping_size' set but not used [-Werror,-Wunused-but-set-variable]
  167 |         int mapping_size;

Turn the stubs into inline functions to avoid this warning.

Cc: stable@vger.kernel.org # v5.3+
Fixes: c46f3405692d ("tpm: Reserve the TPM final events table")
Signed-off-by: Arnd Bergmann 
Reviewed-by: Thorsten Blum 
Reviewed-by: Jarkko Sakkinen 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Greg Kroah-Hartman

net: mctp: fix don't require received header reserved bits to be zero

2026-05-07T04:13:58+00:00

commit a663bac71a2f0b3ac6c373168ca57b2a6e6381aa upstream.

From the MCTP Base specification (DSP0236 v1.2.1), the first byte of
the MCTP header contains a 4 bit reserved field, and 4 bit version.

On our current receive path, we require those 4 reserved bits to be
zero, but the 9500-8i card is non-conformant, and may set these
reserved bits.

DSP0236 states that the reserved bits must be written as zero, and
ignored when read. While the device might not conform to the former,
we should accept these message to conform to the latter.

Relax our check on the MCTP version byte to allow non-zero bits in the
reserved field.

Fixes: 889b7da23abf ("mctp: Add initial routing framework")
Signed-off-by: Yuan Zhaoming 
Cc: stable@vger.kernel.org
Acked-by: Jeremy Kerr 
Link: https://patch.msgid.link/20260417141340.5306-1-yuanzhaoming901030@126.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

rxrpc: Fix re-decryption of RESPONSE packets

2026-05-07T04:13:56+00:00

commit 0422e7a4883f25101903f3e8105c0808aa5f4ce9 upstream.

If a RESPONSE packet gets a temporary failure during processing, it may end
up in a partially decrypted state - and then get requeued for a retry.

Fix this by just discarding the packet; we will send another CHALLENGE
packet and thereby elicit a further response.  Similarly, discard an
incoming CHALLENGE packet if we get an error whilst generating a RESPONSE;
the server will send another CHALLENGE.

Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Closes: https://sashiko.dev/#/patchset/20260422161438.2593376-4-dhowells@redhat.com
Signed-off-by: David Howells 
cc: Marc Dionne 
cc: Jeffrey Altman 
cc: Simon Horman 
cc: linux-afs@lists.infradead.org
cc: stable@kernel.org
Link: https://patch.msgid.link/20260423200909.3049438-3-dhowells@redhat.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

rxrpc: Fix rxkad crypto unalignment handling

2026-05-07T04:13:56+00:00

commit def304aae2edf321d2671fd6ca766a93c21f877e upstream.

Fix handling of a packet with a misaligned crypto length.  Also handle
non-ENOMEM errors from decryption by aborting.  Further, remove the
WARN_ON_ONCE() so that it can't be remotely triggered (a trace line can
still be emitted).

Fixes: f93af41b9f5f ("rxrpc: Fix missing error checks for rxkad encryption/decryption failure")
Closes: https://sashiko.dev/#/patchset/20260408121252.2249051-1-dhowells%40redhat.com
Signed-off-by: David Howells 
cc: Marc Dionne 
cc: Jeffrey Altman 
cc: Simon Horman 
cc: linux-afs@lists.infradead.org
cc: stable@kernel.org
Link: https://patch.msgid.link/20260422161438.2593376-3-dhowells@redhat.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman