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Sync updates - #51

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rppt and others added 30 commits July 9, 2026 15:48
Vova Tokarev says:

  userfaultfd allows registration on shadow stack VMAs.  With userfaultfd
  access, you can register on the shadow stack, discard a page ... and
  inject a page with chosen return addresses via UFFDIO_COPY.

Update vma_can_userfault() to reject VM_SHADOW_STACK.

While on it, also reject VM_SPECIAL so that if a driver would implement
vm_uffd_ops, it wouldn't be possible to register special VMAs with
userfaultfd.

Since VM_SPECIAL includes VM_DONTEXPAND which is set but hugetlb, exclude
hugetlb VMAs from the check for VM_SPECIAL.

Link: https://lore.kernel.org/20260618095017.2553004-1-rppt@kernel.org
Fixes: 54007f8 ("mm: Introduce VM_SHADOW_STACK for shadow stack memory")
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reported-by: vova tokarev <vladimirelitokarev@gmail.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
My legal and preferred first names are SeongJae and SJ, respectively.  I
was using the legal name for commits and tags, while using the preferred
name for conversations.  It sometimes confuses people including myself. 
Consistently use the preferred name.

Together remove copyright notes on files.  Those are only confusing for
people who are not familiar with the law.  Meanwhile, we can infer the
information in a better way from git logs and public information.

Link: https://lore.kernel.org/20260630013820.143366-1-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Acked-by: Lorenzo Stoakes <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 65edfda ("mm/rmap: extend rmap and migration support
device-private entries") introduced the concept of device-private PMD
entries, but did not correctly update the rmap walk code to account for
them.

As a result, when page_vma_mapped_walk() encounters device-private PMD
entries, it takes no action other than to acquire the PMD lock and exit.

However this is highly problematic for two reasons - firstly, device
private entries possess a PFN so check_pmd() needs to be called to ensure
an overlapping PFN range.

Secondly, and more importantly, if PVMW_MIGRATION is set the caller
assumes the returned entry is a migration entry, resulting in memory
corruption when the caller tries to interpret the device private entry as
such.

In addition, commit 1462872 ("mm/huge_memory: implement
device-private THP splitting") allowed device private PMDs to be split
like THP mappings, but again did not update this code path.

As a result, we might race a PMD split prior to acquiring the PMD lock.

This patch addresses all of these issues by invoking check_pmd(), ensuring
PMVW_MIGRATION is not set and checks whether a split raced us we do for
PMD THP and migration entries.

Instead of checking for a subset of the cases after taking the pmd_lock(),
put device-private along with pmd_trans_huge() and
pmd_is_migration_entry().  Also remove thp_migration_supported() as it is
already guarded by pmd_is_migration_entry().

[akpm@linux-foundation.org: fix Raspberry Pi 1 build, per David]
Link: https://lore.kernel.org/20260630021540.17297-1-richard.weiyang@gmail.com
Fixes: 65edfda ("mm/rmap: extend rmap and migration support device-private entries")
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Suggested-by: David Hildenbrand <david@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Acked-by: Balbir Singh <balbirs@nvidia.com>
Tested-by: Klara Modin <klarasmodin@gmail.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: <stable@vger.kernel.org>q
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
…tablished

__split_folio_to_order() copies the hwpoison state onto each new sub-folio
while splitting a folio to a non-zero order.  It does so via

	if (handle_hwpoison && page_range_has_hwpoisoned(new_head, new_nr_pages))
		folio_set_has_hwpoisoned(new_folio);

*before* clear_compound_head(new_head)/prep_compound_page(new_head, ...)
turns @new_head from a tail page into a proper folio head.

PG_has_hwpoisoned is a FOLIO_SECOND_PAGE flag, so
folio_set_has_hwpoisoned() resolves to folio_flags(folio, 1).  With the
new compound_info-based page-flags layout, folio_flags() asserts the page
is not a tail:

	VM_BUG_ON_PGFLAGS(page->compound_info & 1, page);
	VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags.f), page);

At the current call site @new_head still has the tail marker
(compound_info bit 0 set, PG_head clear), so on CONFIG_DEBUG_VM kernels
this hits:

  kernel BUG at include/linux/page-flags.h:354
  folio_flags+0x82
  folio_set_has_hwpoisoned
  __split_folio_to_order
  __split_unmapped_folio
  __folio_split
  truncate_inode_partial_folio  (shmem hole-punch / MADV_REMOVE)

Reproduced by syzkaller: hwpoison-inject a few subpages of a large shmem
folio, then MADV_REMOVE (fallocate punch hole) on the same range, which
splits the partial folio to a non-zero order.

memory_failure() tries to split the poisoned folio to order 0 first, but
that split is best-effort; when it fails the folio is left large with
PG_has_hwpoisoned set, the case fa5a061 added this hwpoison copying
for.

Move the folio_set_has_hwpoisoned() call to after
clear_compound_head()/prep_compound_page(), where @new_folio is a real
order-new_order head folio (handle_hwpoison implies new_order != 0, so a
second page always exists).  The flag still lands on the same struct page
(page[1] of the new folio); only the ordering relative to compound-head
setup changes, satisfying the FOLIO_SECOND_PAGE precondition.

Link: https://lore.kernel.org/20260701174235.3173401-1-riel@surriel.com
Fixes: fa5a061 ("mm/huge_memory: preserve PG_has_hwpoisoned if a folio is split to >0 order")
Signed-off-by: Rik van Riel <riel@surriel.com>
Assisted-by: Claude:claude-opus-4-8
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Tested-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The loop in clear_user_pages() iterates over all pages and calls
clear_user_page() for each of them.  During the loop "vaddr" is modified. 
However on m68k clear_user() is a macro which does not use "vaddr".  The
compiler sees a variable which is modified but never used and emits a
warning for that:

include/linux/highmem.h: In function 'clear_user_pages':
include/linux/highmem.h:234:63: warning: parameter 'vaddr' set but not used [-Wunused-but-set-parameter=]
    static inline void clear_user_pages(void *addr, unsigned long vaddr,

Other architectures use an inline function for clear_user_page() which
avoids the warning.  This is not possible on m68k, as dlush_dcache_page()
is another macro which is not yet defined where clear_user_page() is
defined.  Including cacheflush_mm.h will trigger recursive and lots of
other issues.

So hide the warning with a cast to (void) instead.

While we are here, do the same for copy_user_page().

Link: https://lore.kernel.org/20260525-m68k-clear_user_page-v2-1-0c8981c6eca1@weissschuh.net
Fixes: 62a9f5a ("mm: introduce clear_pages() and clear_user_pages()")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON core logic assumes zero length regions don't exist.  However, a few
DAMON API callers including DAMON_SYSFS, DAMON_RECLAIM and DAMON_LRU_SORT
allow users to set empty monitoring target regions.  This could result in
WARN_ONCE() on CONFIG_DAMON_DEBUG_SANITY enabled kernel, and
divide-by-zero from damon_merge_two_regions().

For example, the WANR_ONCE() can be triggered like below.

    # grep DAMON_DEBUG_SANITY /boot/config-$(uname -r)
    # CONFIG_DAMON_DEBUG_SANITY=y
    # damo start
    # cd /sys/kernel/mm/damon/admin/kdamonds/0
    # echo 0 > contexts/0/targets/0/regions/0/start
    # echo 0 > contexts/0/targets/0/regions/0/end
    # echo commit > state
    # dmesg
    [....]
    [   73.705780] ------------[ cut here ]------------
    [   73.707552] start 0 >= end 0
    [   73.708452] WARNING: mm/damon/core.c:359 at damon_new_region+0x6e/0x80, CPU#1: kdamond.0/758
    [...]

All DAMON API callers eventually use damon_set_regions() to setup the
regions.  Add the validation logic in the function.

Link: https://lore.kernel.org/20260630035221.146458-1-sj@kernel.org
Fixes: 43b0536 ("mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)")
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Yang yingliang <yangyingliang@huawei.com>
Cc: <stable@vger.kernel.org> # 5.16.x
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Building the fat kunit tests on with -fsanitize=alignment reveals some
rather excessive stack usage:

fs/fat/fat_test.c: In function 'fat_clus_to_blknr_test':
fs/fat/fat_test.c:33:1: error: the frame size of 4736 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]
   33 | }
      | ^
fs/fat/fat_test.c: In function 'fat_get_blknr_offset_test':
fs/fat/fat_test.c:52:1: error: the frame size of 4800 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]

The problem is clearly related to the on-stack copy of a local
msdos_sb_info structure.  Avoid this by making that copy 'static const'
and changing the called functions to accept a constant input.

Link: https://lore.kernel.org/20260515204456.2692208-1-arnd@kernel.org
Fixes: 410002f ("kunit: fat: test cluster and directory i_pos layout helpers")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Adi Nata <adinata.softwareengineer@gmail.com>
Cc: David Laight <david.laight.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Usama has been active around THP, really enjoys working on THPs, and tries
to review all the patches that come in.

Let's invite him to the THP party as a reviewer to help with the ongoing
THP review load.

Link: https://lore.kernel.org/20260702140257.44780-1-lance.yang@linux.dev
Signed-off-by: Lance Yang <lance.yang@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Lorenzo Stoakes <ljs@kernel.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: Barry Song <baohua@kernel.org>
Acked-by: SJ Park <sj@kernel.org>
Acked-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
damon_set_regions() assumes the input ranges are sorted by the address and
don't overlap each other.  Hence the assumption was initially to be
explicitly validated.  But commit 97d482f ("mm/damon/sysfs: reuse
damon_set_regions() for regions setting") has mistakenly removed the
validation.

This can make DAMON behave in unexpected ways.  At the best, the
monitoring results snapshot will just look weird since there will be
overlapping regions.  DAMOS will also work weirdly, applying the same
action multiple times for overlapping regions, and make DAMOS quota weird.
More seriously, depending on the setup and regions updates sequence,
negative size regions can be made.  It will trigger WARN_ONCE() if the
kernel is built with CONFIG_DAMON_DEBUG_SANITY=y.  Depending on the
monitoring results, the negative size region can further trigger division
by zero in damon_merge_two_regions().

Note that some of the consequences including the WARN_ONCE() and the
divide by zero depend on commits that were introduced after the root cause
commit 97d482f ("mm/damon/sysfs: reuse damon_set_regions() for
regions setting").

Fix the problems by checking the assumption and returning an error if
the input ranges don't meet the assumption.

The issue was discovered [1] by Sashiko.

Link: https://lore.kernel.org/20260703165610.92894-1-sj@kernel.org
Link: https://lore.kernel.org/20260630041806.151124-1-sj@kernel.org [1]
Fixes: 97d482f ("mm/damon/sysfs: reuse damon_set_regions() for regions setting")
Signed-off-by: SJ Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> # 5.19.x
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The per-cpu object checksum folds each CPU's CRC together with XOR and
seeds every CRC with 0.  Both choices make update_checksum() miss content
changes:

  - XOR is self-cancelling, so equal contents on two CPUs cancel out and
    simultaneous identical changes leave the checksum unchanged.
  - crc32(0, ...) over all-zero content is 0, so a freshly allocated,
    zeroed per-cpu area checksums to 0, matching the initial value, and
    the object is never seen to change.

See discussions at [0].

When update_checksum() wrongly reports an actively modified object as
unchanged, kmemleak stops greying it for an extra scan and can report a
live per-cpu object as a leak.

Fold the per-cpu CRC as a single rolling checksum across all CPUs and
initialise the object checksum to ~0 so the first computed value always
registers as a change, even for content that hashes to 0. 
reset_checksum() is seeded the same way.

Link: https://lore.kernel.org/all/akfYImSNDh3OjIfR@gmail.com [0]
Link: https://lore.kernel.org/20260703-kmemleak_checksum-v1-1-5e0ab7d6966f@debian.org
Fixes: 6c99d4e ("kmemleak: enable tracking for percpu pointers")
Signed-off-by: Breno Leitao <leitao@debian.org>
Co-developed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
At the moment, if a virtio balloon device has a page reporting vq but its
size is < PAGE_REPORTING_CAPACITY (32), the balloon driver fails probe.

But, there's no way for host to know this value, so it can easily create a
smaller vq and suddenly adding the reporting capability to the device
makes all of the driver fail.  Not pretty.

Add a capacity field to page_reporting_dev_info so drivers can control the
maximum number of pages per report batch.

In virtio-balloon, set the capacity to the reporting virtqueue size,
letting page_reporting adapt to whatever the device provides.

Capacity need not be a power of two.  Code previously called out division
by PAGE_REPORTING_CAPACITY as cheap since it was a power of 2, but no
performance difference was observed with non-power-of-2 values.

If capacity is 0 or exceeds PAGE_REPORTING_CAPACITY, it defaults to
PAGE_REPORTING_CAPACITY.  The 0 check and the clamping is done in
page_reporting_register(), before the reporting work is scheduled, so we
never get division by 0.

Link: https://lore.kernel.org/444c24cf39f3f3620fc90ef4695bd6b0979f4c4b.1783232420.git.mst@redhat.com
Fixes: b0c504f ("virtio-balloon: add support for providing free page reports to host")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Assisted-by: Claude:claude-opus-4-6
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Gregory Price <gourry@gourry.net>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Eugenio Pérez <eperezma@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 97f0b13 ("tracing: add trace event for memory-failure")
introduced memory_failure_event in ras subsystem.  commit 3180748
("mm/memory-failure: remove the selection of RAS") changed
memory_failure_event to memory_failure subsystem.  This breaks the
backward compatibility, some user programs rely on it.

Change memory_failure_event to ras subsystem to keep backward
compatibility.

Link: https://lore.kernel.org/20260605081213.154660-1-xieyuanbin1@huawei.com
Fixes: 3180748 ("mm/memory-failure: remove the selection of RAS")
Signed-off-by: Xie Yuanbin <xieyuanbin1@huawei.com>
Reported-by: Yi Lai <yi1.lai@intel.com>
Reported-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Closes: https://lore.kernel.org/linux-mm/CY8PR11MB7134346A3E4BB28ECA28D6E989132@CY8PR11MB7134.namprd11.prod.outlook.com
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Tested-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Support for UMC CPUs was removed in

  7d328c5 ("x86/cpu: Remove CPU_SUP_UMC_32 support"),

but a Makefile rule for the support code remained. Remove it.

Fixes: 7d328c5 ("x86/cpu: Remove CPU_SUP_UMC_32 support")
Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ahmed S. Darwish <darwi@linutronix.de>
Link: https://patch.msgid.link/20260610033252.164571-1-enelsonmoore@gmail.com
cmdline_find_option() returns the full length of the parsed acpi_rsdp=
value. get_cmdline_acpi_rsdp() then silently truncates values which do
not fit in the val[] buffer.

Prevent boot_kstrtoul() from parsing a truncated value and then the
kernel from silently using the wrong RSDP address, see discussion in
Link:.

Issue a warning so that the user is aware that s/he supplied a malformed
value and can get feedback instead of silent crashes.

  [ bp: Make commit message more precise. ]

Fixes: 3c98e71 ("x86/boot: Add "acpi_rsdp=" early parsing")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20260617130417.36651-4-thorsten.blum@linux.dev
None of the code relating to mark_new_valid_map() does anything useful
without CONFIG_64BIT=y && CONFIG_MMU=y, because the
new_valid_map_cpus_check code is only used if CONFIG_64BIT, and the
exception codes checked there can only happen with CONFIG_MMU=y.

Therefore, make these conditional on CONFIG_64BIT=y && CONFIG_MMU=y to
simplify programming, since we do not have to handle CONFIG_MMU=n when
changing this code in the future. This also removes some unused code on
the entry path for CONFIG_MMU=n.

Signed-off-by: Vivian Wang <wangruikang@iscas.ac.cn>
Link: https://patch.msgid.link/20260713-mark-after-vmemmap-populate-v6-1-b945ceba29d4@iscas.ac.cn
Signed-off-by: Paul Walmsley <pjw@kernel.org>
section_activate() does not flush TLB after populating new vmemmap
pages. On most architectures, this is okay. However it is a problem on
RISC-V since there the TLB caching non-present entries is permitted,
which causes spurious faults on some hardwares.

This seems to be most easily reproduced with DEBUG_VM=y and
PAGE_POISONING=y, which causes these newly mapped struct pages to be
poisoned i.e. written to immediately after mapping.

Extend the RISC-V flush_cache_vmap() to also handle the vmemmap range,
and call it after hotplugging vmemmap, which gets the possible spurious
fault handled in the exception handler.

At least for now, the only other architecture with both
SPARSEMEM_VMEMMAP and flush_cache_vmap() is PowerPC, which has a similar
problem with newly valid PTEs. But there flush_cache_vmap() is just a
ptesync. So it should be safe to do this for generic code while having
minimal performance impact.

Suggested-by: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Vivian Wang <wangruikang@iscas.ac.cn>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Link: https://patch.msgid.link/20260713-mark-after-vmemmap-populate-v6-2-b945ceba29d4@iscas.ac.cn
Signed-off-by: Paul Walmsley <pjw@kernel.org>
The FUNCTION_ALIGNMENT_4B select forces the whole kernel to be built
with -fmin-function-alignment=4. This alignment is only needed so the
patchable-function-entry NOPs, which arch/riscv/Makefile emits under
CONFIG_DYNAMIC_FTRACE, can be patched reliably on RISCV_ISA_C=y builds
where compressed instructions otherwise allow 2-byte function
alignment.

The select is currently gated on HAVE_DYNAMIC_FTRACE, a capability bit
that is selected whenever the toolchain supports dynamic ftrace, rather
than on whether tracing is actually enabled. As a result every
RISCV_ISA_C=y build gets 4-byte function alignment across the entire
kernel even when function tracing is disabled, needlessly growing the
kernel image and wasting instruction cache for a feature that is not
in use.

Gate the select on DYNAMIC_FTRACE instead, matching the condition under
which arch/riscv/Makefile emits -fpatchable-function-entry, so the
alignment is only applied when it is actually needed.

Fixes: c41bf43 ("riscv: ftrace: align patchable functions to 4 Byte boundary")
Signed-off-by: Rui Qi <qirui.001@bytedance.com>
Link: https://patch.msgid.link/20260706130415.463682-1-qirui.001@bytedance.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
When port I/O is not supported, exposing the port-string helpers is both
unnecessary and can make clang diagnose null-pointer arithmetic from the
PCI_IOBASE based address expression.  Keep the MMIO string helpers
available as before, but only provide the port I/O variants when
CONFIG_HAS_IOPORT is enabled.

Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20260703122832.15984-2-cuiyunhui@bytedance.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
With LTO enabled the compiler assumes that the vDSO functions are not
used and optimizes them away completely. Currently this happens to
__vdso_clock_getres(), __vdso_clock_gettime(), __vdso_getrandom(),
__vdso_gettimeofday() and __vdso_riscv_hwprobe().

Disable LTO for the vDSO, as these functions are hand-optimized anyways.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202606301855.WvkSC4kD-lkp@intel.com/
Fixes: 021d234 ("RISC-V: build: Allow LTO to be selected")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://patch.msgid.link/20260701-riscv-vdso-lto-v1-1-89db0cd82077@linutronix.de
Signed-off-by: Paul Walmsley <pjw@kernel.org>
When the baud rate is empty, 0, invalid, or overflows to 0 when stored
as an int, the system will hang during early boot because of a division
by zero in early_serial_init().

Fall back to DEFAULT_BAUD when the resulting baud rate is 0 to prevent
an early system hang.

Fixes: ce0aa5d ("x86, setup: Make the setup code also accept console=uart8250")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260713194924.126472-3-thorsten.blum@linux.dev
dw_spi_dma_wait_tx_done() polls dw_spi_dma_tx_busy(), which only checks
DW_SPI_SR_TF_EMPT. An empty TX FIFO merely means the last data word has
been moved into the shift register; the transfer is not complete on the
bus until DW_SPI_SR_BUSY is also cleared. As a result the wait can
return while the controller is still shifting out the final word.

Any caller that tears down or reconfigures the controller right after
the transfer can then lose the tail of the transfer.

The memory-operation path in spi-dw-core.c already waits for both
DW_SPI_SR_BUSY == 0 and DW_SPI_SR_TF_EMPT == 1. Use the same completion
condition in the DMA path so the transfer is guaranteed to be finished
on the bus before the wait returns.

Signed-off-by: Wang YuWei <1973615295@qq.com>
Link: https://patch.msgid.link/tencent_4EA7B5C94669ED4C38A5F6C1C9126E5D9106@qq.com
Signed-off-by: Mark Brown <broonie@kernel.org>
…s enabled

When use_dma_read is enabled, the IRQ handler unconditionally overwrites
irq_status with the return value of get_dma_status(). For write operations,
DMA status returns 0 since no DMA read is in progress, causing irq_status
to become 0. The subsequent completion signal is never triggered and the
write operation times out with -ETIMEDOUT:

  cadence-qspi f1010000.spi: Indirect write timeout
  spi-nor spi0.1: operation failed with -110

Fix this by separating the DMA completion path from the write interrupt
path. If get_dma_status() indicates DMA read completion, signal completion
and return immediately. Otherwise, preserve the original irq_status so that
write completion interrupts are correctly recognized and signalled.

Fixes: aac733a ("spi: cadence-qspi: Fix style and improve readability")
Signed-off-by: Srikanth Boyapally <srikanth.boyapally@amd.com>
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Link: https://patch.msgid.link/20260708045148.2993313-1-srikanth.boyapally@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The provided-buffer validation fix deferred freeing a cached iovec
until validation completed. However, the deferred free uses arg->iovs.
After a grow, that points to the newly allocated array. Without a grow,
it points to the cached array that remains in use.

This leaves the caller with a dangling iovec in both cases and can
result in repeated frees. Only free org_iovs when arg->iovs actually
replaced it.

Fixes: cd053d7 ("io_uring: fix dangling iovec after provided-buffer bundle grow failure")
Assisted-by: Codex:gpt-5.3-codex-spark
Signed-off-by: Jaeyeong Lee <iostreampy@proton.me>
Link: https://patch.msgid.link/20260712142612.188695595-iostreampy@proton.me
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Zero check unused SQE fields addr3 and pad2 for unlinkat. They're
not needed now, but could be used sometime in the future.

Signed-off-by: Yi Xie <xieyi@kylinos.cn>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://patch.msgid.link/20260714030306.64820-1-xieyi@kylinos.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When CONFIG_RISCV_USER_CFI is enabled, the CFI version of the vDSO, has
a CFI landing pad instruction at the start of __vdso_rt_sigreturn. This
breaks libgcc's unwinding code which matches on the first two
instructions. Other unwinders that rely on similar instruction matching
may also be affected.

Since __vdso_rt_sigreturn is reached as part of signal-return handling
rather than via an indirect call/jump from userspace, it does not need a
CFI landing pad. Remove it and restore the instruction sequence expected
by existing unwinding code.

This matches what was done on arm64 in commit 9a96428 ("arm64:
vdso: Don't prefix sigreturn trampoline with a BTI C instruction") for a
similar issue.

Cc: stable@vger.kernel.org
Fixes: 37f57bd ("arch/riscv: compile vdso with landing pad and shadow stack note")
Co-authored-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://patch.msgid.link/20260623204058.498120-1-aurelien@aurel32.net
[pjw@kernel.org: fixed comment style]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
When cpusetsize < cpumask_size(), hwprobe_get_cpus() did not fully
initialize its copy of the cpu mask, which could cause non-deterministic
results from the riscv_hwprobe syscall on a system with more than 8 CPUs
when the supplied cpu mask is empty.  Address this by fully initializing
the cpu mask.

Fixes: e178bf1 ("RISC-V: hwprobe: Introduce which-cpus flag")
Signed-off-by: Mark Harris <mark.hsj@gmail.com>
Reviewed-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Michael Ellerman <mpe@kernel.org>
Link: https://patch.msgid.link/20260714003056.73707-1-mark.hsj@gmail.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
blk_time_get_ns() populates the per-plug cached timestamp and then
returns it by re-reading the field:

	if (!plug->cur_ktime) {
		plug->cur_ktime = ktime_get_ns();
		current->flags |= PF_BLOCK_TS;
	}
	return plug->cur_ktime;

This is problematic when the compiler emits the final
"return plug->cur_ktime" as a reload from memory, after PF_BLOCK_TS has
already been set.

Since the cached timestamp is now invalidated from finish_task_switch()
(fad156c "block: invalidate cached plug timestamp after task
switch"), a task preempted between setting PF_BLOCK_TS and that reload
has plug->cur_ktime zeroed by blk_plug_invalidate_ts() when it is
scheduled back in.  The reload then returns 0.

A 0 handed back here is stored as a start timestamp -- e.g.
blk_account_io_start() writes it to rq->start_time_ns -- and later
subtracted from "now".  blk_account_io_done() then adds (now - 0), i.e.
roughly the system uptime, to the per-group nsecs[] counters.  On an
otherwise idle, healthy device this appears as sudden ~uptime-sized jumps
in the diskstats time fields (write_ticks/discard_ticks/time_in_queue).

The solution is to be explicit in our reads and writes to this field
that is preemption volatile.  We also add a barrier() to ensure that any
setting of PF_BLOCK_TS is ordered to happen after the cur_ktime update.

This issue was discovered using AI-assisted kprobes looking for paths
that were leaking zeroed timestamps in a live system, based on the
observation that we were sometimes seeing uptime-sized jumps in kernel
exported counters. This was flagged by NodeDiskIOSaturation
prometheus alerts that started firing on all hosts post 7.1.3 kernel
upgrade, due to node-exporter now exporting a nonsensical
node_disk_io_time_weighted_seconds_total.

Fixes: fad156c ("block: invalidate cached plug timestamp after task switch")
Cc: stable@vger.kernel.org
Signed-off-by: Mike Waychison <mike@waychison.com>
Assisted-by: Claude:claude-opus-4.8
Link: https://patch.msgid.link/20260715192950.2488921-1-mike@waychison.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 267ec4d ("loop: fix partition scan race between udev and
loop_reread_partitions()") stopped disk_force_media_change() from
setting GD_NEED_PART_SCAN because loop devices with LO_FLAGS_PARTSCAN
rescan partitions explicitly. However, partitions can also be added
manually with BLKPG while LO_FLAGS_PARTSCAN is clear.

When such a loop device is detached, __loop_clr_fd() skips
bdev_disk_changed(). Without GD_NEED_PART_SCAN, reopening the unbound
device no longer performs the previous lazy cleanup, leaving dead
partition devices behind. A subsequent LOOP_CONFIGURE can then fail its
partition scan with -EBUSY, as seen in blktests loop/009 after loop/008.

Call bdev_disk_changed() unconditionally during __loop_clr_fd(). The
disk capacity is already zero and the release path holds open_mutex, so
this drops all partitions without rescanning the detached backing file.

The new blktests loop/013 case covers this sequence by adding a partition
with BLKPG without LO_FLAGS_PARTSCAN, detaching the loop device, and
checking that the partition is gone when the device is reopened.

Fixes: 267ec4d ("loop: fix partition scan race between udev and loop_reread_partitions()")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202607150754.b660f5b9-lkp@intel.com
Signed-off-by: Daan De Meyer <daan@amutable.com>
Link: https://patch.msgid.link/20260715-b4-loop-partition-cleanup-v1-1-b9f59910cd1e@amutable.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When radix_tree_insert() fails in blkg_create(), the error path has two
issues:

1. blkg->online is set to true unconditionally, even when the blkg was
   never fully inserted.  Move the assignment inside the success block.

2. The error path calls blkg_put() without first calling
   percpu_ref_kill().  Because the refcount is still in percpu mode,
   percpu_ref_put() only does this_cpu_sub() without checking for zero,
   so blkg_release() is never triggered.  This permanently leaks the
   blkg memory, its percpu iostat, policy data, the parent blkg
   reference, and the cgroup css reference — the latter preventing the
   cgroup from ever being destroyed.

Fix by replacing blkg_put() with percpu_ref_kill(), matching the pattern
used in blkg_destroy().

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Link: https://patch.msgid.link/20260715132407.1469777-1-cui.tao@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
aix_partition() reads the logical-volume descriptor array as a single
sector and then scans it:

	if (numlvs && (d = read_part_sector(state, vgda_sector + 1, &sect))) {
		struct lvd *p = (struct lvd *)d;
		...
		for (i = 0; foundlvs < numlvs && i < state->limit; i++) {
			lvip[i].pps_per_lv = be16_to_cpu(p[i].num_lps);

p points at a single 512-byte sector, which holds SECTOR_SIZE /
sizeof(struct lvd) = 16 entries, but the loop runs until foundlvs reaches
the on-disk numlvs or i reaches state->limit (DISK_MAX_PARTS, 256).
numlvs is an on-disk __be16 read straight from the volume group
descriptor and is not validated, so a crafted AIX image with numlvs
larger than 16 and lvd entries whose num_lps fields are zero (so foundlvs
never advances) drives the loop to read p[i] well past the end of the
read sector buffer.

Commit d97a86c ("partitions: aix.c: off by one bug") hardened the
matching write of lvip[lv_ix] in 2014 but left this read loop unbounded.

Bound the scan to the number of struct lvd entries that fit in the
sector that was actually read.

Fixes: 6ceea22 ("partitions: add aix lvm partition support files")
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Link: https://patch.msgid.link/20260714114806.3761553-1-michael.bommarito@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
adam900710 and others added 19 commits July 15, 2026 16:33
During one of my local btrfs fstests runs, folio_alloc() inside
folio_alloc_greedy() triggered an allocation failure report when trying
to allocate an order-4 folio.

The kernel is from the latest development branch, which is utilizing
the IOMAP_DIO_BOUNCE flag for direct writes when the inode requires
checksum.

Unfortunately I didn't save the full log, only the function and the
order.

When the IOMAP_DIO_BOUNCE flag is utilized, we will hit the following call
chain:

 bio_iov_iter_bounce_write()
 |- folio_alloc_greedy()
    |- folio_alloc(gfp | __GFP_NORETRY, get_order(*size));

However __GFP_NORETRY will still emit an allocation failure report
when it fails.

And folio_alloc_greedy() will retry with a smaller order anyway, there
is no point in emitting that allocation failure report.

Append the __GFP_NOWARN flag to folio_alloc() for the larger-order folio
attempts.

Fixes: 8dd5e7c ("block: add helpers to bounce buffer an iov_iter into bios")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Link: https://patch.msgid.link/d10571445ee505d95ba6eaad7558fc1f556d2921.1784020005.git.wqu@suse.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
bio_copy_kern() allocates pages that are normally freed by the bio
completion callback. If blk_rq_append_bio() rejects the bio, however,
blk_rq_map_kern() only drops the bio reference. Since bio_put() does not
free pages referenced by the bio vectors, those pages leak.

This can happen when the bio exceeds the queue segment constraints or
when a later mapping cannot be merged into a request built by earlier
calls. Track whether the buffer was copied and free those pages before
dropping the rejected bio.

Fixes: 3a5a392 ("block: allow blk_rq_map_kern to append to requests")
Assisted-by: Codex:gpt-5.6-sol
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260715073518.96042-1-liu.yun@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When elevator_change() is called concurrently for the same queue, the
elevator_change_done() function runs concurrently as well. This function
adds or deletes kobjects for the debugfs entry of the queue. Then the
concurrent calls cause memory corruption of the kobjects and result in a
process hang. The core part of the elevator switch is protected by queue
freeze and q->elevator_lock. However, since the commit 559dc11
("block: move elv_register[unregister]_queue out of elevator_lock"), the
elevator_change_done() is not serialized. Hence the memory corruption
and the hang.

The failures are observed when udev-worker writes to a sysfs
queue/scheduler attribute file while the blktests test case block/005
writes to the same attribute file. The failure also can be recreated by
running two processes that write to the same queue/scheduler file
concurrently. The failure is observed since another commit 370ac28
("block: avoid cpu_hotplug_lock depedency on freeze_lock"). This commit
changed the behavior of queue freeze and it unveiled the failure.

Fix the failure by changing elv_iosched_store() to acquire
update_nr_hwq_lock as the writer lock instead of the reader lock. This
serializes the whole elevator switch steps, including the
elevator_change_done() call.

Fixes: 559dc11 ("block: move elv_register[unregister]_queue out of elevator_lock")
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Link: https://patch.msgid.link/20260716092237.1305030-1-shinichiro.kawasaki@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Rules listed through the error_injection debugfs file omit the block
operation they match.  As a result, rules that differ only in operation
are indistinguishable even though op is mandatory when adding a rule.

Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260715073341.95129-1-liu.yun@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When the per-CPU bio cache is enabled but empty, bio_alloc_percpu_cache()
returns NULL and bio_alloc_bioset() falls straight through to the mempool
fallback:

    if (unlikely(!bio)) {
        if (!(saved_gfp & __GFP_DIRECT_RECLAIM))
            return NULL;
        ...
    }

For non-sleeping allocations (no __GFP_DIRECT_RECLAIM) this returns NULL
without ever attempting a slab allocation, even when there is plenty of
free memory.

Commit b520c4e ("block: split bio_alloc_bioset more clearly into a
fast and slowpath") introduced this. Before it, a percpu cache miss fell
through to mempool_alloc(), which attempted the underlying slab allocation
first and only failed when that slab allocation failed. The restructuring
dropped the slab attempt that non-sleeping callers of a cache-enabled
bioset (such as the default fs_bio_set used by bio_alloc()) relied on.

Try a slab allocation with optimistic GFP_ flags before falling back to
the mempool whenever the bio is still NULL, so both the cache-empty and
non-cache paths share the same slab attempt. This restores the previous
behavior for non-sleeping allocations.

Fixes: b520c4e ("block: split bio_alloc_bioset more clearly into a fast and slowpath")
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260709020145.4011533-1-joseph.qi@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When CONFIG_PERSISTENT_HUGE_ZERO_FOLIO is enabled, iomap_dio_zero() can
add a huge zero folio to a zeroing bio, which needs special treatment
in bio_free_folios by also checking is_huge_zero_folio() in addition to
is_zero_folio().

Fixes: 8dd5e7c ("block: add helpers to bounce buffer an iov_iter into bios")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Link: https://patch.msgid.link/20260716091306.316625-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
bio_iov_iter_align_down expects the "normal" biovec layout from vector 0,
while bio_iov_iter_bounce_read abuses vector 0 for a bounce buffer
allocation.  Pass an explicit bvec to bio_iov_iter_align_down to deal
with this case to avoid a double unpin.

Additionally we need to free the folio if no bio_vec could be added,
and adjust the size of the first bio_vec that contains the bounce buffer
when the I/O size is aligned down.

Fixes: e7b8b3c ("block: align down bounces bios")
Reported-by: 0wnerD1ed <l7z@0b1t.tech>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: 0wnerD1ed <l7z@0b1t.tech>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://patch.msgid.link/20260716091306.316625-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The LTC3676_IRQSTAT_* bit definitions do not match the IRQSTAT
(Interrupt Request Status) register layout documented in Table 15
of the LTC3676/LTC3676-1 datasheet:

  bit 0 - Pushbutton Status Active
  bit 1 - Hard Reset Occurred
  bit 2 - PGOOD Timeout Occurred
  bit 3 - Undervoltage Warning
  bit 4 - Undervoltage Standby (Fault) Occurred
  bit 5 - Overtemperature Warning
  bit 6 - Overtemperature Standby (Fault) Occurred
  bit 7 - Reserved

The driver instead defines these starting at bit 3, one bit higher
than the datasheet specifies, which causes ltc3676_regulator_isr()
to check the wrong status bits and misreport (or miss) PGOOD
timeout, undervoltage and thermal warning/fault conditions.

Fix the bit offsets to match the datasheet.

Fixes: 37b918a ("regulator: Add LTC3676 support")
Cc: stable@vger.kernel.org
Signed-off-by: Abhishek Ojha <Abhishek.ojha@savoirfairelinux.com>
Link: https://patch.msgid.link/20260715170408.295552-1-Abhishek.ojha@savoirfairelinux.com
Signed-off-by: Mark Brown <broonie@kernel.org>
rhashtable_walk_start_check() has two restart paths when resuming a walk.
When iter->walker.tbl is valid, it re-validates iter->p against the table
and sets iter->p = NULL if the object is gone.  When iter->walker.tbl is
NULL (table was freed during resize), it resets slot and skip but forgets
to clear iter->p.

rhashtable_walk_next() then dereferences the stale iter->p, reading
freed memory.  This is a use-after-free.

Any caller that does multi-fragment rhashtable walks across
walk_stop/walk_start boundaries is affected.  Concrete cases include
netlink_diag (__netlink_diag_dump in net/netlink/diag.c) and TIPC
(tipc_nl_sk_walk in net/tipc/socket.c).

Crash stack (netlink_diag):
  BUG: KASAN: slab-use-after-free in rhashtable_walk_next+0x365/0x3c0
  Read of size 8 at addr ffff88801a9d2438 (freed kmalloc-2k, offset 1080)
  Call Trace:
   rhashtable_walk_next+0x365/0x3c0 (lib/rhashtable.c:1016)
   __netlink_diag_dump+0x160/0x760 (net/netlink/diag.c:122)
   netlink_diag_dump+0xc2/0x240
   netlink_dump+0x5bc/0x1270
   netlink_recvmsg+0x7a3/0x980
   sock_recvmsg+0x1bc/0x200
   __sys_recvfrom+0x1d4/0x2c0

Fixes: 5d240a8 ("rhashtable: improve rhashtable_walk stability when stop/start used.")
Cc: <stable@vger.kernel.org>
Reported-by: AutonomousCodeSecurity@microsoft.com
Reported-by: Yuan Tan <yuantan098@gmail.com>
Closes: https://lore.kernel.org/linux-crypto/CAB8m9Wh559e+=n8z51gB8DrbEyCc2mc0MgGjrRR6_VXBmU=2AQ@mail.gmail.com
Signed-off-by: Cen Zhang (Microsoft) <blbllhy@gmail.com>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
io_install_bpf() only rejects a second registration on the ctx side
(ctx->bpf_ops) and sets the per-map back-pointer ops->priv
unconditionally. The struct_ops link path never advances a map past
BPF_STRUCT_OPS_STATE_READY, so the same io_uring_bpf_ops map can be
registered more than once, and bpf_io_reg() re-resolves the target ring
via fget(ops->ring_fd) on every call. A caller can therefore point the
same ring_fd at a different io_ring_ctx between two BPF_LINK_CREATE
calls.

The second registration passes the ctx->bpf_ops check (the new ctx has
none) and overwrites ops->priv, orphaning the first ctx. Teardown
(io_eject_bpf()/bpf_io_unreg()) only reaches a ctx through ops->priv, so
the orphaned ctx is never torn down: its ctx->loop_step keeps pointing
into the struct_ops trampoline, which is freed once the map is gone. A
later io_uring_enter() on the orphaned ring then calls the dangling
ctx->loop_step from io_run_loop() -- a use-after-free of freed
executable memory, reachable by a task with CAP_BPF + CAP_PERFMON.

Reject registration when ops->priv is already set, as hid_bpf_reg()
does for its struct_ops.

Cc: stable@vger.kernel.org
Fixes: 98f3763 ("io_uring/bpf-ops: implement bpf ops registration")
Signed-off-by: Woraphat Khiaodaeng <worapat.kd2@gmail.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/20260717154537.129736-1-worapat.kd2@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
…ux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:

 - Reject too long acpi_rsdp= boot parameter values (Thorsten Blum)

 - Validate console=uart8250 baud rate to fix early boot hang (Thorsten
   Blum)

 - Remove dead Makefile rule (Ethan Nelson-Moore)

* tag 'x86-urgent-2026-07-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Validate console=uart8250 baud rate to fix early boot hang
  x86/boot: Reject too long acpi_rsdp= values
  x86/cpu: Remove Makefile rule for removed UMC CPU support
…nux/kernel/git/broonie/regulator

Pull regulator fix from Mark Brown:
 "One straightforward driver fix for some incorrectly described
  bitfields in the ltc3676 driver"

* tag 'regulator-fix-v7.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: ltc3676: Fix incorrect IRQSTAT bit offsets
…rnel/git/broonie/spi

Pull spi fixes from Mark Brown:
 "A couple of fairly routine driver fixes, nothing too remarkable"

* tag 'spi-fix-v7.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: cadence-quadspi: Fix indirect write timeout when DMA read mode is enabled
  spi: dw-dma: Wait for controller idle before completing Tx
…ux/kernel/git/axboe/linux

Pull io_uring fixes from Jens Axboe:

 - Fix a use-after-free in the bpf-ops struct_ops path, where the same
   io_uring_bpf_ops map could be registered more than once.

 - Fix the deferred iovec free for the provided-buffer grow path, which
   could leave the caller with a dangling iovec and result in repeated
   frees. Follow-up to the earlier fix in this series.

 - Zero-check the unused addr3/pad2 SQE fields for unlinkat

* tag 'io_uring-7.2-20260717' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring/bpf-ops: reject re-registration of an already-bound ops
  io_uring/fs: check unused sqe fields for unlinkat
  io_uring/kbuf: free the replaced iovec after a successful grow
…kernel/git/axboe/linux

Pull block fixes from Jens Axboe:

 - Fixes for the dio bounce buffer helpers: correct the alignment of
   bounced dio read bios to avoid a double unpin, handle huge zero
   folios in bio_free_folios(), and don't warn on the larger-order folio
   attempts in the greedy allocation path.

 - Try a slab allocation in bio_alloc_bioset() before falling back to
   the mempool, restoring the previous behavior for non-sleeping
   allocations from a cache-enabled bioset.

 - Serialize elevator changes for the same queue using the writer lock.

 - Fix a race in blk_time_get_ns() where a task preempted between
   setting PF_BLOCK_TS and the cached-timestamp reload could return 0.

 - blk-cgroup fix for leaks and the online flag on a radix_tree_insert()
   failure in blkg_create().

 - Free the copied pages when blk_rq_map_kern() fails after
   blk_rq_append_bio() rejects the bio.

 - Remove manually added partitions on loop device detach, fixing dead
   partition devices left behind and a subsequent LOOP_CONFIGURE -EBUSY

 - Bound the AIX partition lvd scan to the sector that was actually
   read.

 - Show the block operation in error injection rules (Jackie)

* tag 'block-7.2-20260717' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  block: fix aligning of bounced dio read bios
  block: handle huge zero folios in bio_free_folios
  block: try slab allocation in bio_alloc_bioset() before mempool
  block: show operation in error injection rules
  block: serialize elevator changes for the same queue using a writer lock
  block: free copied pages when blk_rq_map_kern() fails
  block: do not warn when doing greedy allocation in folio_alloc_greedy()
  partitions: aix: bound the lvd scan to one sector
  blk-cgroup: fix leaks and online flag on radix_tree_insert failure
  loop: remove manually added partitions on detach
  block: fix race in blk_time_get_ns() returning 0
…inux/kernel/git/riscv/linux

Pull RISC-V fixes from Paul Walmsley:

 - Call flush_cache_vmap() after populating new vmemmap pages, on all
   architectures. This avoids spurious faults on RISC-V
   microarchitectures that cache PTEs marked as non-present

 - Disable LTO for the vDSO to prevent the compiler from eliding
   functions that are used, but which don't appear to be

 - Fix an issue with libgcc's unwinder and signal handlers by dropping
   an unnecessary CFI landing pad instruction in __vdso_rt_sigreturn
   (similar to what was done on ARM64)

 - Avoid reading uninitialized memory under certain conditions in
   hwprobe_get_cpus()

 - Save some memory and I$ when CONFIG_DYNAMIC_FTRACE=n by avoiding our
   four-byte function alignment requirement in that case

 - Avoid clang warnings about null-pointer arithmetic in the I/O-port
   accessor macros (inb, outb, etc.) by ifdeffing them out when
   !CONFIG_HAS_IOPORT

 - Make the build of the lazy TLB flushing code in the vmalloc path
   depend on CONFIG_64BIT and CONFIG_MMU (since those platforms are the
   only ones that use it)

* tag 'riscv-for-linus-7.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: hwprobe: Avoid uninitialized read in hwprobe_get_cpus()
  arch/riscv: vdso: remove CFI landing pad from rt_sigreturn
  riscv: vdso: Do not use LTO for the vDSO
  riscv: io: avoid null-pointer arithmetic in PIO helpers
  riscv: Gate FUNCTION_ALIGNMENT_4B on DYNAMIC_FTRACE
  mm/sparse-vmemmap: flush_cache_vmap() after hotplugging vmemmap
  riscv: mm: Make mark_new_valid_map() stuff depend on 64BIT && MMU
…herbert/crypto-2.6

Pull crypto fix from Herbert Xu:

 - Fix potential crash in rhashtable walk

* tag 'v7.2-p2' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  rhashtable: clear stale iter->p on table restart
…rg/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "12 hotfixes. 8 are cc:stable and the remainder address post-7.1 issues
  or aren't considered appropriate for backporting. 10 are for MM.

  All are singletons - please see the relevant changelogs for details"

* tag 'mm-hotfixes-stable-2026-07-20-11-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/memory-failure: trace: change memory_failure_event to ras subsystem
  mm: page_reporting: allow driver to set batch capacity
  mm/kmemleak: fix checksum computation for per-cpu objects
  mm/damon/core: disallow overlapping input ranges for damon_set_regions()
  MAINTAINERS: add Usama as a THP reviewer
  fat: avoid stack overflow warning
  mm/damon/core: validate ranges in damon_set_regions()
  m68k: avoid -Wunused-but-set-parameter in clear_user_page()
  mm/huge_memory: set PG_has_hwpoisoned only after new folio head is established
  mm/page_vma_mapped: fix device-private PMD handling
  MAINTAINERS: s/SeongJae/SJ/
  userfaultfd: prevent registration of special VMAs
@sunflower2333
sunflower2333 merged commit 00f4f1a into sunflower2333:master Jul 21, 2026
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