linux.git/include/linux, branch v6.15

Disable FOP_DONTCACHE for now due to bugs

2025-05-25T22:43:36+00:00

This is kind of last-minute, but Al Viro reported that the new
FOP_DONTCACHE flag causes memory corruption due to use-after-free
issues.

This was triggered by commit 974c5e6139db ("xfs: flag as supporting
FOP_DONTCACHE"), but that is not the underlying bug - it is just the
first user of the flag.

Vlastimil Babka suspects the underlying problem stems from the
folio_end_writeback() logic introduced in commit fb7d3bc414939
("mm/filemap: drop streaming/uncached pages when writeback completes").

The most straightforward fix would be to just revert the commit that
exposed this, but Matthew Wilcox points out that other filesystems are
also starting to enable the FOP_DONTCACHE logic, so this instead
disables that bit globally for now.

The fix will hopefully end up being trivial and we can just re-enable
this logic after more testing, but until such a time we'll have to
disable the new FOP_DONTCACHE flag.

Reported-by: Al Viro 
Link: https://lore.kernel.org/all/20250525083209.GS2023217@ZenIV/
Triggered-by: 974c5e6139db ("xfs: flag as supporting FOP_DONTCACHE")
Cc: Vlastimil Babka 
Cc: Matthew Wilcox 
Cc: Jan Kara 
Cc: Jens Axboe 
Cc: Christoph Hellwig 
Cc: Darrick J. Wong 
Cc: Christian Brauner 
Signed-off-by: Linus Torvalds

Merge tag 'mm-hotfixes-stable-2025-05-25-00-58' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-05-25T14:48:35+00:00

Pull hotfixes from Andrew Morton:
 "22 hotfixes.

  13 are cc:stable and the remainder address post-6.14 issues or aren't
  considered necessary for -stable kernels. 19 are for MM"

* tag 'mm-hotfixes-stable-2025-05-25-00-58' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (22 commits)
  mailmap: add Jarkko's employer email address
  mm: fix copy_vma() error handling for hugetlb mappings
  memcg: always call cond_resched() after fn()
  mm/hugetlb: fix kernel NULL pointer dereference when replacing free hugetlb folios
  mm: vmalloc: only zero-init on vrealloc shrink
  mm: vmalloc: actually use the in-place vrealloc region
  alloc_tag: allocate percpu counters for module tags dynamically
  module: release codetag section when module load fails
  mm/cma: make detection of highmem_start more robust
  MAINTAINERS: add mm memory policy section
  MAINTAINERS: add mm ksm section
  kasan: avoid sleepable page allocation from atomic context
  highmem: add folio_test_partial_kmap()
  MAINTAINERS: add hung-task detector section
  taskstats: fix struct taskstats breaks backward compatibility since version 15
  mm/truncate: fix out-of-bounds when doing a right-aligned split
  MAINTAINERS: add mm reclaim section
  MAINTAINERS: update page allocator section
  mm: fix VM_UFFD_MINOR == VM_SHADOW_STACK on USERFAULTFD=y && ARM64_GCS=y
  mm: mmap: map MAP_STACK to VM_NOHUGEPAGE only if THP is enabled
  ...

mm: fix copy_vma() error handling for hugetlb mappings

2025-05-25T07:53:49+00:00

If, during a mremap() operation for a hugetlb-backed memory mapping,
copy_vma() fails after the source vma has been duplicated and opened (ie. 
vma_link() fails), the error is handled by closing the new vma.  This
updates the hugetlbfs reservation counter of the reservation map which at
this point is referenced by both the source vma and the new copy.  As a
result, once the new vma has been freed and copy_vma() returns, the
reservation counter for the source vma will be incorrect.

This patch addresses this corner case by clearing the hugetlb private page
reservation reference for the new vma and decrementing the reference
before closing the vma, so that vma_close() won't update the reservation
counter.  This is also what copy_vma_and_data() does with the source vma
if copy_vma() succeeds, so a helper function has been added to do the
fixup in both functions.

The issue was reported by a private syzbot instance and can be reproduced
using the C reproducer in [1].  It's also a possible duplicate of public
syzbot report [2].  The WARNING report is:

============================================================
page_counter underflow: -1024 nr_pages=1024
WARNING: CPU: 0 PID: 3287 at mm/page_counter.c:61 page_counter_cancel+0xf6/0x120
Modules linked in:
CPU: 0 UID: 0 PID: 3287 Comm: repro__WARNING_ Not tainted 6.15.0-rc7+ #54 NONE
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-2-gc13ff2cd-prebuilt.qemu.org 04/01/2014
RIP: 0010:page_counter_cancel+0xf6/0x120
Code: ff 5b 41 5e 41 5f 5d c3 cc cc cc cc e8 f3 4f 8f ff c6 05 64 01 27 06 01 48 c7 c7 60 15 f8 85 48 89 de 4c 89 fa e8 2a a7 51 ff <0f> 0b e9 66 ff ff ff 44 89 f9 80 e1 07 38 c1 7c 9d 4c 81
RSP: 0018:ffffc900025df6a0 EFLAGS: 00010246
RAX: 2edfc409ebb44e00 RBX: fffffffffffffc00 RCX: ffff8880155f0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff81c4a23c R09: 1ffff1100330482a
R10: dffffc0000000000 R11: ffffed100330482b R12: 0000000000000000
R13: ffff888058a882c0 R14: ffff888058a882c0 R15: 0000000000000400
FS:  0000000000000000(0000) GS:ffff88808fc53000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004b33e0 CR3: 00000000076d6000 CR4: 00000000000006f0
Call Trace:
 
 page_counter_uncharge+0x33/0x80
 hugetlb_cgroup_uncharge_counter+0xcb/0x120
 hugetlb_vm_op_close+0x579/0x960
 ? __pfx_hugetlb_vm_op_close+0x10/0x10
 remove_vma+0x88/0x130
 exit_mmap+0x71e/0xe00
 ? __pfx_exit_mmap+0x10/0x10
 ? __mutex_unlock_slowpath+0x22e/0x7f0
 ? __pfx_exit_aio+0x10/0x10
 ? __up_read+0x256/0x690
 ? uprobe_clear_state+0x274/0x290
 ? mm_update_next_owner+0xa9/0x810
 __mmput+0xc9/0x370
 exit_mm+0x203/0x2f0
 ? __pfx_exit_mm+0x10/0x10
 ? taskstats_exit+0x32b/0xa60
 do_exit+0x921/0x2740
 ? do_raw_spin_lock+0x155/0x3b0
 ? __pfx_do_exit+0x10/0x10
 ? __pfx_do_raw_spin_lock+0x10/0x10
 ? _raw_spin_lock_irq+0xc5/0x100
 do_group_exit+0x20c/0x2c0
 get_signal+0x168c/0x1720
 ? __pfx_get_signal+0x10/0x10
 ? schedule+0x165/0x360
 arch_do_signal_or_restart+0x8e/0x7d0
 ? __pfx_arch_do_signal_or_restart+0x10/0x10
 ? __pfx___se_sys_futex+0x10/0x10
 syscall_exit_to_user_mode+0xb8/0x2c0
 do_syscall_64+0x75/0x120
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x422dcd
Code: Unable to access opcode bytes at 0x422da3.
RSP: 002b:00007ff266cdb208 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007ff266cdbcdc RCX: 0000000000422dcd
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00000000004c7bec
RBP: 00007ff266cdb220 R08: 203a6362696c6720 R09: 203a6362696c6720
R10: 0000200000c00000 R11: 0000000000000246 R12: ffffffffffffffd0
R13: 0000000000000002 R14: 00007ffe1cb5f520 R15: 00007ff266cbb000
 
============================================================

Link: https://lkml.kernel.org/r/20250523-warning_in_page_counter_cancel-v2-1-b6df1a8cfefd@igalia.com
Link: https://people.igalia.com/rcn/kernel_logs/20250422__WARNING_in_page_counter_cancel__repro.c [1]
Link: https://lore.kernel.org/all/67000a50.050a0220.49194.048d.GAE@google.com/ [2]
Signed-off-by: Ricardo Cañuelo Navarro 
Suggested-by: Lorenzo Stoakes 
Reviewed-by: Liam R. Howlett 
Cc: Florent Revest 
Cc: Jann Horn 
Cc: Oscar Salvador 
Cc: Vlastimil Babka 
Cc: 
Signed-off-by: Andrew Morton

alloc_tag: allocate percpu counters for module tags dynamically

2025-05-25T07:53:48+00:00

When a module gets unloaded it checks whether any of its tags are still in
use and if so, we keep the memory containing module's allocation tags
alive until all tags are unused.  However percpu counters referenced by
the tags are freed by free_module().  This will lead to UAF if the memory
allocated by a module is accessed after module was unloaded.

To fix this we allocate percpu counters for module allocation tags
dynamically and we keep it alive for tags which are still in use after
module unloading.  This also removes the requirement of a larger
PERCPU_MODULE_RESERVE when memory allocation profiling is enabled because
percpu memory for counters does not need to be reserved anymore.

Link: https://lkml.kernel.org/r/20250517000739.5930-1-surenb@google.com
Fixes: 0db6f8d7820a ("alloc_tag: load module tags into separate contiguous memory")
Signed-off-by: Suren Baghdasaryan 
Reported-by: David Wang <00107082@163.com>
Closes: https://lore.kernel.org/all/20250516131246.6244-1-00107082@163.com/
Tested-by: David Wang <00107082@163.com>
Cc: Christoph Lameter (Ampere) 
Cc: Dennis Zhou 
Cc: Kent Overstreet 
Cc: Pasha Tatashin 
Cc: Tejun Heo 
Cc: 
Signed-off-by: Andrew Morton

Merge tag 'spi-fix-v6.15-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

2025-05-25T01:48:17+00:00

Pull spi fixes from Mark Brown:
 "A few final fixes for v6.15, some driver fixes for the Freescale DSPI
  driver pulled over from their vendor code and another instance of the
  fixes Greg has been sending throughout the kernel for constification
  of the bus_type in driver core match() functions"

* tag 'spi-fix-v6.15-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: spi-fsl-dspi: Reset SR flags before sending a new message
  spi: spi-fsl-dspi: Halt the module after a new message transfer
  spi: spi-fsl-dspi: restrict register range for regmap access
  spi: use container_of_cont() for to_spi_device()

Merge tag 'net-6.15-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2025-05-22T16:15:19+00:00

Pull networking fixes from Paolo Abeni:
 "This is somewhat larger than what I hoped for, with a few PRs from
  subsystems and follow-ups for the recent netdev locking changes,
  anyhow there are no known pending regressions.

  Including fixes from bluetooth, ipsec and CAN.

  Current release - regressions:

   - eth: team: grab team lock during team_change_rx_flags

   - eth: bnxt_en: fix netdev locking in ULP IRQ functions

  Current release - new code bugs:

   - xfrm: ipcomp: fix truesize computation on receive

   - eth: airoha: fix page recycling in airoha_qdma_rx_process()

  Previous releases - regressions:

   - sched: hfsc: fix qlen accounting bug when using peek in
     hfsc_enqueue()

   - mr: consolidate the ipmr_can_free_table() checks.

   - bridge: netfilter: fix forwarding of fragmented packets

   - xsk: bring back busy polling support in XDP_COPY

   - can:
       - add missing rcu read protection for procfs content
       - kvaser_pciefd: force IRQ edge in case of nested IRQ

  Previous releases - always broken:

   - xfrm: espintcp: remove encap socket caching to avoid reference leak

   - bluetooth: use skb_pull to avoid unsafe access in QCA dump handling

   - eth: idpf:
       - fix null-ptr-deref in idpf_features_check
       - fix idpf_vport_splitq_napi_poll()

   - eth: hibmcge: fix wrong ndo.open() after reset fail issue"

* tag 'net-6.15-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (40 commits)
  octeontx2-af: Fix APR entry mapping based on APR_LMT_CFG
  octeontx2-af: Set LMT_ENA bit for APR table entries
  net/tipc: fix slab-use-after-free Read in tipc_aead_encrypt_done
  octeontx2-pf: Avoid adding dcbnl_ops for LBK and SDP vf
  selftests/tc-testing: Add an HFSC qlen accounting test
  sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue()
  idpf: fix idpf_vport_splitq_napi_poll()
  net: hibmcge: fix wrong ndo.open() after reset fail issue.
  net: hibmcge: fix incorrect statistics update issue
  xsk: Bring back busy polling support in XDP_COPY
  can: slcan: allow reception of short error messages
  net: lan743x: Restore SGMII CTRL register on resume
  bnxt_en: Fix netdev locking in ULP IRQ functions
  MAINTAINERS: Drop myself to reviewer for ravb driver
  net: dwmac-sun8i: Use parsed internal PHY address instead of 1
  net: ethernet: ti: am65-cpsw: Lower random mac address error print to info
  can: kvaser_pciefd: Continue parsing DMA buf after dropped RX
  can: kvaser_pciefd: Fix echo_skb race
  can: kvaser_pciefd: Force IRQ edge in case of nested IRQ
  idpf: fix null-ptr-deref in idpf_features_check
  ...

spi: use container_of_cont() for to_spi_device()

2025-05-22T11:03:28+00:00

Some places in the spi core pass in a const pointer to a device and the
default container_of() casts that away, which is not a good idea.
Preserve the proper const attribute by using container_of_const() for
to_spi_device() instead, which is what it was designed for.

Note, this removes the NULL check for a device pointer in the call, but
no one was ever checking for that return value, and a device pointer
should never be NULL overall anyway, so this should be a safe change.

Cc: Mark Brown 
Fixes: d69d80484598 ("driver core: have match() callback in struct bus_type take a const *")
Signed-off-by: Greg Kroah-Hartman 
Link: https://patch.msgid.link/2025052230-fidgeting-stooge-66f5@gregkh
Signed-off-by: Mark Brown

highmem: add folio_test_partial_kmap()

2025-05-21T05:49:39+00:00

In commit c749d9b7ebbc ("iov_iter: fix copy_page_from_iter_atomic() if
KMAP_LOCAL_FORCE_MAP"), Hugh correctly noted that if KMAP_LOCAL_FORCE_MAP
is enabled, we must limit ourselves to PAGE_SIZE bytes per call to
kmap_local().  The same problem exists in memcpy_from_folio(),
memcpy_to_folio(), folio_zero_tail(), folio_fill_tail() and
memcpy_from_file_folio(), so add folio_test_partial_kmap() to do this more
succinctly.

Link: https://lkml.kernel.org/r/20250514170607.3000994-2-willy@infradead.org
Fixes: 00cdf76012ab ("mm: add memcpy_from_file_folio()")
Signed-off-by: Matthew Wilcox (Oracle) 
Cc: Al Viro 
Cc: Hugh Dickins 
Cc: 
Signed-off-by: Andrew Morton

mm: fix VM_UFFD_MINOR == VM_SHADOW_STACK on USERFAULTFD=y && ARM64_GCS=y

2025-05-21T05:49:38+00:00

On configs with CONFIG_ARM64_GCS=y, VM_SHADOW_STACK is bit 38.  On configs
with CONFIG_HAVE_ARCH_USERFAULTFD_MINOR=y (selected by CONFIG_ARM64 when
CONFIG_USERFAULTFD=y), VM_UFFD_MINOR is _also_ bit 38.

This bit being shared by two different VMA flags could lead to all sorts
of unintended behaviors.  Presumably, a process could maybe call into
userfaultfd in a way that disables the shadow stack vma flag.  I can't
think of any attack where this would help (presumably, if an attacker
tries to disable shadow stacks, they are trying to hijack control flow so
can't arbitrarily call into userfaultfd yet anyway) but this still feels
somewhat scary.

Link: https://lkml.kernel.org/r/20250507131000.1204175-2-revest@chromium.org
Fixes: ae80e1629aea ("mm: Define VM_SHADOW_STACK for arm64 when we support GCS")
Signed-off-by: Florent Revest 
Reviewed-by: Mark Brown 
Cc: Borislav Betkov 
Cc: Brendan Jackman 
Cc: Catalin Marinas 
Cc: Florent Revest 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Thiago Jung Bauermann 
Cc: Thomas Gleinxer 
Cc: Will Deacon 
Cc: 
Signed-off-by: Andrew Morton

mm: mmap: map MAP_STACK to VM_NOHUGEPAGE only if THP is enabled

2025-05-21T05:49:38+00:00

commit c4608d1bf7c6 ("mm: mmap: map MAP_STACK to VM_NOHUGEPAGE") maps the
mmap option MAP_STACK to VM_NOHUGEPAGE.  This is also done if
CONFIG_TRANSPARENT_HUGEPAGE is not defined.  But in that case, the
VM_NOHUGEPAGE does not make sense.

I discovered this issue when trying to use the tool CRIU to checkpoint and
restore a container.  Our running kernel is compiled without
CONFIG_TRANSPARENT_HUGEPAGE.  CRIU parses the output of /proc//smaps
and saves the "nh" flag.  When trying to restore the container, CRIU fails
to restore the "nh" mappings, since madvise() MADV_NOHUGEPAGE always
returns an error because CONFIG_TRANSPARENT_HUGEPAGE is not defined.

Link: https://lkml.kernel.org/r/20250507-map-map_stack-to-vm_nohugepage-only-if-thp-is-enabled-v5-1-c6c38cfefd6e@kuka.com
Fixes: c4608d1bf7c6 ("mm: mmap: map MAP_STACK to VM_NOHUGEPAGE")
Signed-off-by: Ignacio Moreno Gonzalez 
Acked-by: David Hildenbrand 
Reviewed-by: Lorenzo Stoakes 
Reviewed-by: Yang Shi 
Reviewed-by: Liam R. Howlett 
Cc: 
Signed-off-by: Andrew Morton