linux-stable.git/arch, branch v6.6.145

KVM: Move kvm_io_bus_get_dev() locking responsibilities to callers

2026-07-24T14:03:52+00:00

commit 3a07249981629ace483ebbef81ef6b34c2d2afec upstream.

kvm_io_bus_get_dev() returns a device that is only matched by the
address, and nothing else. This can cause a lifetime issue if
the matched device is not the expected type, as by the time
the caller can introspect the object, it might be gone (the srcu
lock having been dropped).

Given that there is only a single user of this helper, the simplest
option is to move the locking responsibility to the caller, which
can keep the srcu lock held for as long as it wants.

Note that this aligns with other kvm_io_bus*() helpers, which
already require the srcu lock to be held by the callers.

Reported-by: Will Deacon 
Fixes: 8a39d00670f07 ("KVM: kvm_io_bus: Add kvm_io_bus_get_dev() call")
Link: https://lore.kernel.org/all/20260626111344.802555-1-maz@kernel.org
Cc: stable@vger.kernel.org
Reviewed-by: Oliver Upton 
Link: https://patch.msgid.link/20260627105105.1005990-1-maz@kernel.org
Signed-off-by: Marc Zyngier 
Signed-off-by: Greg Kroah-Hartman

perf/x86/intel/uncore: Defer ADL global PMON enable to enable_box()

2026-07-24T14:03:49+00:00

[ Upstream commit 9a0bb848a37150aeccc10088e141339917d995dc ]

On some Raptor Cove CPUs, enabling uncore PMON globally at driver init
may increase power consumption even when no perf events are in use.

Drop adl_uncore_msr_init_box() and defer programming the global control
register to enable_box(), so it is only set when a box is actually used.

IMC and IMC freerunning counters use a separate control path and are
unaffected.

Fixes: 772ed05f3c5c ("perf/x86/intel/uncore: Add Alder Lake support")
Signed-off-by: Zide Chen 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Dapeng Mi 
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260602144908.263680-5-zide.chen@intel.com
[ deleted adl_uncore_msr_init_box() in its 6.12 wrmsrl() spelling since the tree predates the wrmsrq() rename ]
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

perf/x86/amd/brs: Fix kernel address leakage

2026-07-24T14:03:46+00:00

commit 47915e855fb38b42133e31ba917d99565f862154 upstream.

A user-only branch stack can contain branches that originate from
the kernel. As a result, kernel addresses are exposed to user space
even when PERF_SAMPLE_BRANCH_USER is requested. On AMD processors
supporting X86_FEATURE_BRS (Zen 3 only), perf can still report entries
such as SYSRET/interrupt returns for which the branch-from addresses
are in the kernel.

E.g.

  $ perf record -j any,u -c 4000 -e branch-brs -o - -- \
        perf bench syscall basic --loop 1000 | \
        perf script -i - -F brstack|tr ' ' '\n'| \
        grep -E '0x[89a-f][0-9a-f]{15}'

  ...
  0xffffffff810001c4/0x72e2e32955eb/-/-/-/0//-
  0xffffffff810001c4/0x72e2d94a9821/-/-/-/0//-
  0xffffffff810001c4/0x72e2d94ffa1b/-/-/-/0//-
  ...

BRS provides no hardware branch filtering, so privilege level
filtering is performed entirely in software. However, amd_brs_match_plm()
only validates the branch-to address against the requested privilege
levels. For branches from the kernel to user space, the branch-from
address is left unchecked and is leaked. Extend the software filter to
also validate the branch-from address, so that any branch record whose
branch-from address is in the kernel is dropped when
PERF_SAMPLE_BRANCH_USER is requested.

Fixes: 8910075d61a3 ("perf/x86/amd: Enable branch sampling priv level filtering")
Reported-by: Sashiko 
Signed-off-by: Sandipan Das 
Signed-off-by: Ingo Molnar 
Cc: stable@vger.kernel.org
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: https://patch.msgid.link/f05931c4f89a146c364bd5dc6b8170b1ac611c65.1783701239.git.sandipan.das@amd.com
Closes: https://lore.kernel.org/all/20260710110235.F3FD81F000E9@smtp.kernel.org/
[sandipan: backport to linux-6.6.y]
Signed-off-by: Sandipan Das 
Signed-off-by: Greg Kroah-Hartman

powerpc/spufs: fix out-of-bounds access in spufs_mem_mmap_access()

2026-07-24T14:03:45+00:00

commit 47b87f469a35b5ffc81c16eee6b13a9b6c8d55c6 upstream.

spufs_mem_mmap_access() computes the local store offset as
address - vma->vm_start, but bounds-checks it against vma->vm_end
instead of the local store size. On 64-bit, offset is always well
below vma->vm_end, so the clamp never fires and len stays unbounded
against the LS_SIZE buffer returned by ctx->ops->get_ls().

Reject offsets at or beyond LS_SIZE and clamp len to the remaining
space, mirroring the guard already used by spufs_mem_mmap_fault() and
spufs_ps_fault().

Fixes: a352894d0705 ("spufs: use new vm_ops->access to allow local state access from gdb")
Reported-by: Yuhao Jiang 
Cc: stable@vger.kernel.org
Signed-off-by: Junrui Luo 
Signed-off-by: Madhavan Srinivasan 
Link: https://patch.msgid.link/SYBPR01MB7881EE775E8B51C09F5A29E7AF152@SYBPR01MB7881.ausprd01.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: fix memory leak on krealloc failure in papr_init

2026-07-24T14:03:45+00:00

commit bd83c98b988d2c560531084e296dbfb530aff829 upstream.

When krealloc() fails, free the original esi_buf before returning to
avoid a memory leak.

Fixes: 3c14b73454cf ("powerpc/pseries: Interface to represent PAPR firmware attributes")
Cc: stable@vger.kernel.org
Signed-off-by: Thorsten Blum 
Signed-off-by: Madhavan Srinivasan 
Link: https://patch.msgid.link/20260614142356.658212-2-thorsten.blum@linux.dev
Signed-off-by: Greg Kroah-Hartman

riscv: Prevent NULL pointer dereference in machine_kexec_prepare()

2026-07-24T14:03:44+00:00

commit 81bbcff0c053c4f5c711c31a9b72fc492bd96c3f upstream.

A NULL pointer dereference issue is noticed in riscv's
machine_kexec_prepare(), where image->segment[i].buf might be NULL and
copied unchecked.

The NULL buf comes from ima_add_kexec_buffer(), where kbuf is added by
kexec_add_buffer(), but kbuf.buffer is NULL, then it is copied without
a check in machine_kexec_prepare():

  kexec_file_load
    -> kimage_file_alloc_init()
       -> kimage_file_prepare_segments()
          -> ima_add_kexec_buffer()
             -> kexec_add_buffer()
    -> machine_kexec_prepare()
       -> memcpy()

Address this by adding a check before the data copy attempt.

Fixes: b7fb4d78a6ad ("RISC-V: use memcpy for kexec_file mode")
Cc: stable@vger.kernel.org
Closes: https://lore.kernel.org/kexec/CAO7dBbVftLUhd2qrh7hmijTB3PEPfZAhykCGqEfrPoOcSrrj-w@mail.gmail.com/
Acked-by: Baoquan He 
Acked-by: Pratyush Yadav 
Reviewed-by: Nutty Liu 
Signed-off-by: Tao Liu 
Link: https://patch.msgid.link/20260705232706.30265-2-ltao@redhat.com
Signed-off-by: Paul Walmsley 
Signed-off-by: Greg Kroah-Hartman

riscv: probes: save original sp in rethook trampoline

2026-07-24T14:03:44+00:00

commit bc7b086a45521a986a49045907f017e3e46c763e upstream.

Reading a word from the stack in a kretprobe crashes a risc-v kernel.

$ cd /sys/kernel/tracing/
$ echo 'r n_tty_write $stack0' > dynamic_events
$ echo 1 > events/kprobes/enable
Unable to handle kernel paging request at virtual address 0000000200000128
...
[] regs_get_kernel_stack_nth+0x26/0x38
[] process_fetch_insn+0x3ee/0x760
[] kretprobe_trace_func+0x116/0x1f0
[] kretprobe_dispatcher+0x4a/0x58
[] kretprobe_rethook_handler+0x5e/0x90
[] rethook_trampoline_handler+0x70/0x108
[] arch_rethook_trampoline_callback+0x12/0x1c
[] arch_rethook_trampoline+0x48/0x94
[] tty_write+0x1a/0x30

In regs_get_kernel_stack_nth, regs->sp contains an arbitrary value.

arch_rethook_trampoline saves the registers from the probed function in a
struct pt_regs. sp is not saved. Instead, sp is decremented for
arch_rethook_trampoline's local stack.

Fix this crash and save the original sp along with the other registers.
Use a0 as a temporary register, it is overwritten anyway.

Cc: stable@vger.kernel.org
Fixes: c22b0bcb1dd02 ("riscv: Add kprobes supported")
Signed-off-by: Martin Kaiser 
Acked-by: Masami Hiramatsu (Google) 
Link: https://patch.msgid.link/20260630194010.1824039-1-martin@kaiser.cx
[pjw@kernel.org: added Fixes tag; cc'ed stable]
Signed-off-by: Paul Walmsley 
Signed-off-by: Greg Kroah-Hartman

LoongArch: Fix missing dirty page tracking in {pte,pmd}_wrprotect()

2026-07-24T14:03:43+00:00

commit 018e9828eb523c638fa3d9bdf0fd4956b74555b2 upstream.

When hardware page table walker (PTW) is enabled on LoongArch, the CPU
may set _PAGE_DIRTY directly in the page table entry during a write TLB
miss, without going through the software TLB store handler. The software
TLB store handler (tlbex.S:254) sets both _PAGE_DIRTY and_PAGE_MODIFIED
together:

    ori t0, t0, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED)

Since hardware PTW only sets _PAGE_DIRTY, the software-only bit, i.e.
_PAGE_MODIFIED is left unchanged. This creates a window where a PTE has
_PAGE_DIRTY set (hardware knows the page is dirty) but _PAGE_MODIFIED
clear (software is unaware).

When fork()/clone() triggers copy-on-write, __copy_present_ptes() calls
pte_wrprotect(), which unconditionally clears both the _PAGE_WRITE and
_PAGE_DIRTY bits:

    pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_DIRTY);

Since _PAGE_MODIFIED was never set, the dirtiness information is lost
completely. Subsequently, when memory pressure triggers page reclaim,
page_mkclean() / try_to_unmap() sees the page as clean (i.e. pte_dirty()
returns false) and the page may be freed without writeback, causing data
corruption.

Fix this by propagating the _PAGE_DIRTY bit to the _PAGE_MODIFIED bit in
both pte_wrprotect() and pmd_wrprotect() before clearing writeable bits:

    if (pte_val(pte) & _PAGE_DIRTY)
        pte_val(pte) |= _PAGE_MODIFIED;

The pmd_wrprotect() fix handles the CONFIG_TRANSPARENT_HUGEPAGE case,
where pmd entries need the same treatment.

This ensures the software dirty tracking bit (checked by pte_dirty() and
pmd_dirty(), which read both the _PAGE_DIRTY and _PAGE_MODIFIED bits) is
preserved across fork COW write-protection.

The issue was found by the LTP madvise09 test case, which exercises page
reclaim after "madvise(MADV_FREE), write and fork" operation sequence on
private anonymous mappings.

Cc: stable@vger.kernel.org
Fixes: 09cfefb7fa70 ("LoongArch: Add memory management")
Co-developed-by: Tianyang Zhang 
Signed-off-by: Tianyang Zhang 
Signed-off-by: Hongchen Zhang 
Signed-off-by: Huacai Chen 
Signed-off-by: Greg Kroah-Hartman

riscv: cacheinfo: Fix node reference leak in populate_cache_leaves

2026-07-24T14:03:36+00:00

commit bf4a195f063b0a0805c1417f6aad1dd32ea48f0f upstream.

Currently, the while loop drops the reference to prev in each iteration.
If the loop terminates early due to a break, the final of_node_put(np)
correctly drops the reference to the current node.

However, if the loop terminates naturally because np == NULL, calling
of_node_put(np) is a no-op. This leaves the last valid node stored in
prev without its reference dropped, resulting in a node reference leak.

Fix this by changing the final `of_node_put(np)` to `of_node_put(prev)`.

Fixes: 94f9bf118f1e ("RISC-V: Fix of_node_* refcount")
Cc: stable@vger.kernel.org
Assisted-by: Gemini:gemini-3.1-pro
Signed-off-by: Zishun Yi 
Link: https://patch.msgid.link/20260509074040.1747800-1-vulab@iscas.ac.cn
Signed-off-by: Paul Walmsley 
Signed-off-by: Greg Kroah-Hartman

mips: sched: Fix CPUMASK_OFFSTACK memory corruption

2026-07-24T14:03:36+00:00

commit 98e37db4a34d3af3fb2f4648295c25b5e40b20e3 upstream.

This patch addresses a critical memory management flaw. When
CONFIG_CPUMASK_OFFSTACK is enabled, cpumask_var_t is a pointer.
Consequently, sizeof(new_mask) evaluates to the pointer size, causing
copy_from_user() to clobber the mask pointer. Furthermore, the old
logic performed copy_from_user() before allocating the mask.

Fix this by allocating new_mask first. To handle variable-sized user
masks correctly, use cpumask_size() to truncate overly large user masks
or pad undersized masks with zeros before copying the data directly into
the allocated buffer.

Fixes: 295cbf6d63165 ("[MIPS] Move FPU affinity code into separate file.")
Cc: stable@vger.kernel.org
Signed-off-by: Aaron Tomlin 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Greg Kroah-Hartman