In the Linux kernel, the following vulnerability has been resolved:
ARM: 9475/1: entry: use byte load for KASAN VMAP stack shadow
Commit 44e9a3bb76e5 ("ARM: 9430/1: entry: Do a dummy read from
VMAP shadow") added a dummy read from the KASAN VMAP stack shadow in
__switch_to(). The read uses ldr, but the KASAN shadow address is
byte-granular and is not guaranteed to be word aligned.
ARMv5 faults unaligned word loads. With CONFIG_KASAN_VMALLOC and
CONFIG_VMAP_STACK enabled, ARM926/VersatilePB crashes in __switch_to()
with an alignment exception before reaching init.
Use ldrb for the dummy shadow access. The code only needs to fault in the
shadow mapping if the stack shadow is missing, so a byte load is sufficient
and matches the granularity of KASAN shadow memory.
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: mcp23s08: Initialize mcp->dev and mcp->addr before regmap init
Regmap initialization triggers regcache_maple_populate() which attempts
SPI read to populate cache. SPI read requires mcp->dev and mcp->addr to
be set, without them, NULL pointer dereference occurs during probe.
Move initialization before mcp23s08_spi_regmap_init() call.
In the Linux kernel, the following vulnerability has been resolved:
KVM: Don't WARN if memory is dirtied without a vCPU when the VM is dying
When marking a page dirty, complain about not having a running/loaded vCPU
if and only if the VM is still alive, i.e. its refcount is non-zero. This
will allow fixing a memory leak for x86 SEV-ES guests without hitting what
is effectively a false positive on the WARN.
For some SEV-ES VM-Exits, KVM keeps a writable mapping of a guest page
across an exit to userspace, and typically unmaps the page on the next
KVM_RUN. But if userspace never calls KVM_RUN after such an exit, then KVM
needs to unmap the page when the vCPU is destroyed, which in turn triggers
the WARN about not having a running vCPU.
Alternatively, SEV-ES could temporarily load the vCPU to suppress the WARN,
as is done in nested_vmx_free_vcpu() (but for completely unrelated reasons;
suppressing WARN from nested_put_vmcs12_pages() is pure happenstance). But
loading a vCPU during destruction is gross (ideally nVMX code would be
cleaned up), risks complicating the SEV-ES code (KVM would need to ensure
the temporarily load()+put() only runs when the vCPU isn't already loaded),
and is ultimately pointless.
The motivation for the WARN is to guard against KVM dirtying guest memory
without pushing the corresponding GFN to the active vCPU's dirty ring, e.g.
to ensure userspace doesn't miss a dirty page. But for the VM's refcount
to reach zero, there can't be _any_ userspace mappings to the dirty ring,
as mapping the dirty ring requires doing mmap() on the vCPU FD. I.e. if
userspace had a valid mapping for the dirty ring, then the vCPU file and
thus the owning VM would still be alive. And so since userspace can't
possibly reach the dirty ring, whether or not KVM technically "misses" a
push to the dirty ring is irrelevant.
In the Linux kernel, the following vulnerability has been resolved:
rust: arm64: set uwtable llvm module flag for CONFIG_UNWIND_TABLES
Due to a rustc bug [1] the -Cforce-unwind-tables=y flag only emits the
uwtable annotation for functions, but not for the module. This means
that compiler-generated functions such as 'asan.module_ctor' do not
receive the uwtable annotation.
When CONFIG_UNWIND_PATCH_PAC_INTO_SCS is enabled, this leads to boot
failures because the dwarf information emitted for the kasan
constructors is wrong, which causes the SCS boot patching code to
patch the constructor in an illegal manner. Specifically, the paciasp
instruction is patched, but the autiasp instruction is not. This
mismatch leads to a crash when the constructor is called during boot.
==================================================================
BUG: KASAN: global-out-of-bounds in do_basic_setup+0x4c/0x90
Read of size 8 at addr ffffffe3cc7eb488 by task swapper/0/1
Specifically the faulting instruction is the (*fn)() to invoke the
constructor in do_ctors() of the init/main.c file.
Once the fix lands in rustc, this flag can be made conditional on the
rustc version. Note that passing the flag on a rustc with the fix
present has no effect.
[ The fix [1] has landed for Rust 1.98.0 (expected release on
2026-08-20).
Thus add a version check as discussed.
- Miguel ]
[ Adjusted link and comment. - Miguel ]
In the Linux kernel, the following vulnerability has been resolved:
drm/virtio: Fix driver removal with disabled KMS
DRM atomic and modesetting aren't initialized if virtio-gpu driver built
with disabled KMS, leading to access of uninitialized data on driver
removal/unbinding and crashing kernel. Fix it by skipping shutting down
atomic core with unavailable KMS.
In the Linux kernel, the following vulnerability has been resolved:
ASoC: SDCA: fix NULL pointer dereference in sdca_dev_unregister_functions
sdca_dev_unregister_functions() iterates over all SDCA function
descriptors and calls sdca_dev_unregister() on each func_dev without
checking for NULL. When a function registration has failed partway
through, or the device cleanup races with probe deferral, func_dev
entries may be NULL, leading to a kernel oops:
BUG: kernel NULL pointer dereference, address: 0000000000000040
RIP: 0010:device_del+0x1e/0x3e0
Call Trace:
sdca_dev_unregister_functions+0x37/0x60 [snd_soc_sdca]
release_nodes+0x35/0xb0
devres_release_all+0x90/0x100
device_unbind_cleanup+0xe/0x80
device_release_driver_internal+0x1c1/0x200
bus_remove_device+0xc6/0x130
device_del+0x161/0x3e0
device_unregister+0x17/0x60
sdw_delete_slave+0xb6/0xd0 [soundwire_bus]
sdw_bus_master_delete+0x1e/0x50 [soundwire_bus]
...
sof_probe_work+0x19/0x30 [snd_sof]
This was observed on a Lenovo ThinkPad X1 Carbon G14 (Panther Lake)
with the SOF audio driver probe failing due to missing Panther Lake
firmware, causing the subsequent cleanup of SoundWire devices to
trigger the crash.
Fix this with three changes:
1) Add a NULL guard in sdca_dev_unregister() so that callers do not
need to pre-validate the pointer (defense in depth).
2) In sdca_dev_unregister_functions(), skip NULL func_dev entries
and clear func_dev to NULL after unregistration, making the
function idempotent and safe against double-invocation.
3) In sdca_dev_register_functions(), roll back all previously
registered functions when a later one fails, so the function
array is never left in a partially-populated state.
In the Linux kernel, the following vulnerability has been resolved:
slimbus: qcom-ngd-ctrl: Register callbacks after creating the ngd
When the remoteproc starts in parallel with the NGD driver being probed,
or the remoteproc is already up when the PDR lookup is being registered,
or in the theoretical event that we get an interrupt from the hardware,
these callbacks will operate on uninitialized data. This result in
issues to boot the affected boards.
One such example can be seen in the following fault, where
qcom_slim_ngd_ssr_pdr_notify() schedules work on the NULL ngd_up_work.
[ 21.858578] ------------[ cut here ]------------
[ 21.858745] WARNING: kernel/workqueue.c:2338 at __queue_work+0x5e0/0x790, CPU#2: kworker/2:2/116
...
[ 21.859251] Call trace:
[ 21.859255] __queue_work+0x5e0/0x790 (P)
[ 21.859265] queue_work_on+0x6c/0xf0
[ 21.859273] qcom_slim_ngd_ssr_pdr_notify+0x110/0x150 [slim_qcom_ngd_ctrl]
[ 21.859304] qcom_slim_ngd_ssr_notify+0x24/0x40 [slim_qcom_ngd_ctrl]
[ 21.859318] notifier_call_chain+0xa4/0x230
[ 21.859329] srcu_notifier_call_chain+0x64/0xb8
[ 21.859338] ssr_notify_start+0x40/0x78 [qcom_common]
[ 21.859355] rproc_start+0x130/0x230
[ 21.859367] rproc_boot+0x3d4/0x518
...
Move the enablement of interrupts, and the registration of SSR and PDR
until after the NGD device has been registered.
This could be further refined by moving initialization to the control
driver probe and by removing the platform driver model from the picture.
In the Linux kernel, the following vulnerability has been resolved:
mm/mincore: handle non-swap entries before !CONFIG_SWAP guard
mincore_swap() also fields migration/hwpoison entries (and shmem
swapin-error entries), which can exist on !CONFIG_SWAP builds when
CONFIG_MIGRATION or CONFIG_MEMORY_FAILURE is enabled. The
!IS_ENABLED(CONFIG_SWAP) guard ran before the non-swap-entry early return,
so mincore_pte_range() can spuriously WARN and report these pages
nonresident on !CONFIG_SWAP kernels.
Move the guard below the non-swap-entry check so only true swap entries
trip the WARN, and migration/hwpoison entries take the existing "uptodate
/ non-shmem" path.
In the Linux kernel, the following vulnerability has been resolved:
mm/damon/reclaim: handle ctx allocation failure
Patch series "mm/damon/{reclaim,lru_sort}: handle ctx allocation failures".
DAMON_RECLAIM and DAMON_LRU_SORT could dereference NULL pointers if their
damon_ctx object allocations fail. The bugs are expected to happen
infrequently because the allocations are arguably too small to fail on
common setups. But theoretically they are possible and the consequences
are bad. Fix those.
The issues were discovered [1] by Sashiko.
This patch (of 2):
DAMON_RECLAIM allocates the damon_ctx object for its kdamond in its init
function. damon_reclaim_enabled_store() wrongly assumes the allocation
will always succeed once tried. If the damon_ctx allocation was failed,
therefore, code execution reaches to damon_commit_ctx() while 'ctx' is
NULL. As a result, it dereferences the NULL 'ctx' pointer. Avoid the
NULL dereference by returning -ENOMEM if 'ctx' is NULL.
In the Linux kernel, the following vulnerability has been resolved:
mm/damon/lru_sort: handle ctx allocation failure
DAMON_LRU_SORT allocates the damon_ctx object for its kdamond in its init
function. damon_lru_sort_enabled_store() wrongly assumes the allocation
will always succeed once tried. If the damon_ctx allocation was failed,
therefore, code execution reaches to damon_commit_ctx() while 'ctx' is
NULL. As a result, it dereferences the NULL 'ctx' pointer. Avoid the
NULL dereference by returning -ENOMEM if 'ctx' is NULL.