In the Linux kernel, the following vulnerability has been resolved:
libceph: Fix slab-out-of-bounds access in auth message processing
If a (potentially corrupted) message of type CEPH_MSG_AUTH_REPLY
contains a positive value in its result field, it is treated as an
error code by ceph_handle_auth_reply() and returned to
handle_auth_reply(). Thereafter, an attempt is made to send the
preallocated message of type CEPH_MSG_AUTH, where the returned value is
interpreted as the size of the front segment to send. If the result
value in the message is greater than the size of the memory buffer
allocated for the front segment, an out-of-bounds access occurs, and
the content of the memory region beyond this buffer is sent out.
This patch fixes the issue by treating only negative values in the
result field as errors. Positive values are therefore treated as success
in the same way as a zero value. Additionally, a BUG_ON is added to
__send_prepared_auth_request() comparing the len parameter to
front_alloc_len to prevent sending the message if it exceeds the bounds
of the allocation and to make it easier to catch any logic flaws leading
to this.
In the Linux kernel, the following vulnerability has been resolved:
wifi: b43: enforce bounds check on firmware key index in b43_rx()
The firmware-controlled key index in b43_rx() can exceed the dev->key[]
array size (58 entries). The existing B43_WARN_ON is non-enforcing in
production builds, allowing an out-of-bounds read.
Make the B43_WARN_ON check enforcing by dropping the frame when the
firmware returns an invalid key index.
In the Linux kernel, the following vulnerability has been resolved:
ipmi:si: Return state to normal if message allocation fails
There were places where nothing would get started if a message
allocation failed, so the driver needs to return to normal state.
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Fix shadow paging use-after-free due to unexpected GFN
The shadow MMU computes GFNs for direct shadow pages using sp->gfn plus
the SPTE index. This assumption breaks for shadow paging if the guest
page tables are modified between VM entries (similar to commit
aad885e77496, "KVM: x86/mmu: Drop/zap existing present SPTE even
when creating an MMIO SPTE", 2026-03-27). The flow is as follows:
- a PDE is installed for a 2MB mapping, and a page in that area is
accessed. KVM creates a kvm_mmu_page consisting of 512 4KB pages;
the kvm_mmu_page is marked by FNAME(fetch) as direct-mapped because
the guest's mapping is a huge page (and thus contiguous).
- the PDE mapping is changed from outside the guest.
- the guest accesses another page in the same 2MB area. KVM installs
a new leaf SPTE and rmap entry; the SPTE uses the "correct" GFN
(i.e. based on the new mapping, as changed in the previous step) but
that GFN is outside of the [sp->gfn, sp->gfn + 511] range; therefore
the rmap entry cannot be found and removed when the kvm_mmu_page
is zapped.
- the memslot that covers the first 2MB mapping is deleted, and the
kvm_mmu_page for the now-invalid GPA is zapped. However, rmap_remove()
only looks at the [sp->gfn, sp->gfn + 511] range established in step 1,
and fails to find the rmap entry that was recorded by step 3.
- any operation that causes an rmap walk for the same page accessed
by step 3 then walks a stale rmap and dereferences a freed kvm_mmu_page.
This includes dirty logging or MMU notifier invalidations (e.g., from
MADV_DONTNEED).
The underlying issue is that KVM's walking of shadow PTEs assumes that
if a SPTE is present when KVM wants to install a non-leaf SPTE, then the
existing kvm_mmu_page must be for the correct gfn. Because the only way
for the gfn to be wrong is if KVM messed up and failed to zap a SPTE...
which shouldn't happen, but *actually* only happens in response to a
guest write.
That bug dates back literally forever, as even the first version of KVM
assumes that the GFN matches and walks into the "wrong" shadow page.
However, that was only an imprecision until 2032a93d66fa ("KVM: MMU:
Don't allocate gfns page for direct mmu pages") came along.
Fix it by checking for a target gfn mismatch and zapping the existing
SPTE. That way the old SP and rmap entries are gone, KVM installs
the rmap in the right location, and everyone is happy.
In the Linux kernel, the following vulnerability has been resolved:
net: caif: clear client service pointer on teardown
`caif_connect()` can tear down an existing client after remote shutdown by
calling `caif_disconnect_client()` followed by `caif_free_client()`.
`caif_free_client()` releases the service layer referenced by
`adap_layer->dn`, but leaves that pointer stale.
When the socket is later destroyed, `caif_sock_destructor()` calls
`caif_free_client()` again and dereferences the freed service pointer.
Clear the client/service links before releasing the service object so
repeated teardown becomes harmless.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: aloop: Fix peer runtime UAF during format-change stop
loopback_check_format() may stop the capture side when playback starts
with parameters that no longer match a running capture stream. Commit
826af7fa62e3 ("ALSA: aloop: Fix racy access at PCM trigger") moved
the peer lookup under cable->lock, but the actual snd_pcm_stop() still
runs after dropping that lock.
A concurrent close can clear the capture entry from cable->streams[] and
detach or free its runtime while the playback trigger path still holds a
stale peer substream pointer.
Keep a per-cable count of in-flight peer stops before dropping
cable->lock, and make free_cable() wait for those stops before
detaching the runtime. This preserves the existing behavior while
making the peer runtime lifetime explicit.
In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Inject #UD for INVLPGA if EFER.SVME=0
INVLPGA should cause a #UD when EFER.SVME is not set. Add a check to
properly inject #UD when EFER.SVME=0.
[sean: tag for stable@]
In the Linux kernel, the following vulnerability has been resolved:
fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info
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.
In the Linux kernel, the following vulnerability has been resolved:
ibmasm: fix heap over-read in ibmasm_send_i2o_message()
The ibmasm_send_i2o_message() function uses get_dot_command_size() to
compute the byte count for memcpy_toio(), but this value is derived from
user-controlled fields in the dot_command_header (command_size: u8,
data_size: u16) and is never validated against the actual allocation size.
A root user can write a small buffer with inflated header fields, causing
memcpy_toio() to read up to ~65 KB past the end of the allocation into
adjacent kernel heap, which is then forwarded to the service processor
over MMIO.
Silently clamping the copy size is not sufficient: if the header fields
claim a larger size than the buffer, the SP receives a dot command whose
own header is inconsistent with the I2O message length, which can cause
the SP to desynchronize. Reject such commands outright by returning
failure.
Validate command_size before calling get_mfa_inbound() to avoid leaking
an I2O message frame: reading INBOUND_QUEUE_PORT dequeues a hardware
frame from the controller's free pool, and returning without a
corresponding set_mfa_inbound() call would permanently exhaust it.
Additionally, clamp command_size to I2O_COMMAND_SIZE before the
memcpy_toio() so the MMIO write stays within the I2O message frame,
consistent with the clamping already performed by outgoing_message_size()
for the header field.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: ctxfi: Add fallback to default RSR for S/PDIF
spdif_passthru_playback_get_resources() uses atc->pll_rate as the RSR
for the MSR calculation loop. However, pll_rate is only updated in
atc_pll_init() and not in hw_pll_init(), so it remains 0 after the
card init.
When spdif_passthru_playback_setup() skips atc_pll_init() for
32000 Hz, (rsr * desc.msr) always becomes 0, causing the loop to spin
indefinitely.
Add fallback to use atc->rsr when atc->pll_rate is 0. This reflects
the hardware state, since hw_card_init() already configures the PLL
to the default RSR.