In the Linux kernel, the following vulnerability has been resolved:
usb: usblp: fix heap leak in IEEE 1284 device ID via short response
usblp_ctrl_msg() collapses the usb_control_msg() return value to
0/-errno, discarding the actual number of bytes transferred. A broken
printer can complete the GET_DEVICE_ID control transfer short and the
driver has no way to know.
usblp_cache_device_id_string() reads the 2-byte big-endian length prefix
from the response and trusts it (clamped only to the buffer bounds).
The buffer is kmalloc(1024) at probe time. A device that sends exactly
two bytes (e.g. 0x03 0xFF, claiming a 1023-byte ID) leaves
device_id_string[2..1022] holding stale kmalloc heap.
That stale data is then exposed:
- via the ieee1284_id sysfs attribute (sprintf("%s", buf+2), truncated
at the first NUL in the stale heap), and
- via the IOCNR_GET_DEVICE_ID ioctl, which copy_to_user()s the full
claimed length regardless of NULs, up to 1021 bytes of uninitialized
heap, with the leak size chosen by the device.
Fix this up by just zapping the buffer with zeros before each request
sent to the device.
In the Linux kernel, the following vulnerability has been resolved:
8021q: delete cleared egress QoS mappings
vlan_dev_set_egress_priority() currently keeps cleared egress
priority mappings in the hash as tombstones. Repeated set/clear cycles
with distinct skb priorities therefore accumulate mapping nodes until
device teardown and leak memory.
Delete mappings when vlan_prio is cleared instead of keeping tombstones.
Now that the egress mapping lists are RCU protected, the node can be
unlinked safely and freed after a grace period.
In the Linux kernel, the following vulnerability has been resolved:
ipmi: Check event message buffer response for bad data
The event message buffer response data size got checked later when
processing, but check it right after the response comes back. It
appears some BMCs may return an empty message instead of an error
when fetching events.
There are apparently some new BMCs that make this error, so we need to
compensate.
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:
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:
mm: fix deferred split queue races during migration
migrate_folio_move() records the deferred split queue state from src and
replays it on dst. Replaying it after remove_migration_ptes(src, dst, 0)
makes dst visible before it is requeued, so a concurrent rmap-removal path
can mark dst partially mapped and trip the WARN in deferred_split_folio().
Move the requeue before remove_migration_ptes() so dst is back on the
deferred split queue before it becomes visible again.
Because migration still holds dst locked at that point, teach
deferred_split_scan() to requeue a folio when folio_trylock() fails.
Otherwise a fully mapped underused folio can be dequeued by the shrinker
and silently lost from split_queue.
[ziy@nvidia.com: move the comment]
In the Linux kernel, the following vulnerability has been resolved:
misc: ibmasm: fix OOB MMIO read in ibmasm_handle_mouse_interrupt()
ibmasm_handle_mouse_interrupt() performs an out-of-bounds MMIO read
when the queue reader or writer index from hardware exceeds
REMOTE_QUEUE_SIZE (60).
A compromised service processor can trigger this by writing an
out-of-range value to the reader or writer MMIO register before
asserting an interrupt. Since writer is re-read from hardware on
every loop iteration, it can also be set to an out-of-range value
after the loop has already started.
The root cause is that get_queue_reader() and get_queue_writer() return
raw readl() values that are passed directly into get_queue_entry(),
which computes:
queue_begin + reader * sizeof(struct remote_input)
with no bounds check. This unchecked MMIO address is then passed to
memcpy_fromio(), reading 8 bytes from unintended device registers.
For sufficiently large values the address falls outside the PCI BAR
mapping entirely, triggering a machine check exception.
Fix by checking both indices against REMOTE_QUEUE_SIZE at the top of
the loop body, before any call to get_queue_entry(). On an out-of-range
value, reset the reader register to 0 via set_queue_reader() before
breaking, so that normal queue operation can resume if the corrupted
hardware state is transient.