KVM: SEV: Nullify "have run CPUs" mask pointer when freeing it
In the Linux kernel, the following vulnerability has been resolved:
KVM: SEV: Nullify "have run CPUs" mask pointer when freeing it
Nullify have_run_cpus when freeing the mask, particularly in the error path
of __sev_guest_init(), so that KVM doesn't have to subtly use sev->active
to track whether or not the mask has been freed. As pointed out by Sashiko,
blindly freeing the mask in sev_vm_destroy() results in a double-free if
the mask is freed if __sev_guest_init() fails.
Throw the logic in a helper as nullifying the pointer is frustratingly
difficult and weird due to have_run_cpus being a single-entry array when
CPUMASK_OFFSTACK=n. Deli
KVM: SEV: Do cache maintenance on the source VM *before* clearing SEV state
In the Linux kernel, the following vulnerability has been resolved:
KVM: SEV: Do cache maintenance on the source VM *before* clearing SEV state
Explicitly flush caches after intra-host migration before clearing "SEV
active" on the source VM, as doing cache maintenance afterwards creates a
tiny window where memory reclaim could return memory to the host without
performing a cache flush, e.g. as pointed out by Sashiko:
CPU1 in sev_migrate_from():
src->active = false;
CPU2 running concurrent unmap:
Since active is false, the automatic cache flush in
sev_guest_memory_reclaimed is skipped.
The host frees and reallocates the
KVM: x86/mmu: Bail from shadow walks if the root is invalid or a dummy
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86/mmu: Bail from shadow walks if the root is invalid or a dummy
When walking shadow page tables, immediately terminate the walk if the root
is a "dummy" root, i.e. a root whose top-level page table is backed by the
zero page, but otherwise doesn't exist. If memslot creation races with a
stage-2 page fault (EPT violation or #NPF) from L2, then if the stars align,
KVM will attempt to walk shadow page tables using the zero page and hit a
NULL pointer deref.
BUG: kernel NULL pointer dereference, address: 0000000000000021
#PF: supervisor read access in kernel mode
KVM: SVM: Use the active VMCB's MSR bitmap when checking if MSR is intercepted
In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Use the active VMCB's MSR bitmap when checking if MSR is intercepted
Use the MSR permission bitmap of the active VMCB instead of assuming that
KVM is always using vmcb02's bitmap when L2 is active, as KVM uses msrpm02
if and only if L1 wants to intercept MSR accesses, i.e. if and only if KVM
needs to merge msprm01 with msrpm12.
Don't bother tracking the virtual address of the bitmap that's being used,
as __va() is cheap on x86, and caching the virtual address would introduce
yet another source of potentially stale information.
KVM: SVM: Preserve TLB control (i.e. pending TLB flush) on failed VMRUN
In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Preserve TLB control (i.e. pending TLB flush) on failed VMRUN
Don't reset the VMCB's TLB control back to "do nothing" on a failed VMRUN,
as empirical testing shows that the CPU performs the requested TLB flush if
and only if VMRUN is successful, i.e. clearing TLB control on a failed
VMRUN effectively drops a TLB flush.
Explicitly track the need to flush all ASIDs on a per-CPU basis, as the
ASID reuse condition is tied to the pCPU, not to the vCPU. As a bonus,
this also obviates the need to avoid clobbering FLUSH_ALL_ASID with
TLB_CONTROL_FLUSH_ASID, e.g. in svm_
KVM: SVM: Update control fields on #VMEXIT if and only if VMRUN succeeded
In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Update control fields on #VMEXIT if and only if VMRUN succeeded
Leave control.erap_ctl and control.clean as-is in the VMCS if VMRUN fails,
because as per AMD:
there's no explicit architectural guarantee about the behavior in the
presence of VMRUN failures. So the best thing to do would be to assume
that if VMRUN fails, the actions requested in the control fields may not
have been performed.
KVM: arm64: Apply the fine-grained UNDEFs without FEAT_FGT
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Apply the fine-grained UNDEFs without FEAT_FGT
FGUs don't actually require hardware support, so don't gate fgt trap
config insertion on FGT. This is the only action required to allow FGUs
always, as kvm_calculate_traps() already computes the FGU bits with or
without FEAT_FGT.
This also fixes a spurious WARN when a TLBI OS is run on a guest in vEL1
without FEAT_TLBIOS on non FEAT_FGT hardware. In this configuration the
course-grained HCR_EL2.TTLBOS trap reaches the handler handle_tlbi_el1(),
which expects an EL1 TLBI only from vEL2. With FGUs enabled the UNDEF
w
KVM: arm64: vgic: Take a refcount on IRQs referenced by last_lr_irq
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: vgic: Take a refcount on IRQs referenced by last_lr_irq
Referencing the last interrupt inserted in an LR is rather fragile, as
this interrupt can vanish if a concurrently unmapped LPI.
Solve this by bumping up the refcount on the interrupt when populating
last_lr_irq, and drop it at vgic_prune_ap_list() time, when LPIs are
being reclaimed.
wifi: cw1200: fix TX padding OOB read leaking heap data to device
In the Linux kernel, the following vulnerability has been resolved:
wifi: cw1200: fix TX padding OOB read leaking heap data to device
The TX path rounds the transfer size up to the bus alignment
(align_size(), up to 511 bytes for SDIO, 1 byte for SPI) but sends
the padded length straight from the frame buffer, which has no room
reserved for the padding. cw1200_data_write() therefore reads past
the end of the frame and the bus transfer carries those bytes to the
device. A bogus device can collect up to 511 bytes of kernel heap
data per TX frame.
The RX path does not have this problem: it allocates the skb with
the aligned length (alloc_le
In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlegacy: 3945: free EEPROM data on remove
il3945_pci_probe() calls il_eeprom_init(), which allocates memory for
the EEPROM data. The probe failure paths release this allocation with
il_eeprom_free(), but the remove path does not free it after a
successful probe.
As a result, the EEPROM data is leaked when the PCI device is removed.
Free the EEPROM data in il3945_pci_remove() before releasing the
mac80211 hardware structure.
This issue was found by manual code inspection.
wifi: mac80211: count only matching reservations in reserved switch
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: count only matching reservations in reserved switch
ieee80211_vif_use_reserved_switch() validates a replacement by counting
assigned links on ctx->replace_ctx and treating reservations too
broadly. A link can still be assigned to the old channel context while
holding a reservation that belongs to a different replacement
operation.
That can make the current replacement appear complete too early. If
another link finalizes first, the function can free the
WILL_BE_REPLACED chanctx while the unmatched link and driver still use
it, leading to a use-after-free in
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: keep paired old chanctx alive
An in-place replacement keeps reciprocal replace_ctx pointers between
the old WILL_BE_REPLACED chanctx and the new REPLACES_OTHER chanctx.
However, the early free paths only consider assigned and reserved link
users when deciding whether to free the old chanctx.
That lets the old chanctx be freed too early while the replacement
partner still points back to it, either when the last assigned link is
released or when that link successfully reassigns to another existing
context. Later unreserve and switch-finalization paths can the
wifi: mac80211: shut down RX BA session timer on teardown
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: shut down RX BA session timer on teardown
Tearing down an RX BA session can leave the session timer queued on a
freed tid_rx. Later timer-wheel processing and the timer callback itself
then run against freed memory.
An RX BAR handler can dereference tid_rx under RCU before teardown
unpublishes it and stay in its read-side critical section while teardown
deletes the session timer. The stale handler can then rearm the timer
after timer_delete_sync() returns and before the RCU callback frees
tid_rx.
Use timer_shutdown_sync() so rearm attempts become ineffecti
wifi: mac80211: drain PS delivery work during station teardown
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: drain PS delivery work during station teardown
Removing an AP or mesh station can notify the driver and wake TXQs after
the station has already been removed from the driver, and can update
num_sta_ps and the power-save queues after station cleanup has purged
them.
sta_deliver_ps_frames() tests sta->dead only before it starts delivery. A
worker that passes that test can be delayed while teardown sets sta->dead
and removes the station from the driver; when it resumes it still runs the
full delivery.
The existing cancel_work_sync() sits near the end of
__clea
wifi: mac80211: account proxy paths against the mesh path limit
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: account proxy paths against the mesh path limit
Proxy-path churn can drive the interface path counter negative and let
later mesh path additions exceed MESH_MAX_MPATHS.
mesh_path_free_rcu() decrements the interface mpaths counter for entries
from both the mesh and proxy path tables, but mpp_path_add() never
reserves a slot in that counter. Removing or expiring a proxy path
therefore returns a slot that was never charged.
mesh_path_add() uses the same counter to enforce MESH_MAX_MPATHS, so once
it falls below the number of installed paths the limit no longe
wifi: mac80211: keep fallback association elements alive
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: keep fallback association elements alive
Associating to a non-transmitted MBSSID profile reads freed memory while
determining the operating channel and applying HT capabilities.
When an association response omits WMM, HT, or VHT information,
ieee80211_assoc_config_link() parses the cached BSS IEs and copies the
missing element pointers out of that fallback parse. For a
non-transmitted MBSSID profile those pointers refer to merged-profile
storage owned by the parse object, and the fallback block frees that
object at its end. The copied pointers are used afte
wifi: mac80211: minstrel_ht: validate fixed rate index
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: minstrel_ht: validate fixed rate index
The fixed_rate_idx debugfs file is a plain u32 attribute, so any value
can be written to it. minstrel_ht_update_stats() then copies the value
into mi->max_tp_rate[] and mi->max_prob_rate, and
minstrel_ht_set_rate() uses MI_RATE_GROUP()/MI_RATE_IDX() to index
minstrel_mcs_groups[] (42 entries) and mi->groups[].rates[] (10 entries)
with it.
Writing e.g. 65535 selects group 4095 and rate index 15, far outside
both arrays. The out-of-bounds entries are dereferenced and updated as
struct minstrel_rate_stats (retry counts,
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: reject invalid 320 MHz CSA bandwidth
The HT/VHT channel definition validator can receive a 320 MHz
bandwidth indication from a received CSA frame on a non-6 GHz link.
It warns for this unsupported width but continues with an uninitialized
vht_operation.chan_width, which is then read by
ieee80211_chandef_vht_oper(). With panic_on_warn enabled, this lets a
received frame panic the kernel.
Reject the channel definition before entering the VHT operation
conversion. This preserves the existing CSA fallback while avoiding
both the warning and the uninitialized re
wifi: mac80211: release mesh path quota on failed additions
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: release mesh path quota on failed additions
Repeated failed or duplicate mesh path additions can exhaust
MESH_MAX_MPATHS while the path table holds fewer paths, which stops new
paths to reachable destinations from being created.
mesh_path_add() reserves a slot before allocating and inserting a path.
If allocation fails, the function returns without releasing the slot. If
the rhashtable insertion reports an error or an existing destination, the
function discards its candidate but retains the reservation. No new path
is installed in any of these cases.
Relea
wifi: mac80211: set info->band for 802.3 encap offload frames
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: set info->band for 802.3 encap offload frames
Unlike the 802.11 TX paths, ieee80211_8023_xmit() does not set
info->band from the channel context on non-MLD interfaces. It stays at
0, so ieee80211_get_tx_rates() uses the wrong band for these frames.
Set it the same way as ieee80211_build_hdr(): drop the frame if there is
no channel context, and leave the band at 0 on MLD interfaces.