The GICv3 secondary_init() callback can fail while discovering or
waking a Redistributor, enabling LPIs, or setting up an ITS collection.
gic_init_secondary_cpu() currently discards that status. start_secondary()
then marks the CPU online even though its per-CPU GIC interface may be
unusable.
Return the callback status through the common GIC layer. Have
start_secondary() report the failure and stop the affected CPU before it
updates system features or is added to cpu_online_map.
Fixes: bc183a0235 ("xen/arm: Add support for GIC v3")
Signed-off-by: Mykola Kvach <mykola_kvach@epam.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
(cherry picked from commit 0102b592f4)
process_domain_node() parses "xen,static-mem" regardless of
CONFIG_STATIC_MEMORY. With the feature off, init_staticmem_pages() is a
no-op stub, so boot carries on until construct_domU() reaches the
ASSERT_UNREACHABLE() stubs of allocate_static_memory() /
assign_static_memory_11(): a debug build trips the assertion, a production
build gives the domain no memory at all.
Bail out at parse time instead, like process_shm_node() already does for
CONFIG_STATIC_SHM.
Fixes: 41c031ff43 ("xen/arm: introduce domain on Static Allocation")
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Acked-by: Bertrand Marquis <bertrand.marquis@arm.com>
(cherry picked from commit e888192d13)
PSR_GUEST64_INIT currently masks SError, IRQ and FIQ, but leaves debug
exceptions unmasked. Both the AArch64 Linux boot protocol and PSCI entry
requirements expect PSTATE.DAIF to be masked.
Add PSR_DBG_MASK to PSR_GUEST64_INIT. This fixes the initial AArch64 guest
entry state as well as virtual PSCI CPU_ON and SYSTEM_SUSPEND resume entry.
Signed-off-by: Mykola Kvach <mykola_kvach@epam.com>
Reviewed-by: Julien Grall <julien@xen.org>
(cherry picked from commit ad8663a75a)
Recent Clang objects to types differing between alias and aliasee. Accept
the unnecessary overhead and make the two compat stubs real functions.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
master commit: 5df9425a73
master date: 2026-09-09 14:15:15 +0200
.data.rel.ro really is merely a special case of .rodata: r/o data, but
with runtime relocations (not relevant to Xen), i.e. r/o only after
relocations were performed (by the dynamic loader).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: f7eab298bb
master date: 2026-09-08 09:50:48 +0200
Recent Clang complains about the "debug" static variable only ever being
written to. Drop it and the command line option controlling it.
Fixes: 19ab8356ab ("tools: remove support for running a guest with qemu-traditional")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Roger Pau Monné <roger@xenproject.org>
master commit: f907784c32
master date: 2026-09-07 14:11:35 +0200
The requested PCI segment needs including in the call to
xsm_pci_config_permission(). Otherwise in a multi-segment system we can check
the perimssions on one device but operate on a different one.
This is only not a vulnerability because pci_conf_write_intercept() is only
reachable by the hardware domain.
Fixes: 300bb048ca ("x86/PCI: make all config space writes subject to XSM checking")
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: b4a671acf1
master date: 2026-09-03 09:45:16 +0100
sched_init_vcpu() calls init_timer() for a vcpu's periodic_timer,
singleshot_timer and poll_timer before it can fail -- these
become live, linked into their target pCPU's per-cpu timer list
regardless of what happens next. If the sched_alloc_udata() call
further down then fails, the function frees the sched_unit via
sched_free_unit() and returns 1, but never unlinks these three
timers.
The caller, vcpu_create(), makes this worse: on sched_init_vcpu()
returning nonzero it jumps to fail_wq, skipping fail_sched and
thus sched_destroy_vcpu() -- the only function on this path that
calls kill_timer() on them. vcpu_destroy() then frees the vcpu,
and the three timers embedded in it, while they are still linked
into that shared list.
This silently corrupts that list. It only shows up later, when
something else touches a neighboring timer: sched_move_domain()
crashed with "Assertion 'entry->prev->next == entry' failed" on a
completely unrelated, valid vcpu's timer.
Call sched_destroy_vcpu() in sched_init_vcpu()'s own failure
branch instead of sched_free_unit(), so it doesn't depend
on the caller reaching sched_destroy_vcpu() to undo what it set
up itself. sched_destroy_vcpu() assumes unit->priv is set, which
is not the case here, so make it only free the udata and remove
the unit if unit->priv in non-NULL.
Fixes: d884b10778 ("Domain creation/destruction cleanups.")
Signed-off-by: Furkan Caliskan <frn1furkan10@gmail.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
master commit: 2565341135
master date: 2026-09-01 10:02:13 +0200
It's possible for domains to generate unaligned PCI config space accesses
when using ECAM, and hence vPCI should support those at least for the
hardware domain. Such unaligned accesses to the PCI config space have been
reported to come from ACPI logic.
Relax the checking in vpci_access_allowed() to allow such accesses for the
hardware domain, and fix the handling in pci_conf_{read,write}{16,32}() to
fulfill them using MMCFG.
MMCFG regions are identity exposed to the hardware domain, and hence such
unaligned accesses can only come as a result of the host having MMCFG in the
first place, as otherwise MMCFG won't be exposed to the hardware domain
either.
Note that vpci_ecam_{read,write}() already refuse accesses that cross a
device boundary unconditionally.
Reported-by: Jason Andryuk <jason.andryuk@amd.com>
Signed-off-by: Roger Pau Monné <roger@xenproject.org>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stewart Hildebrand <stewart.hildebrand@amd.com>
master commit: 79175b1390
master date: 2026-08-26 11:50:42 +0200
oxenstored maintains two datastructures about watches; one global trie, and
one hashtable tracked per domain. Both need keeping in sync, and right now
the global trie is not emptied when a xenbus reconnect is requested.
This is basically the same bug as XSA-330, commit 491a077ed4
("tools/ocaml/xenstored: delete watch from trie too when resetting watches"),
just tickled via another path.
Arrange for both Process.do_reset_watches() and Process.do_reconnect() to
share a common codepath for the resetting of watches and transactions.
Notably, this means that the latter now calls Connections.del_watches() which
clears the global trie too.
Connections.del_watches() already calls Connection.del_watches() so remove the
re-clearing of the state from Connection.do_reconnect().
Move History.trim() into reset_watches_and_transactions() so it's on the
common path, and place it after removing the transactions rather than before.
This is part of XSA-512 / CVE-2026-79604.
Reported-by: David Korczynski <David@Adalogics.com>
Fixes: 674ad2be40 ("xenstore: extend the xenstore ring with a 'closing' signal")
Signed-off-by: Andrii Sultanov <andriy.sultanov@vates.tech>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Andrii Sultanov <andriy.sultanov@vates.tech>
(cherry picked from commit a2ca4f8b98)
The logic flow here is complicated. In preparation to fix a bug, factor out
reconnecting a xenbus connection, and fold History.reconnect into it's single
caller.
No functional change.
This is part of XSA-512 / CVE-2026-79604.
Signed-off-by: Andrii Sultanov <andriy.sultanov@vates.tech>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Andrii Sultanov <andriy.sultanov@vates.tech>
(cherry picked from commit 9c5a46b120)
The current way in which idle TLB flush and TLB flushing when allocating a
page are done allows for the scrubbing to be done ahead of the TLB flush.
A PV domain can still have a TLB entry for the page after scrubbing, and
hence it may be able to modify it. Such unintended page accessing allows
domains to possibly exchange information even when `xsm=silo scrub-domheap`
are in effect.
Remove the MEMF_no_tlbflush memory allocation flag, and reorder the
flushing so it's always done ahead of the scrubbing in
alloc_{,color_}heap_pages(). The sole user of MEMF_no_tlbflush is
populate_physmap(), and given the constrains above it's no longer safe
to defer the flush, hence the flag removal and the folding of the flush in
the allocator function itself.
This is XSA-511 / CVE-2026-79603.
Fixes: 24f1a58d19 ("mm: option to _always_ scrub freed domheap pages")
Signed-off-by: Roger Pau Monné <roger@xenproject.org>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit ed7e656e6c)
hvm_io_intercept() can return X86EMUL_RETRY, and as such it needs to be
handled in the switch in hvmemul_do_io() to avoid triggering the BUG() from
the default case.
Reset the vCPU state to no in-flight IOREQ and return X86EMUL_RETRY so that
the access is retried.
This is XSA-510 / CVE-2026-79602.
Reported-by: Jiqian Chen <Jiqian.Chen@amd.com>
Signed-off-by: Roger Pau Monné <roger@xenproject.org>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 62aff07326)
DMs may invoke XEN_DOMCTL_bind_pt_irq for domains already under
destruction. When XEN_DOMCTL_bind_pt_irq is invoked after
pci_release_devices() (invoked from underneath domain_kill()) had already
completed, it would allocate hvm_domain_irq(d)->dpci anew, without that
ever being freed during subsequent domain cleanup.
Leverage evtchn_destroy()'s kind-of-spin-barrier, allowing to simply check
->is_dying with the domain's event lock held.
This is XSA-509 / CVE-2026-62437.
Fixes: 7a26b541a2 ("vtd: Dynamically allocate IRQ-tracking structures, only for those")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
(cherry picked from commit 328a146143)
Right now it's only checked in setup_p4_watchdog(), and not in
setup_p6_watchdog().
Perform the check in the common Intel path in setup_apic_nmi_watchdog(), and
pass misc_enable as a parameter into setup_p4_watchdog() to avoid reading it
twice.
Fixes: 0dfba864fb ("NMI watchdog support in Xen.")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: dfb428cb11
master date: 2026-08-18 12:51:08 +0100
It used to be the case that cpu_data[] inherited the BSP's cpuid_level until
the AP had calculated it itself. Following the rework, cpuid_level has a
placeholder 1 until it is calculated properly.
setup_apic_nmi_watchdog() happens to be called on the BSP after SMP bring-up,
meaning that the first call is on CPU1. It is also positioned in the window
where cpu_data[] is wrong.
As a result, setup_p6_watchdog()'s one-time calculation of the performance
counter width falls back into Pentium compatibility mode assuming 32bit
counters. This causes a watchdog NMI which is delayed a little (e.g. from an
SMI), to appear as if it hadn't overflowed, and therefore be considered as not
a watchdog NMI. On systems where unknown NMIs are treated as fatal, this
results in a spurious crash.
Switch setup_p6_watchdog() to use boot_cpu_data.cpuid_level, which is how this
is checked almost everywhere else.
core2_vpmu_init() used the same pattern to look at leaf 0xa. Despite being
init code and only running on the BSP, {boot,current}_cpu_data are different
objects, so switch it over to checking boot_cpu_data.cpuid_level too.
Fixes: 7126b7f806 ("x86/CPU: re-work populating of cpu_data[]")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: dc5a77c6c4
master date: 2026-08-17 18:46:08 +0100
Radix trees are in principle usable as soon as memory allocation works.
(Radix trees with only index 0 populated are usable even earlier.) If only
there wasn't height_to_maxindex[], which is filled only by a pre-SMP
initcall. The benefit of this array is rather limited - the calculations
done by __maxindex() can as well be done by radix_tree_maxindex(); the
overhead isn't all this high.
This was found by UBSAN on a multi-segment system:
(XEN) UBSAN: Undefined behaviour in common/radix-tree.c:83:27
(XEN) index 12 is out of range for type 'long unsigned int [12]'
...
(XEN) Xen call trace:
(XEN) [<ffff82d040323f9c>] R common/ubsan/ubsan.c#ubsan_epilogue+0xa/0xd5
(XEN) [<ffff82d040324d91>] F __ubsan_handle_out_of_bounds+0x9d/0xd4
(XEN) [<ffff82d04029265a>] F radix_tree_insert+0x24d/0x570
(XEN) [<ffff82d04037ac3e>] F drivers/passthrough/pci.c#alloc_pseg+0xc4/0x165
(XEN) [<ffff82d040a3b526>] F pci_add_segment+0xc/0x1b
(XEN) [<ffff82d040a5ad1b>] F acpi_parse_mcfg+0x29b/0x344
(XEN) [<ffff82d040a3f612>] F acpi_table_parse+0x5d/0x92
(XEN) [<ffff82d040a5bf55>] F acpi_mmcfg_init+0x3a2/0x71d
(XEN) [<ffff82d040a71ba6>] F pci_setup+0x17/0x29
(XEN) [<ffff82d040a784d0>] F __start_xen+0x394c/0x4ed8
(XEN) [<ffff82d040423057>] F __high_start+0xb7/0xb8
Fixes: 21844b0e32 ("PCI multi-seg: introduce notion of PCI segments")
Fixes: 8dc6738dbb ("Update radix-tree.[ch] from upstream Linux to gain RCU awareness")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 1077a93425
master date: 2026-08-05 12:00:17 +0200
The size passed to array_index_nospec() in evtchn_fifo_word_from_port()
doesn't match the value it is meant to clamp.
Fix it by clamping the port to a safe interval and use that value to
calculate the event_array[] index.
Fixes: 443d3ab6da ("evtchn: block speculative out-of-bound accesses")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 3a6cb6aae4
master date: 2026-08-03 09:50:07 +0200
With the introduction of core scheduling, cpus not used by any cpupool
have been switched to use the very simple idle scheduler instead of the
default scheduler.
Trying to obtain diagnostic scheduling data via the "r" debug key is
scanning through all cpupools using the per-cpupool scheduler to print
the related data. Unfortunately the switch to use the idle scheduler
for free cpus wasn't reflected in schedule_dump(), causing the default
scheduler's dump_cpu_state callback to be used for free cpus.
This causes NULL dereferences in case the default scheduler is one of
credit or null.
Fix that by using the idle scheduler instead of the default scheduler
for free cpus. Note that it is fine for a scheduler to have no
dump_cpu_state callback.
Fixes: f855dd9625 ("sched: add minimalistic idle scheduler for free cpus")
Reported-by: Dietmar Hahn <dietmar.hahn@fujitsu.com>
Tested-by: Dietmar Hahn <dietmar.hahn@fujitsu.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: f38e8cb85a
master date: 2026-07-29 14:41:22 +0100
schedule_cpu_rm() clears the cpupool pointer of the scheduling
resource before calling sched_deinit_pdata():
sr->cpupool = NULL;
...
sched_deinit_pdata(data->old_ops, data->ppriv_old, cpu);
For RTDS, rt_deinit_pdata() calls move_repl_timer() when the
replenishment timer lives on the cpu being removed, and
move_repl_timer() dereferences get_sched_res(old_cpu)->cpupool
without checking it for NULL. Removing a pCPU owning the timer from
an RTDS cpupool therefore dereferences NULL + 0x10 (the res_valid
member) and panics:
(XEN) Data Abort Trap. Syndrome=0x1c28005
(XEN) Walking Hypervisor VA 0x10 on CPU0 via TTBR ...
(XEN) Xen call trace:
(XEN) [<...>] find_next_bit+0x74/0xa8 (PC)
(XEN) [<...>] rt.c#move_repl_timer+0xb8/0xec (LR)
(XEN)
(XEN) Panic on CPU 0:
(XEN) CPU0: Unexpected Trap: Data Abort
Reproducer, on any host with at least 2 pCPUs and RTDS compiled in
(observed on arm64, but the path is common code):
xl cpupool-create name="test" sched="rtds"
xl cpupool-cpu-remove Pool-0 1
xl cpupool-cpu-add test 1
xl cpupool-cpu-remove test 1
The last command moves the RTDS replenishment timer to cpu1 (first
and only cpu of the pool) and then removes cpu1, hitting the NULL
dereference in the sched_deinit_pdata() callback.
Use the cpupool back-pointer of the scheduler instead of the one of
the scheduling resource. It is set by cpupool_create() before any
pCPU can be assigned to the pool and stays valid for the whole
lifetime of the scheduler, so it is still available when
rt_deinit_pdata() runs. Other schedulers already rely on it the same
way, e.g. credit2 in cpu_add_to_runqueue().
Fixes: b6f5334aea ("sched: fix cpu offlining with core scheduling")
Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
master commit: f294e3abe4
master date: 2026-07-21 09:47:36 +0200
AFL has pointed out that the op_bytes-is-not-0 assertion in common SIMD
handling can trigger for these insns. Indeed when the (relevant part of)
the controlling mask register is 0, no memory is accessed at all. Leave
op_bytes unaltered in this case, to engage the short-circuiting in common
SIMD handling when fault_suppression is true and op_bytes is 0.
While there also correct a related typo in the test harness.
Fixes: 65f82d4ce1 ("x86emul: support AVX512{F,_VBMI2} compress/expand insns")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: cf90c8a48a
master date: 2026-07-20 09:50:00 +0200
The APM description of the AltMovCR8 feature bit is:
"LOCK MOV CR0 means MOV CR8"
Adjust the decode logic to behave like this.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Teddy Astie <teddy.astie@vates.tech>
master commit: 7d48ef45b6
master date: 2026-07-10 19:35:49 +0100
Unmapping the virtual VMCB is performed near the end of the domain
destroy procedure but the mapped guest frame prevents domain destroy
from getting to that point. This means guests that call VMRUN cannot
be fully destroyed.
Move the unmap of the virtual VMCB earlier to fix the issue.
Fixes: bcf557675d ("x86: properly use map_domain_page() in nested HVM code")
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 4d069a84ee
master date: 2026-06-30 09:41:35 +0200
In order to use cpu_has_* expanding to host_cpu_policy.*, the host policy
needs setting up alongside boot_cpu_data.x86_capability[]. Arrange for
that towards the end of identify_cpu(). Then make sure .x86_capability[]
and host policy remain in sync when setup_{force,clear}_cpu_cap() are
used.
Rename the function now it's no longer static.
Fixes: 894bd76179 ("x86/Intel: use host CPU policy for ARAT checking")
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
When removing a CPU from a cpupool running the credit scheduler, a
race might happen between schedule_cpu_rm() and csched_timer(),
resulting in a NULL dereference.
The timer associated with csched_timer() is killed only in
csched_deinit_pdata(), which is called by schedule_cpu_rm() after
setting the scheduler's per-cpu data to NULL AND after enabling
interrupts again. This can result in the timer firing before being
killed, so csched_timer() needs to test the per-cpu data being set
before accessing it.
Fixes: 78be3dbbfe ("cpupools [1/6]: hypervisor changes")
Reported-by: Dietmar Hahn <dietmar.hahn@fujitsu.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
(cherry picked from commit ea1d785a5f)
Add the missing ARM logic, populating xen_arm_arch_domainconfig
from the raw xc_domaininfo_t the same way the x86 branch does for
xen_x86_arch_domainconfig.
Fixes: 9d683b5e37 ("tools/ocaml: Expose arch_config in domaininfo")
Fixes: 81838c9067 ("ocaml: fix arm build")
Signed-off-by: Julian Vetter <julian.vetter@vates.tech>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Teddy Astie <teddy.astie@vates.tech>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
(cherry picked from commit 01b4b39e2e)
The Store_field(result, 16, arch_config) sits inside an #ifdef x86, meaning
that on other architectures the pointer is not filled in. Ocaml code then
falls over a NULL(ish) pointer (really the Val_unit used to initialise
'result') when the layout in the heap doesn't match the type system.
Rearrange alloc_domaininfo() to avoid this. Similarly to
physinfo_arch_caps(), raise an exception if the architecture code hasn't
filled in an appropriate tag. Move the setup of arch_domainconfig to be
common logic.
In order to simplify the addition of other architectures, remove the
arch_config variable (reusing tmp as it's touched exactly once), and rename
x86_arch_config to be arch_config so each architecture can fill in a suitable
one without needing more local variables.
Fixes: 9d683b5e37 ("tools/ocaml: Expose arch_config in domaininfo")
Fixes: 81838c9067 ("ocaml: fix arm build")
Reported-by: Julian Vetter <julian.vetter@vates.tech>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Teddy Astie <teddy.astie@vates.tech>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
(cherry picked from commit 365d2a5be3)
XSA-443 and XSA-497 addressed specific issues in specific file system
drivers (libfsimage) used by pygrub. Further issues were reported, and yet
more are to be expected. XSA-443 introduced a means to run pygrub de-
privileged. Only this mode of operation is security supported from now on.
This is XSA-508.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
(cherry picked from commit 75f920bd47)
When doing PoD cache reclaim as part of a decrease reservation call, avoid
reclaiming special pages for the PoD cache. Otherwise such pages get moved
from the domain ->xenpage_list to the ->page_list, while still being
referenced in ->shared_info domain field.
Prevent PoD cache from reclaiming special pages, as nothing good can come
out of it.
This is XSA-507 / CVE-2026-62434.
Fixes: 41aa0b6269 ("PoD memory 4/9: Decrease reservation")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 372497ce42)
The hypercall requires at least one input buffer, as both arch-specific
implementations of dm_op() unconditionally assume ->buf[0] to be valid (and
not stack rubble).
Additionally, XEN_DMOP_modified_memory requires two input buffers, yet the
code was assuming the second buffer to always be provided by the user when
checking for the number of extents. In case the caller sets nr_bufs to 1,
the code in modified_memory() will read stack garbage as the size of the
buffer, thus allowing the caller some degree of insight on the contents of
the stack by probing whether the hypercall returns -EINVAL or -EFAULT as a
result of such bogus call.
This is XSA-506 / CVE-2026-62433.
Fixes: e3b93b3c59 ("dmop: add xendevicemodel_modified_memory_bulk()")
Fixes: 85cb15dfe4 ("x86/hvm/dmop: only copy what is needed to/from the guest")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit aef948a300)
evtchn_fifo_expand_array() will check for the domain evtchn_fifo being
populated without holding the event_lock, which can lead to a race with a
concurrent evtchn_reset().
Ensure the checking for evtchn_fifo presence is done while holding the
event_lock.
This is XSA-505 / CVE-2026-62432.
Fixes: 400b3bd642 ("evtchn: make EVTCHNOP_reset suitable for kexec")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit 0e9d647aca)
Otherwise in periodic mode a division by 0 would happen on the second call
to start_stimer() when using periodic mode.
Note that the HyperV specification states: "Writing the value zero to the
Count register will stop the counter, thereby disabling the timer,
independent of the setting of AutoEnable in the configuration register."
so a timer with a 0 count should never be in the enabled state.
This is XSA-504 / CVE-2026-62431.
Fixes: 26fba3c855 ("viridian: add implementation of synthetic timers")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit ff7d9aa77e)
Do the checking for a valid CMOS index while holding the spinlock,
otherwise the value could be changed by the guest after having been
checked.
This is XSA-503 / CVE-2026-62430.
Fixes: 34bef0e6d5 ("hvm: Add locking to platform timers.")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 52350da926)
Calling vnuma_destroy() without any locking can race the handling of both
XENMEM_get_vnumainfo and XEN_DOMCTL_setvnumainfo. While the latter is,
without Flask, strictly only exposed to the control domain, the former
can also be invoked by a stubdom DM or a de-privileged DM running in the
control domain. Isolate the logic used by XEN_DOMCTL_setvnumainfo into a
new helper function, which then is also used from domain_kill(). While
doing so also move the vnuma_destroy() invocation out of the locked
region.
With d->vnuma properly cleared by domain_kill(), XENMEM_get_vnumainfo now
really only needs to check for the field being NULL. That check needs
repeating, though, after re-acquiring the lock.
This is CVE-2026-62429 / XSA-502.
Fixes: 9695014966 ("xen: vnuma topology and subop hypercalls")
Reported-by: Teddy Astie <teddy.astie@vates.tech>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
(cherry picked from commit 2afa6fea9d)
Dropping and re-acquiring the grant table lock for a particular operation
requires special care, as in the meantime the grant table version can
change.
During a v2 -> v1 change, status frames going away means that pre-
calculated status pointers go stale, referencing freed (and possibly
already re-used) memory. Record in-flight v2 operations, permitting the
version change only when there are none of them. Recalculate "status" in
the one place (map_grant_ref()'s error path) where it could be stale, but
confine this to reserved entries.
This is CVE-2026-62436.
Reported-by: Mark Esler <mark@hexproof.dev>
During a v1 -> v2 change, the number of shared table entries reduces,
meaning that previously validated grant references may now be out of
bounds. Because of the checking of pin counts in gnttab_set_version()
(with the grant table lock held for writing), for now-out-of-bounds gref-s
neither active mappings can exist, nor can there be in-progress copy
operations. Nevertheless bounds checks are added there, just to be on the
safe side.
For gnttab_transfer(), to cover the gap between the lock being dropped by
gnttab_prepare_for_transfer() and it being re-acquired, have the helper
return the version it found, and fail the operation if the version turns
out to have changed after re-acquiring the lock.
Further avoid needless use of shared_entry_header(), as it involves
pointer arithmetic which, when using an out-of-bounds ref, is UB.
This is CVE-2026-62435.
Everything together is XSA-501.
Fixes: a98dc13703 ("Introduce a grant_entry_v2 structure")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Mark Esler <mark@hexproof.dev>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit 96dfeb4177)
acquire_grant_for_copy() passes to its caller both an MFN and a struct
page_info *. The two really need to be in sync for the get_page()
underlying get_paged_frame() and get_page_type() (both acting on the
passed back struct page_info *) and the map_domain_page() (acting on the
passed back MFN) to achieve the intended effect.
Go further and also check other properties: GTF_transitive / GTF_sub_page
may have been flipped in the shared entry, so respective fields / values
also may not match.
The one field which we can be sure does match (as it was checked earlier
in the function) is ->domid. Add an assertion nevertheless.
This is CVE-2026-62428 / XSA-500.
Fixes: d8cbecb1ee ("grant-tables: Use get_page_from_gfn() instead of get_gfn()/put_gfn")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
(cherry picked from commit 61b0a59ce2)
Integrate the checking with xsm_sysctl(), now that it has the full op
struct passed. As a positive side effect, permissions are then checked at
the same early point with and without Flask.
This is part of CVE-2026-62426 / XSA-499.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-By: Daniel P. Smith <dpsmith@apertussolutions.com>
(cherry picked from commit 299de2aeda)
Integrate the checking with xsm_sysctl(), now that it has the full op
struct passed. As a positive side effect, permissions are then checked at
the same early point with and without Flask. Note that these were x86-
only, i.e. some dead/unreachable code gets eliminated for (in particular)
Arm.
This is part of CVE-2026-62426 / XSA-499.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-By: Daniel P. Smith <dpsmith@apertussolutions.com>
(cherry picked from commit 0501e1dc04)
Integrate the checking with xsm_sysctl(), now that it has the full op
struct passed. As a positive side effect, permissions are then checked at
the same early point with and without Flask.
This is part of CVE-2026-62426 / XSA-499.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-By: Daniel P. Smith <dpsmith@apertussolutions.com>
(cherry picked from commit 4b249cba4b)
To shield the sysctl lock from abuse by unauthorized domains, follow what
5154fdda11 ("domctl: protect locking for get_domain_state") did: Check
for permission to issue the operation against DOM_XEN in flask_sysctl().
The finer-grained xsm_getdomaininfo() later in the handling of the sub-op
remains unaltered.
In the in-tree policy respective permission therefore needs granting.
This is part of CVE-2026-62426 / XSA-499.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
(cherry picked from commit 3179bf2931)
Integrate the checking with xsm_sysctl(), now that it has the full op
struct passed. As a positive side effect, permissions are then checked at
the same early point with and without Flask.
This is part of CVE-2026-62426 / XSA-499.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-By: Daniel P. Smith <dpsmith@apertussolutions.com>
(cherry picked from commit 751e371c91)
Integrate the checking with flask_platform_op(); there never really was a
need to defer these checks, as the sub-op has always been known to the
function. As a positive side effect, permissions are then checked at the
same early point with and without Flask.
This is CVE-2026-62427 / part of XSA-499.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-By: Daniel P. Smith <dpsmith@apertussolutions.com>
(cherry picked from commit 4ef45cbe31)
Mykola Kvach