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commit 5ec42d57655c690234c14aece6dd3f209778c1d8 upstream.
Explicitly clear role.invalid when deriving a child shadow page's role from
its parent to harden against bugs elsewhere in KVM, as violating KVM's
invariant that invalid pages are NOT on the list of active MMU pages leads
to use-after-free due to __kvm_mmu_prepare_zap_page() using list_add()
instead of list_move() when processing an invalid shadow page, i.e. makes a
bad situation far worse.
Yell loudly if the parent is invalid, as it means KVM has missed a validity
check, i.e. KVM is attempting to map memory using an invalid/obsolete root,
but continue on as the child is otherwise still a valid shadow page.
==================================================================
BUG: KASAN: slab-use-after-free in __kvm_mmu_get_shadow_page+0x1817/0x1860 [kvm]
Write of size 8 at addr ff11000153dd1368 by task repro/853
CPU: 1 UID: 1000 PID: 853 Comm: repro Not tainted 7.2.0-rc2-3aec122bdcaf-next-vm #5 PREEMPT
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Call Trace:
<TASK>
dump_stack_lvl+0x4b/0x70
print_report+0x153/0x49c
kasan_report+0xbc/0xf0
__kvm_mmu_get_shadow_page+0x1817/0x1860 [kvm]
mmu_alloc_root+0x141/0x320 [kvm]
kvm_mmu_load+0x612/0x20f0 [kvm]
kvm_arch_vcpu_ioctl_run+0x3dd5/0x6150 [kvm]
kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm]
__x64_sys_ioctl+0x131/0x1b0
do_syscall_64+0x67/0x5f0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK>
Allocated by task 853:
kasan_save_stack+0x20/0x40
kasan_save_track+0x14/0x30
__kasan_slab_alloc+0x5f/0x70
kmem_cache_alloc_noprof+0xfe/0x2e0
__kvm_mmu_topup_memory_cache+0x135/0x530 [kvm]
paging64_page_fault+0x318/0x1e30 [kvm]
kvm_mmu_do_page_fault+0x21d/0x630 [kvm]
kvm_mmu_page_fault+0x18c/0x17b0 [kvm]
kvm_arch_vcpu_ioctl_run+0x1f35/0x6150 [kvm]
kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm]
__x64_sys_ioctl+0x131/0x1b0
do_syscall_64+0x67/0x5f0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Freed by task 853:
kasan_save_stack+0x20/0x40
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x43/0x70
kmem_cache_free+0xe2/0x400
kvm_mmu_commit_zap_page.part.0+0x1e2/0x310 [kvm]
kvm_mmu_free_roots+0x283/0x560 [kvm]
kvm_arch_vcpu_ioctl_run+0x33c8/0x6150 [kvm]
kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm]
__x64_sys_ioctl+0x131/0x1b0
do_syscall_64+0x67/0x5f0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Reported-by: Hyunwoo Kim <imv4bel@gmail.com>
Fixes: a770f6f28b1a ("KVM: MMU: Inherit a shadow page's guest level count from vcpu setup")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 0cfe660559e857d7c00ab86c73e4510ce069086f ]
The current implementation of aisb calculation will erroneously index
via an unsigned long * as well as multiply by 8B for every 64-bits in
the offset; only one or the other is required. This throws off aisb
calculations once the number of devices exceeds 64, and can result
in out-of-bounds access as well as failure to indicate summary bits
associated with those devices in guests.
Fix this by converting to a physical address before applying the
offset, as is already done in arch/s390/pci/pci_irq.c.
Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding")
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
[alifm@linux.ibm.com: Resolved merge conflict]
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 5580c9858f1e00f60191eb09c3add359836d60b6 ]
Currently if kvm_zpci_set_airq() fails, kvm_s390_pci_aif_enable() returns
the error code but doesn't do any resource cleanup thus leaking resources.
Fix this by cleaning up all the resources such as the GAITE, AIBV, AISB and
unpinning any pinned pages. While at it, remove dead code that stored FIB
values that were never referenced.
As part of the cleanup, we are also holding the aift_lock a bit longer, as
we hold the lock while executing the MPCIFC instruction. Though this is not
strictly necessary, it means we don't have to drop and re-acquire in the
error case.
Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding")
Cc: stable@vger.kernel.org
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
[alifm@linux.ibm.com: Resolved merge conflict]
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit f86842e4d6c482300f4567f492d512c9ccf5bc4f ]
In kvm_s390_pci_aif_enable() two error paths failed to set an error code,
causing the function to return 0 on failure. It also failed to rollback
memory accounting on failure. Fix both by propagating an error code on
failure and calling unaccount_mem() in the cleanup path.
Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding")
Cc: stable@vger.kernel.org
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
[alifm@linux.ibm.com: Resolve merge conflict]
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 36f6999ecde3976731a8bfc0b8e667da6f593069 ]
The account_mem() and unaccount_mem() functions call get_uid() which
increments the reference count of struct user_struct on every invocation.
But we don't decrement the count by calling free_uid(). It also
accounted/unaccounted the pages against the current->mm. But its possible
the unaccount_mem() can be called from a different process context than the
one that originally pinned the pages.
Let's fix this by storing the pinning process user_struct and mm_struct
when accounting for pinned pages, and subsequently free these resources
when the pages are unpinned.
Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding")
Cc: stable@vger.kernel.org
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
[borntraeger@linux.ibm.com: Fixed whitespace]
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
[alifm@linux.ibm.com: Resolve merge conflict]
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit bab4d538f8485e0d48538fcb82b285df3779278e ]
PCIe controller 2 has interrupts 0-4 mapping to GIC SPI 138-142. The
mapping for interrupt 1 was incorrectly set to 138 due to a copy-paste
error. Fix it to 139.
Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://lore.kernel.org/r/20260725215722.9323-1-rosenp@gmail.com
Fixes: 3b3e35b279be ("ARM: dts: BCM5301X: Relicense AXI interrupts code to the GPL 2.0+ / MIT")
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 8eb052f48331474c2789d07b7f11165c323bd2f9 ]
npcm7xx_smp_boot_secondary() and npcm7xx_smp_prepare_cpus() look up
the GCR and SCU nodes with of_find_compatible_node(). The returned
nodes are used for of_iomap(), but the node references are never
released.
of_iomap() does not consume the device node reference, and iounmap()
only releases the MMIO mapping. Drop each node reference after the
corresponding mapping attempt.
Fixes: 7bffa14c9aed ("arm: npcm: add basic support for Nuvoton BMCs")
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
Reviewed-by: Avi Fishman <avifishman70@gmail.com>
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit af421e9aed3920c7ac88c24daa48606c7112feca upstream.
When vector_mmsg_rx() discards a packet whose overlay header fails
verify_header(), it frees the skb and continues the loop:
if (header_check < 0) {
dev_kfree_skb_irq(skb);
vp->estats.rx_encaps_errors++;
continue;
}
The normal and short-packet paths fall through to the bottom of the
loop body, which clears the consumed slot and advances the cursors:
(*skbuff_vector) = NULL;
mmsg_vector++;
skbuff_vector++;
The verify_header() < 0 path skips that via continue, so the freed skb
is left in skbuff_vector[] and the cursors do not advance. The next
iteration reads the same slot, gets the freed skb, and frees it again,
producing a refcount underflow / use-after-free in the RX path.
Discard the slot the same way the other paths do before continuing.
Only transports whose verify_header() can return negative are affected:
GRE and L2TPv3 do so on a cookie/session-id mismatch (raw/tap do not),
so any peer on such a transport can trigger it without authentication.
Fixes: 49da7e64f33e ("High Performance UML Vector Network Driver")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 0bb024f11d120abff3e8db9144a585b9d7fb8459 upstream.
If lv1_put_iopte() fails in dma_ioc0_map_pages(), the error path
decrements iopage but keeps using the failed mapping's offset. As a
result, it repeatedly tries to invalidate the failed IOPTE slot and
leaves the already installed IOPTEs valid.
Recompute offset and invalidate the installed IOPTEs instead.
Fixes: 6bb5cf102541 ("[POWERPC] PS3: System-bus rework")
Cc: stable@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260711130931.740719-3-thorsten.blum@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 868d32ac72cba21c5c6d8a66a814b7c25a3a5c01 upstream.
The AIBV holds one bit per MSI-X vector for a given function. The size of
the bit vector is derived from the NOI and the AIBVO. If the size of the
AIBV exceeds a single page boundary, then reject the request as we cannot
safely pin the guest AIBV.
Similarly reject the request if the AISB address is not 8-byte aligned as
the architecture requires doubleword alignment for the summary bit address.
Since the AISBO can address up to 64 bits, the size of the AISB can only be
8 bytes for the function. This also ensures the AISB doesn't exceed a
single page boundary.
Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding")
Cc: stable@vger.kernel.org
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 8bf09b9b7d3232806df95f409581f8a9fd99a3fa upstream.
The airq_iv_create() can return NULL on failure, but the return value was
never checked. If it fails, zdev->aibv will be NULL and fail when
dereferenced in kvm_zpci_set_airq(). Add a NULL check and free the
previously allocated AISB bit and zdev->aisb on failure.
Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding")
Cc: stable@vger.kernel.org
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 8fa01be5a6149404adb82c0979a78f6347edd3ef upstream.
The MPCIFC instruction doesn't allow registering adapter interrupts without
first unregistering. So reject any request to enable interrupt forwarding
if its already enabled for the zPCI device. This also fixes overwriting and
thus leaking resources when the ioctl is called multiple times for the same
device.
Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding")
Cc: stable@vger.kernel.org
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 7d3aae206663c4e006b25a1c7a20a4029e67da76 upstream.
Always update x2APIC MSR intercepts for L1 when AVIC is deactivated, even
if L2 is active and KVM is using a separate MSR bitmap to run L2. If AVIC
is fully enabled prior to running L2, and is then inhibited while L2 is
active (for a VM-scoped inhibit), then KVM will run L1 with AVIC disabled,
but with x2APIC MSR intercepts disabled, i.e. will allow L1 to read most of
the host's APIC state, send arbitrary interrupts, change task priority, and
ultimately trivially DoS the host.
E.g. sending a self-IPI in L1 on HYPERV_REENLIGHTENMENT_VECTOR, 0xee, with
CONFIG_HYPERV=n in the host kernel as a "safe" PoC, yields:
Spurious interrupt (vector 0xee) on CPU#425. Acked
And hacking KVM to abuse kvm_set_posted_intr_wakeup_handler() to register a
handler and WARN on POSTED_INTR_WAKEUP_VECTOR yields:
------------[ cut here ]------------
WARNING: arch/x86/kvm/svm/svm.c:5594 at pi_wakeup_handler+0x9/0x10 [kvm_amd], CPU#156: nested_x2apic_t/316940
CPU: 156 UID: 0 PID: 316940 Comm: nested_x2apic_t Tainted: G S U
Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER
Hardware name: Google Astoria-Turin/astoria, BIOS 0.20260209.0-0 02/09/2026
RIP: 0010:pi_wakeup_handler+0x9/0x10 [kvm_amd]
Call Trace:
<IRQ>
sysvec_kvm_posted_intr_wakeup_ipi+0x64/0x80
</IRQ>
<TASK>
asm_sysvec_kvm_posted_intr_wakeup_ipi+0x1a/0x20
RIP: 0010:vcpu_run+0x1430/0x1e40 [kvm]
kvm_arch_vcpu_ioctl_run+0x2c1/0x600 [kvm]
kvm_vcpu_ioctl+0x580/0x6b0 [kvm]
__se_sys_ioctl+0x6d/0xb0
do_syscall_64+0x10a/0x480
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x46ff4b
</TASK>
---[ end trace 0000000000000000 ]---
Fixes: 091abbf578f9 ("KVM: x86: nSVM: optimize svm_set_x2apic_msr_interception")
Cc: stable@vger.kernel.org
Cc: Yosry Ahmed <yosry@kernel.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://patch.msgid.link/20260729213558.639074-1-pbonzini@redhat.com/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit b24fc8278b70a9d27ec801a427ab4de9b769d69a ]
fdt_node_offset_by_prop_value() returns a negative error code on
failure - fix the check accordingly.
Fixes: 2a2c74b2efcb ("IBM Akebono: Add the Akebono platform")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260702211554.56923-6-thorsten.blum@linux.dev
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 43863f6575d2211e8c5157fefb83ad0ad046aab4 ]
fdt_node_offset_by_prop_value() returns a negative error code on
failure - fix the check accordingly.
Fixes: 228d55053397 ("powerpc/47x: Add support for the new IBM currituck platform")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260702211554.56923-5-thorsten.blum@linux.dev
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit c824ab65685bb119c6c6a3a200b3428c72862d5a ]
fdt_node_offset_by_prop_value() returns a negative error code on
failure - fix the check accordingly.
Fixes: d2477b5cc8ca ("[POWERPC] bootwrapper: Add a firmware-independent simpleboot target.")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260702211554.56923-4-thorsten.blum@linux.dev
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 7e7f81cf6f5ca3311e526308f55d7c54d3ba71f9 upstream.
An attacker injecting interrupts while the Safe-RET mitigation executes
on machines affected by SRSO can neutralize the safe return sequence,
potentially leading to data leakage through speculative execution.
Fixup register state as if the Safe-RET sequence executed successfully
by "emulating" it, in a manner of speaking, and avoid executing a RET
instruction after returning from the interrupt.
Co-developed-by: David Kaplan <David.Kaplan@amd.com>
Signed-off-by: David Kaplan <David.Kaplan@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This reverts commit 608c8f5dccaaf8b8d2b28c0fbdd439d144be62b0 which is
commit 7e7f81cf6f5ca3311e526308f55d7c54d3ba71f9 upstream.
It was incorrect, a more correct fix will be applied next.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 7e7f81cf6f5ca3311e526308f55d7c54d3ba71f9 upstream.
An attacker injecting interrupts while the Safe-RET mitigation executes
on machines affected by SRSO can neutralize the safe return sequence,
potentially leading to data leakage through speculative execution.
Fixup register state as if the Safe-RET sequence executed successfully
by "emulating" it, in a manner of speaking, and avoid executing a RET
instruction after returning from the interrupt.
Co-developed-by: David Kaplan <David.Kaplan@amd.com>
Signed-off-by: David Kaplan <David.Kaplan@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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hotplug
commit 25f744ffa0c8e799e06250ce2e618367b166b0d4 upstream.
If a vCPU stays scheduled out (or blocked) while the last pCPU it ran
on goes through a hotplug cycle (online->offline->online), and the vCPU
then resumes execution on the same pCPU, then it is possible for it to
run with an ASID that has now been assigned to a different vCPU,
resulting in stale TLB translations being used.
svm_enable_virtualization_cpu() resets asid_generation to 1 and sets
next_asid to max_asid + 1 on every CPU online event, including hotplug
cycles. Because next_asid starts beyond the pool boundary, the first
call to new_asid() after an online event always wraps the pool,
incrementing asid_generation to 2 and assigning ASIDs starting from
min_asid.
Consider two vCPUs from different VMs, vCPU-A pinned to CPU-X holding
asid_generation=2 and ASID=N from before the hotplug event:
1. CPU-X goes offline and back online: asid_generation resets to 1,
next_asid = max_asid + 1.
2. One or more vCPUs migrate to CPU-X and call new_asid(), wrapping
the pool and consuming ASIDs starting from min_asid. Eventually
vCPU-B from a different VM is assigned asid_generation=2, ASID=N
— the same ASID that vCPU-A held before the hotplug.
3. vCPU-A enters pre_svm_run() on CPU-X: current_vmcb->cpu is
unchanged so the migration branch is skipped. Its saved
asid_generation=2 matches sd->asid_generation=2, so the generation
check silently passes and vCPU-A continues running with ASID=N —
the same ASID just freshly assigned to vCPU-B.
Both vCPUs from different VMs now run on CPU-X with the same ASID,
causing them to share NPT TLB entries and producing stale translations.
The collision manifests as a KVM internal error (Suberror: 1, emulation
failure). The NPT page fault reports a faulting GPA far outside the
VM's physical memory range — a sign of stale TLB translations being
used. KVM falls back to instruction emulation, which fails on
FPU/XSave instructions (XRSTOR, STMXCSR) that the emulator does not
implement.
Fix this by incrementing asid_generation instead of resetting it to 1
in svm_enable_virtualization_cpu(). On module load, asid_generation
starts at 0 (memset) and the increment produces 1, identical to the
old behaviour. On subsequent hotplug cycles the generation advances
beyond any value a vCPU previously observed on this CPU, so the
generation check in pre_svm_run() reliably forces new_asid() on every
vCPU after every hotplug cycle.
Fixes: 774c47f1d78e ("[PATCH] KVM: cpu hotplug support")
Reported-by: Chandrakanth Silveru <Chandrakanth.Silveru@amd.com>
Tested-by: Srikanth Aithal <Srikanth.Aithal@amd.com>
Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
Message-ID: <20260715063506.672432-1-nikunj@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit e800decd9c0ac4349bcd8f8f9b29fd21fe93165e ]
On Intel platforms with a VMX preemption timer and APICv, if a VMM
calls KVM_GET_LAPIC before KVM_GET_MSRS to save the vCPU state, it is
possible to lose a pending timer interrupt.
If the thread running these ioctls is migrated to another core after
calling KVM_GET_LAPIC but before KVM_GET_MSRS and the guest is using
their LAPIC timer in TSC-deadline mode, not only does the save LAPIC
state not carry the pending interrupt, the TSCDEADLINE MSR will be
zeroed.
After migration across CPUs, KVM_GET_MSRS calls vcpu_load, posting the
interrupt and clearing the MSR:
vcpu_load() ->
kvm_arch_vcpu_load() ->
kvm_lapic_restart_hv_timer() ->
start_hv_timer() ->
apic_timer_expired() ->
kvm_apic_inject_pending_timer_irqs()
. post interrupt into the LAPIC state
. clear IA32_TSCDEADLINE
The saved LAPIC state will be missing the pending interrupt and the saved
MSR will be zero. Oops.
Fix by only posting an interrupt when we're attempting to enter the guest
(vcpu->wants_to_run == true), not for vcpu_load from other paths.
Assisted-by: gemini:gemini-3.1-pro-preview
Debugged-by: David Matlack <dmatlack@google.com>
Debugged-by: Sean Christopherson <seanjc@google.com>
Debugged-by: Jim Mattson <jmattson@google.com>
Debugged-by: James Houghton <jthoughton@google.com>
Signed-off-by: Venkatesh Srinivas <venkateshs@chromium.org>
Message-ID: <20260715234234.15382-2-venkateshs@chromium.org>
Reviewed-by: James Houghton <jthoughton@google.com>
Reviewed-by: Chao Gao <chao.gao@intel.com>
Cc: stable@vger.kernel.org
Fixes: ae95f566b3d2 ("KVM: X86: TSCDEADLINE MSR emulation fastpath", 2020-05-15)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit a6816314af5749cd88944bfdceb270c627cdf348 ]
Introduce vcpu->wants_to_run to indicate when a vCPU is in its core run
loop, i.e. when the vCPU is running the KVM_RUN ioctl and immediate_exit
was not set.
Replace all references to vcpu->run->immediate_exit with
!vcpu->wants_to_run to avoid TOCTOU races with userspace. For example, a
malicious userspace could invoked KVM_RUN with immediate_exit=true and
then after KVM reads it to set wants_to_run=false, flip it to false.
This would result in the vCPU running in KVM_RUN with
wants_to_run=false. This wouldn't cause any real bugs today but is a
dangerous landmine.
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20240503181734.1467938-2-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Stable-dep-of: e800decd9c0a ("KVM: x86: Only reset TSC Deadline Timer in apic_timer_expired on KVM_RUN")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit b9f089723aee892efc77c349ae47a6b452b293c4 ]
A pseudo-locked group's RMID is freed when it is created. On unmount
rmdir_all_sub() unconditionally frees all RMID of all groups, resulting
in a double-free of the pseudo-locked group's RMID. The consequence of this
is that the original free results in the pseudo-locked group's RMID being
added to the rmid_free_lru linked list and the second free then attempts
to add the same RMID entry to the rmid_free_lru again.
Do not double-free a pseudo-locked group's RMID.
Fixes: e0bdfe8e36f3 ("x86/intel_rdt: Support creation/removal of pseudo-locked region")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/551432dd7e624a862b8e58314c38aaba0afff3e9.1783377598.git.reinette.chatre@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 26b483d52417253d88a3a01262ac85914a7aec8e upstream.
This reverts commit e057b94772328221405b067c3a85fe479b915dc8.
Sashiko points out that updating 'orig_x0' after secure_computing()
has returned is too late to handle the case where a seccomp filter is
re-evaluated after initially returning SECCOMP_RET_TRACE. This means
that a tracer can manipulate the first argument of the syscall behind
seccomp's back.
For now, revert the initial fix and we'll have another crack at it soon.
Since the incorrect fix was cc'd to stable, do the same here with an
appropriate fixes tag.
Cc: stable@vger.kernel.org
Fixes: e057b9477232 ("arm64: syscall: Ensure saved x0 is kept in-sync with tracer updates")
Link: https://sashiko.dev/#/patchset/20260716120640.6590-1-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e057b94772328221405b067c3a85fe479b915dc8 upstream.
When seccomp support was originally added to arm64 in a1ae65b21941
("arm64: add seccomp support"), seccomp was erroneously called _before_
the ptrace syscall-enter-stop and therefore the tracer could trivially
manipulate the syscall register state after the seccomp check had
passed. This was subsequently fixed in a5cd110cb836 ("arm64/ptrace: run
seccomp after ptrace") by moving the seccomp check after the tracer has
run. Unfortunately, a decade later, that fix has been reported to be
incomplete.
On arm64, both the first argument to a syscall and its eventual return
value are allocated to register x0. In order to facilitate syscall
restarting and querying of syscall arguments on the syscall exit path,
the original value of x0 is stashed in 'struct pt_regs::orig_x0' early
during the syscall entry path and is returned for the first argument by
syscall_get_arguments(). Unlike 32-bit Arm, this stashed value is not
directly exposed via ptrace() and so changes to register x0 made by the
tracer on a syscall-enter-stop are not reflected in 'orig_x0'. This
means that seccomp, syscall tracepoints and audit can observe a stale
value for the register compared to the argument that will be observed by
the actual syscall.
Re-sync 'orig_x0' from x0 on the syscall entry path following a
potential ptrace stop (i.e. PTRACE_EVENTMSG_SYSCALL_ENTRY or
SECCOMP_RET_TRACE). This behaviour is limited to native tasks (because
compat tasks expose 'orig_r0' to ptrace) where the syscall is not being
skipped (because x0 is updated to hold the return value of -ENOSYS in
that case).
Cc: Kees Cook <kees@kernel.org>
Cc: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Reported-by: Yiqi Sun <sunyiqixm@gmail.com>
Link: https://lore.kernel.org/all/20260529065444.1336608-1-sunyiqixm@gmail.com/
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Fixes: a5cd110cb836 ("arm64/ptrace: run seccomp after ptrace")
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Tested-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 4a9ec5ec9555ad62dc5b81a37ac946025c2ea002 upstream.
After a recent upstream LLVM change to start generating jump and lookup
tables in switch statements in more instances [1], linking the
compressed x86 boot image when CONFIG_KERNEL_ZSTD is enabled fails with:
ld.lld: error: Unexpected run-time relocations (.rela) detected!
Dumping the relocations in misc.o, which is the only file influenced by
CONFIG_KERNEL_ZSTD in the decompressor, shows dynamic relocations to
some string constants, which correspond to the string literals in the
switch statement in handle_zstd_error():
Relocation section '.rela.data.rel.ro' at offset 0x277b0 contains 31 entries:
Offset Info Type Symbol's Value Symbol's Name + Addend
0000000000000000 0000006600000001 R_X86_64_64 0000000000000000 .rodata.str1.1 + 73a
0000000000000008 0000006600000001 R_X86_64_64 0000000000000000 .rodata.str1.1 + 78e
0000000000000010 0000006600000001 R_X86_64_64 0000000000000000 .rodata.str1.1 + 78e
0000000000000018 0000006600000001 R_X86_64_64 0000000000000000 .rodata.str1.1 + 78e
...
This optimization is problematic for the decompressor environment, as it
is built as -fPIE without any explicit absolute references (as described
at the top of misc.c) while not applying any dynamic relocations, hence
the linker assertion. To opt out of this optimization, which is of
little value in this special early boot code, and to mirror the other
x86 startup code in arch/x86/boot/startup, disable jump tables in the
decompressor.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://github.com/llvm/llvm-project/commit/fa02a6ed66b1700c996b49c96c6bc0eb014c9518 [1]
Link: https://patch.msgid.link/20260722-x86-boot-compressed-disable-jt-clang-v2-1-7373d38482fb@kernel.org
Closes: https://github.com/ClangBuiltLinux/linux/issues/2165
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 73555fdab5e1e4f24ca000c41a616b34edf4b55d upstream.
When entering KDB via a breakpoint and then performing single-step
debugging, an oops is triggered. Now during single-step debugging,
kdb_local() expects the reason to be KDB_REASON_SSTEP, but it is
actually KDB_REASON_OOPS. In kdb_stub(), when determining the reason,
the ex_vector for single-step should be 0, as already implemented on
other architectures such as arm64 and riscv.
Before the patch:
[112]kdb> ss
Entering kdb (current=0x900020009f520000, pid 10661) on
processor 112 Oops: (null)
due to oops @ 0x90000000005b57a4
Cc: stable@vger.kernel.org
Signed-off-by: Haoran Jiang <jianghaoran@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit d024a0a7879e6f37c0152aacf6d8e37b214a1738 upstream.
KVM RISC-V tracks guest local interrupt state with two bitmaps:
- irqs_pending: interrupts that should be visible to the guest
- irqs_pending_mask: interrupts whose pending state changed
The current code updates those bitmaps with independent atomic bitops
and assumes a multiple-producer, single-consumer protocol. That model
does not actually hold.
kvm_riscv_vcpu_sync_interrupts() is not a pure consumer. When the guest
changes guest-visible HVIP state, sync_interrupts() writes both
irqs_pending and irqs_pending_mask to reflect the new guest state back
into KVM state. As a result, irqs_pending and irqs_pending_mask form a
single logical state transition, but they are not updated atomically as
a pair.
This allows a race where a newly injected interrupt is lost. For
example:
CPU0 CPU1
---- ----
kvm_riscv_vcpu_set_interrupt(VS_SOFT)
set_bit(VS_SOFT, irqs_pending)
kvm_riscv_vcpu_sync_interrupts()
sees guest-cleared HVIP.VSSIP
sets irqs_pending_mask
clear_bit(IRQ_VS_SOFT, irqs_pending)
set_bit(VS_SOFT, irqs_pending_mask)
kvm_vcpu_kick()
After that interleaving, a later flush can update HVIP without VSSIP
even though a new virtual interrupt was injected. In practice, the
guest can remain blocked in WFI with work pending.
The same pending/mask protocol is shared by VS soft interrupts, PMU
overflow delivery, and AIA high interrupt synchronization, so the race
is not limited to one interrupt source.
Fix this by serializing all updates to irqs_pending and irqs_pending_mask
with a per-vCPU raw spinlock. This keeps the pending bit and the dirty
mask as one state transition across:
- set/unset interrupt
- guest HVIP sync
- interrupt flush to guest CSR state
- vCPU reset
- AIA CSR writes that clear dirty state
Use non-atomic bitmap operations while holding the lock. Hold the lock
across the AIA sync, flush, and pending checks as well, so both bitmap
words share the same serialization domain.
This intentionally replaces the existing lockless protocol instead of
trying to repair it with additional barriers. The problem is not memory
ordering on a single field; it is that two separate bitmaps encode one
shared state machine while both producers and sync paths can modify
them. A per-vCPU raw spinlock keeps the fix small, local, and suitable
for backporting.
Fixes: cce69aff689e ("RISC-V: KVM: Implement VCPU interrupts and requests handling")
Cc: stable@vger.kernel.org
Signed-off-by: Xie Bo <xb@ultrarisc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260715020359.1521354-2-xb@ultrarisc.com
Signed-off-by: Anup Patel <anup@brainfault.org>
[ bo: Drop IRQ_PMU_OVF handling, which is not present in 6.6.y, and
adapt the reset and CSR helpers to their older signatures. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit c1c1ffa490fc33591e90852ed0d38804dd20bc36 ]
It was observed that /proc/stat had very large value for one ore more
CPUs. It was more visible after recent code simplifications around
cpustats.
System has 240 CPUs.
cat /proc/uptime;
194.18 46500.55
cat /proc/stat
cpu 5966 39 837032887 4650070 164 185 100 0 0 0
cpu0 108 0 837030890 19109 24 4 23 0 0 0
Since uptime is 194s, system time of each CPU can't be more than 19400.
Sum of system time of all CPUs can't be more than 19400*240 4656000.
In fact huge value is close to mftb(). Note mftb doesn't reset on powerVM
when the LPAR restart. It only resets when whole system resets. The same
issue exists for kexec too.
This happens since starttime is not setup at init time. Once it is set
then subsequent vtime_delta will return the right delta.
Fix it by initializing the starttime during CPU initialization. This
fixes the large times seen.
cat /proc/uptime; cat /proc/stat
15.78 3694.63
cpu 6035 35 1347 369479 23 144 49 0 0 0
cpu0 19 0 38 1508 0 1 14 0 0 0
Now, system time is reported as expected.
Fixes: cf9efce0ce31 ("powerpc: Account time using timebase rather than PURR")
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Suggested-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260605124329.377533-1-sshegde@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit c8ba971cf8567d49eb5f43ee90c4e50424331c18 ]
Currently the tick subsystem stores the idle cputime accounting in
private fields, allowing cohabitation with architecture idle vtime
accounting. The former is fetched on online CPUs, the latter on offline
CPUs.
For consolidation purpose, architecture vtime accounting will continue
to account the cputime but will make a break when the idle tick is
stopped. The dyntick cputime accounting will then be relayed by the tick
subsystem so that the idle cputime is still seen advancing coherently
even when the tick isn't there to flush the idle vtime.
Prepare for that and introduce three new APIs which will be used in
subsequent patches:
- vtime_dynticks_start() is deemed to be called when idle enters in
dyntick mode. The idle cputime that elapsed so far is accumulated.
- vtime_dynticks_stop() is deemed to be called when idle exits from
dyntick mode. The vtime entry clocks are fast-forward to current time
so that idle accounting restarts elapsing from now.
- vtime_reset() is deemed to be called from dynticks idle IRQ entry to
fast-forward the clock to current time so that the IRQ time is still
accounted by vtime while nohz cputime is paused.
Also accumulated vtime won't be flushed from dyntick-idle ticks to avoid
accounting twice the idle cputime, along with nohz accounting.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-6-frederic@kernel.org
Stable-dep-of: c1c1ffa490fc ("powerpc/vtime: Initialize starttime at boot for native accounting")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 89d6910cc562ab34d1f1c08f3cf0a9700b8bf2c4 ]
The generic vtime_task_switch() implementation gets built only
if __ARCH_HAS_VTIME_TASK_SWITCH is not defined, but requires an
architecture to implement arch_vtime_task_switch() callback at
the same time, which is confusing.
Further, arch_vtime_task_switch() is implemented for 32-bit PowerPC
architecture only and vtime_task_switch() generic variant is rather
superfluous.
Simplify the whole vtime_task_switch() wiring by moving the existing
generic implementation to PowerPC.
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2cb6e3caada93623f6d4f78ad938ac6cd0e2fda8.1712760275.git.agordeev@linux.ibm.com
Stable-dep-of: c1c1ffa490fc ("powerpc/vtime: Initialize starttime at boot for native accounting")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 0dfa1e960f86e032007882b032c5cc7d14ebe73e ]
The Tegra234 SoC uses Cortex-A78AE cores, not Cortex-A78. Update the
compatible string for all CPU nodes to match the actual hardware.
Tegra234 hardware reports:
# head /proc/cpuinfo | egrep 'implementer|part'
CPU implementer : 0x41
CPU part : 0xd42
Which maps to (from arch/arm64/include/asm/cputype.h):
#define ARM_CPU_IMP_ARM 0x41
#define ARM_CPU_PART_CORTEX_A78AE 0xD42
Fixes: a12cf5c339b08 ("arm64: tegra: Describe Tegra234 CPU hierarchy")
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 52f2f7c30126037975389aa04d24c506a5177c35 upstream.
mmu_destroy_caches() destroys pte_list_desc_cache and
mmu_page_header_cache, but leaves both pointers unchanged. The pointers
live in kvm.ko, and therefore survive when a vendor module is unloaded
while kvm.ko remains loaded.
If creation of pte_list_desc_cache fails during a subsequent vendor
module load, its assignment sets pte_list_desc_cache to NULL and the
error path calls mmu_destroy_caches(). mmu_page_header_cache still
points to the cache destroyed during the preceding vendor module
unload. Passing that stale pointer to kmem_cache_destroy() causes a
slab use-after-free.
Reproduce the issue on a v7.1.3 kernel with CONFIG_KASAN=y,
CONFIG_KASAN_GENERIC=y, CONFIG_KVM=m, and CONFIG_KVM_INTEL=m. A
one-shot test hook forces pte_list_desc_cache to NULL on the second
invocation of kvm_mmu_vendor_module_init():
1. Load kvm.ko and kvm-intel.ko, creating both caches.
2. Unload only kvm_intel, leaving kvm.ko loaded.
3. Reload kvm_intel and force initialization through the -ENOMEM path.
KASAN reports:
BUG: KASAN: slab-use-after-free in
kvm_mmu_vendor_module_init+0x5b/0x170 [kvm]
...
kmem_cache_destroy+0x21/0x1d0
kvm_mmu_vendor_module_init+0x5b/0x170 [kvm]
...
Allocated by task 16817:
__kmem_cache_create_args+0x12c/0x3b0
__kmem_cache_create.constprop.0+0xb6/0xf0 [kvm]
kvm_mmu_vendor_module_init+0x13b/0x170 [kvm]
...
Freed by task 16820:
kmem_cache_destroy+0x117/0x1d0
kvm_mmu_vendor_module_exit+0x21/0x30 [kvm]
Clear both pointers immediately after destroying their caches so that
the stored state reflects the caches' lifetime and repeated cleanup is
safe.
With the fix applied, the same injected vendor module reload fails with
-ENOMEM as expected and produces no KASAN report.
Fixes: cb498ea2ce1d ("KVM: Portability: Combine kvm_init and kvm_init_x86")
Cc: stable@vger.kernel.org
Signed-off-by: Phil Rosenthal <phil@phil.gs>
Message-ID: <20260718-kvm-mmu-cache-uaf-v3-1-e103b93c74e1@phil.gs>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 622ebfac01ba4f9c0060cebd41257fe46fc4a0b3 upstream.
free_nested() frees the shadow VMCS while vmcs01 still points to it. But
because it is asynchronous with respect to loaded_vmcs_clear(), the vCPU
might migrate before the pointer is cleared and __loaded_vmcs_clear()
may then execute VMCLEAR.
The VMCS needs to stay attached until its explicit VMCLEAR completes, but
then it can be hidden and the page safely freed.
Fixes: 355f4fb1405e ("kvm: nVMX: VMCLEAR an active shadow VMCS after last use")
Cc: stable@vger.kernel.org
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 2abd5287f08319fa35764566b15c6e22cb1068db upstream.
Check for a "stale" page fault, i.e. for an invalid and/or obsolete root,
after making MMU pages available for the shadow MMU. If reclaiming shadow
pages zaps an in-use root, i.e. marks it invalid, then KVM will attempt to
map memory into an invalid root. On its own, populating an invalid root is
"fine", but because child shadow pages inherit their parent's role, any
children created during the map/fetch will be created as invalid pages,
thus violating KVM's invariant that invalid pages are never on the list of
active MMU pages.
Note, the underlying flaw has existed since KVM first started tracking
invalid roots in 2008 (commit 2e53d63acba7, "KVM: MMU: ignore zapped root
pagetables"), but the true badness only came along in 2020 (Linux 5.9)
with the invariant that invalid shadow pages can't be on the list of
active pages.
Note #2, inheriting role.invalid when creating child shadow pages is also
far from ideal; that flaw will be addressed separately.
Reported-by: Hyunwoo Kim <imv4bel@gmail.com>
Fixes: f95eec9bed76 ("KVM: x86/mmu: Don't put invalid SPs back on the list of active pages")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 3a07249981629ace483ebbef81ef6b34c2d2afec upstream.
kvm_io_bus_get_dev() returns a device that is only matched by the
address, and nothing else. This can cause a lifetime issue if
the matched device is not the expected type, as by the time
the caller can introspect the object, it might be gone (the srcu
lock having been dropped).
Given that there is only a single user of this helper, the simplest
option is to move the locking responsibility to the caller, which
can keep the srcu lock held for as long as it wants.
Note that this aligns with other kvm_io_bus*() helpers, which
already require the srcu lock to be held by the callers.
Reported-by: Will Deacon <will@kernel.org>
Fixes: 8a39d00670f07 ("KVM: kvm_io_bus: Add kvm_io_bus_get_dev() call")
Link: https://lore.kernel.org/all/20260626111344.802555-1-maz@kernel.org
Cc: stable@vger.kernel.org
Reviewed-by: Oliver Upton <oupton@kernel.org>
Link: https://patch.msgid.link/20260627105105.1005990-1-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 9a0bb848a37150aeccc10088e141339917d995dc ]
On some Raptor Cove CPUs, enabling uncore PMON globally at driver init
may increase power consumption even when no perf events are in use.
Drop adl_uncore_msr_init_box() and defer programming the global control
register to enable_box(), so it is only set when a box is actually used.
IMC and IMC freerunning counters use a separate control path and are
unaffected.
Fixes: 772ed05f3c5c ("perf/x86/intel/uncore: Add Alder Lake support")
Signed-off-by: Zide Chen <zide.chen@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260602144908.263680-5-zide.chen@intel.com
[ deleted adl_uncore_msr_init_box() in its 6.12 wrmsrl() spelling since the tree predates the wrmsrq() rename ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 47915e855fb38b42133e31ba917d99565f862154 upstream.
A user-only branch stack can contain branches that originate from
the kernel. As a result, kernel addresses are exposed to user space
even when PERF_SAMPLE_BRANCH_USER is requested. On AMD processors
supporting X86_FEATURE_BRS (Zen 3 only), perf can still report entries
such as SYSRET/interrupt returns for which the branch-from addresses
are in the kernel.
E.g.
$ perf record -j any,u -c 4000 -e branch-brs -o - -- \
perf bench syscall basic --loop 1000 | \
perf script -i - -F brstack|tr ' ' '\n'| \
grep -E '0x[89a-f][0-9a-f]{15}'
...
0xffffffff810001c4/0x72e2e32955eb/-/-/-/0//-
0xffffffff810001c4/0x72e2d94a9821/-/-/-/0//-
0xffffffff810001c4/0x72e2d94ffa1b/-/-/-/0//-
...
BRS provides no hardware branch filtering, so privilege level
filtering is performed entirely in software. However, amd_brs_match_plm()
only validates the branch-to address against the requested privilege
levels. For branches from the kernel to user space, the branch-from
address is left unchecked and is leaked. Extend the software filter to
also validate the branch-from address, so that any branch record whose
branch-from address is in the kernel is dropped when
PERF_SAMPLE_BRANCH_USER is requested.
Fixes: 8910075d61a3 ("perf/x86/amd: Enable branch sampling priv level filtering")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://patch.msgid.link/f05931c4f89a146c364bd5dc6b8170b1ac611c65.1783701239.git.sandipan.das@amd.com
Closes: https://lore.kernel.org/all/20260710110235.F3FD81F000E9@smtp.kernel.org/
[sandipan: backport to linux-6.6.y]
Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 47b87f469a35b5ffc81c16eee6b13a9b6c8d55c6 upstream.
spufs_mem_mmap_access() computes the local store offset as
address - vma->vm_start, but bounds-checks it against vma->vm_end
instead of the local store size. On 64-bit, offset is always well
below vma->vm_end, so the clamp never fires and len stays unbounded
against the LS_SIZE buffer returned by ctx->ops->get_ls().
Reject offsets at or beyond LS_SIZE and clamp len to the remaining
space, mirroring the guard already used by spufs_mem_mmap_fault() and
spufs_ps_fault().
Fixes: a352894d0705 ("spufs: use new vm_ops->access to allow local state access from gdb")
Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/SYBPR01MB7881EE775E8B51C09F5A29E7AF152@SYBPR01MB7881.ausprd01.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit bd83c98b988d2c560531084e296dbfb530aff829 upstream.
When krealloc() fails, free the original esi_buf before returning to
avoid a memory leak.
Fixes: 3c14b73454cf ("powerpc/pseries: Interface to represent PAPR firmware attributes")
Cc: stable@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260614142356.658212-2-thorsten.blum@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 81bbcff0c053c4f5c711c31a9b72fc492bd96c3f upstream.
A NULL pointer dereference issue is noticed in riscv's
machine_kexec_prepare(), where image->segment[i].buf might be NULL and
copied unchecked.
The NULL buf comes from ima_add_kexec_buffer(), where kbuf is added by
kexec_add_buffer(), but kbuf.buffer is NULL, then it is copied without
a check in machine_kexec_prepare():
kexec_file_load
-> kimage_file_alloc_init()
-> kimage_file_prepare_segments()
-> ima_add_kexec_buffer()
-> kexec_add_buffer()
-> machine_kexec_prepare()
-> memcpy()
Address this by adding a check before the data copy attempt.
Fixes: b7fb4d78a6ad ("RISC-V: use memcpy for kexec_file mode")
Cc: stable@vger.kernel.org
Closes: https://lore.kernel.org/kexec/CAO7dBbVftLUhd2qrh7hmijTB3PEPfZAhykCGqEfrPoOcSrrj-w@mail.gmail.com/
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Nutty Liu <nutty.liu@hotmail.com>
Signed-off-by: Tao Liu <ltao@redhat.com>
Link: https://patch.msgid.link/20260705232706.30265-2-ltao@redhat.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit bc7b086a45521a986a49045907f017e3e46c763e upstream.
Reading a word from the stack in a kretprobe crashes a risc-v kernel.
$ cd /sys/kernel/tracing/
$ echo 'r n_tty_write $stack0' > dynamic_events
$ echo 1 > events/kprobes/enable
Unable to handle kernel paging request at virtual address 0000000200000128
...
[<ffffffff80016d16>] regs_get_kernel_stack_nth+0x26/0x38
[<ffffffff80177196>] process_fetch_insn+0x3ee/0x760
[<ffffffff80177836>] kretprobe_trace_func+0x116/0x1f0
[<ffffffff8017795a>] kretprobe_dispatcher+0x4a/0x58
[<ffffffff8013572e>] kretprobe_rethook_handler+0x5e/0x90
[<ffffffff80180838>] rethook_trampoline_handler+0x70/0x108
[<ffffffff8001ba32>] arch_rethook_trampoline_callback+0x12/0x1c
[<ffffffff8001ba84>] arch_rethook_trampoline+0x48/0x94
[<ffffffff8067872a>] tty_write+0x1a/0x30
In regs_get_kernel_stack_nth, regs->sp contains an arbitrary value.
arch_rethook_trampoline saves the registers from the probed function in a
struct pt_regs. sp is not saved. Instead, sp is decremented for
arch_rethook_trampoline's local stack.
Fix this crash and save the original sp along with the other registers.
Use a0 as a temporary register, it is overwritten anyway.
Cc: stable@vger.kernel.org
Fixes: c22b0bcb1dd02 ("riscv: Add kprobes supported")
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://patch.msgid.link/20260630194010.1824039-1-martin@kaiser.cx
[pjw@kernel.org: added Fixes tag; cc'ed stable]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 018e9828eb523c638fa3d9bdf0fd4956b74555b2 upstream.
When hardware page table walker (PTW) is enabled on LoongArch, the CPU
may set _PAGE_DIRTY directly in the page table entry during a write TLB
miss, without going through the software TLB store handler. The software
TLB store handler (tlbex.S:254) sets both _PAGE_DIRTY and_PAGE_MODIFIED
together:
ori t0, t0, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED)
Since hardware PTW only sets _PAGE_DIRTY, the software-only bit, i.e.
_PAGE_MODIFIED is left unchanged. This creates a window where a PTE has
_PAGE_DIRTY set (hardware knows the page is dirty) but _PAGE_MODIFIED
clear (software is unaware).
When fork()/clone() triggers copy-on-write, __copy_present_ptes() calls
pte_wrprotect(), which unconditionally clears both the _PAGE_WRITE and
_PAGE_DIRTY bits:
pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_DIRTY);
Since _PAGE_MODIFIED was never set, the dirtiness information is lost
completely. Subsequently, when memory pressure triggers page reclaim,
page_mkclean() / try_to_unmap() sees the page as clean (i.e. pte_dirty()
returns false) and the page may be freed without writeback, causing data
corruption.
Fix this by propagating the _PAGE_DIRTY bit to the _PAGE_MODIFIED bit in
both pte_wrprotect() and pmd_wrprotect() before clearing writeable bits:
if (pte_val(pte) & _PAGE_DIRTY)
pte_val(pte) |= _PAGE_MODIFIED;
The pmd_wrprotect() fix handles the CONFIG_TRANSPARENT_HUGEPAGE case,
where pmd entries need the same treatment.
This ensures the software dirty tracking bit (checked by pte_dirty() and
pmd_dirty(), which read both the _PAGE_DIRTY and _PAGE_MODIFIED bits) is
preserved across fork COW write-protection.
The issue was found by the LTP madvise09 test case, which exercises page
reclaim after "madvise(MADV_FREE), write and fork" operation sequence on
private anonymous mappings.
Cc: stable@vger.kernel.org
Fixes: 09cfefb7fa70 ("LoongArch: Add memory management")
Co-developed-by: Tianyang Zhang <zhangtianyang@loongson.cn>
Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>
Signed-off-by: Hongchen Zhang <zhanghongchen@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit bf4a195f063b0a0805c1417f6aad1dd32ea48f0f upstream.
Currently, the while loop drops the reference to prev in each iteration.
If the loop terminates early due to a break, the final of_node_put(np)
correctly drops the reference to the current node.
However, if the loop terminates naturally because np == NULL, calling
of_node_put(np) is a no-op. This leaves the last valid node stored in
prev without its reference dropped, resulting in a node reference leak.
Fix this by changing the final `of_node_put(np)` to `of_node_put(prev)`.
Fixes: 94f9bf118f1e ("RISC-V: Fix of_node_* refcount")
Cc: stable@vger.kernel.org
Assisted-by: Gemini:gemini-3.1-pro
Signed-off-by: Zishun Yi <vulab@iscas.ac.cn>
Link: https://patch.msgid.link/20260509074040.1747800-1-vulab@iscas.ac.cn
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 98e37db4a34d3af3fb2f4648295c25b5e40b20e3 upstream.
This patch addresses a critical memory management flaw. When
CONFIG_CPUMASK_OFFSTACK is enabled, cpumask_var_t is a pointer.
Consequently, sizeof(new_mask) evaluates to the pointer size, causing
copy_from_user() to clobber the mask pointer. Furthermore, the old
logic performed copy_from_user() before allocating the mask.
Fix this by allocating new_mask first. To handle variable-sized user
masks correctly, use cpumask_size() to truncate overly large user masks
or pad undersized masks with zeros before copying the data directly into
the allocated buffer.
Fixes: 295cbf6d63165 ("[MIPS] Move FPU affinity code into separate file.")
Cc: stable@vger.kernel.org
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 5ff79e8bdc75db51e30298a75939e2308e7658e0 upstream.
In 64-bit configurations calling any firmware entry points from a kernel
thread other than the initial one will result in a situation where the
stack has been placed in the XKPHYS 64-bit memory segment.
Consequently the stack pointer is no longer a 32-bit value and when the
32-bit firmware code called uses 32-bit ALU operations to manipulate the
stack pointer, the calculated result is incorrect (in fact in the 64-bit
MIPS ISA almost all 32-bit ALU operations will produce an unpredictable
result when executed on 64-bit data) and control goes astray.
This may happen when no final console driver has been enabled in the
configuration and consequently the initial console continues being used
late into bootstrap, or with an upcoming change that will switch the zs
driver to use a platform device, which in turn will make the console
handover happen only after other kernel threads have already been
started, and the kernel will hang at:
pid_max: default: 32768 minimum: 301
or somewhat later, but always before:
cblist_init_generic: Setting adjustable number of callback queues.
has been printed.
It seems that only the prom_printf() entry point is affected. Of all
the other entry points wired only rex_slot_address() and rex_gettcinfo()
are called from a kernel thread other than the initial one, specifically
kernel_init(), and they are leaf functions that do no business with the
stack, having worked with no issue ever since 64-bit support was added
for the platform back in 2002.
To address this issue then, arrange for the stack to be switched in the
o32 wrapper as required for prom_printf() only, by supplying call_o32()
with a pointer to a chunk of initdata space, which is placed in the
CKSEG0 32-bit compatibility segment, observing that prom_printf() is
only called from console output handler and therefore with the console
lock held, implying no need for this code to be reentrant.
Other firmware entry points may be called with interrupts enabled and no
lock held, and may therefore require that call_o32() be reentrant. They
trigger no issue at this point and "if it ain't broke, don't fix it," so
just leave them alone.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v2.6.12+
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b82930a4c5dbc5c4df39c0f93d968c239f2c6885 upstream.
The gio probe function needlessly takes a device reference which is
never released and therefore prevents unbound gio devices from being
freed.
Fixes: e84de0c61905 ("MIPS: GIO bus support for SGI IP22/28")
Cc: stable@vger.kernel.org # 3.3
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c62cdd3e919bdf84c37ec46810f87cdb1736e822 upstream.
The gio bus root device is a statically allocated object which must not
be freed by kfree() on failure to register the device or bus.
Fixes: 82242d28ff8b ("MIPS: IP22: Add missing put_device call")
Cc: stable@vger.kernel.org # 3.17
Cc: Levente Kurusa <levex@linux.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 7de9a1b45f5a95b58145653c525c8fb80292d9ab upstream.
The gio device release callback was never wired up so gio devices are
not freed when the last reference is dropped.
Fixes: e84de0c61905 ("MIPS: GIO bus support for SGI IP22/28")
Cc: stable@vger.kernel.org # 3.3
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 49145bce539117db4b6e9e83c0e5ef528e361050 upstream.
ev variable is userspace controlled via event->attr.config and used
as an array index after bounds checking, but without speculation
barriers.
Add the missing array_index_nospec() call to prevent speculative
execution.
Cc: stable@vger.kernel.org
Fixes: 212188a596d1 ("[S390] perf: add support for s390x CPU counters")
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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