Found while auditing the same pattern Sashiko reported in
rt6_fill_node() [1]. Apply the same fix as
commit f8d8ce1b51 ("ipv6: fix possible infinite loop in fib6_info_uses_dev()").
Writers holding tb6_lock can list_del_rcu(&first->fib6_siblings)
without waiting for RCU readers; first->fib6_siblings.next then
still points into the old ring and this softirq-side walker never
reaches &first->fib6_siblings as its terminator. fib6_purge_rt()
always WRITE_ONCE()s first->fib6_nsiblings to 0 before
list_del_rcu(), so an inside-loop check is a reliable detach signal.
[1] https://sashiko.dev/#/patchset/20260526020227.4857-1-jiayuan.chen%40linux.dev
Fixes: d9ccb18f83 ("ipv6: Fix soft lockups in fib6_select_path under high next hop churn")
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260527053133.180695-2-jiayuan.chen@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Sashiko reported this issue [1]. Apply the same fix as
commit f8d8ce1b51 ("ipv6: fix possible infinite loop in fib6_info_uses_dev()").
Writers holding tb6_lock can list_del_rcu(&rt->fib6_siblings)
without waiting for RCU readers; rt->fib6_siblings.next then still
points into the old ring and this softirq-side walker never reaches
&rt->fib6_siblings, causing a CPU stall. fib6_del_route() always
WRITE_ONCE()s rt->fib6_nsiblings to 0 before list_del_rcu(), so an
inside-loop check is a reliable detach signal.
[1] https://sashiko.dev/#/patchset/20260526020227.4857-1-jiayuan.chen%40linux.dev
Fixes: d9ccb18f83 ("ipv6: Fix soft lockups in fib6_select_path under high next hop churn")
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260527053133.180695-1-jiayuan.chen@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When bpf_msg_push_data() inserts data in the middle of a scatterlist
entry, it splits the original entry into a left fragment and a right
fragment.
The right fragment offset is page-local, but the code advances it with
`start`, which is the message-global insertion point. For inserts into a
non-first SG entry, this over-advances the offset and leaves the split
layout inconsistent.
Advance the right fragment offset by the fragment-local delta,
`start - offset`, which matches the length removed from the front of the
original entry.
Fixes: 6fff607e2f ("bpf: sk_msg program helper bpf_msg_push_data")
Cc: stable@kernel.org
Reported-by: Yuan Tan <yuantan098@gmail.com>
Reported-by: Zhengchuan Liang <zcliangcn@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Signed-off-by: Yuqi Xu <xuyq21@lenovo.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Link: https://patch.msgid.link/8b129d10566aa3eb43f61a8f9757bcf51707d324.1779636774.git.xuyq21@lenovo.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
virtio_transport_send_pkt_info() allocates or reuses the zerocopy uarg
before entering the send loop, but virtio_transport_alloc_skb() still
fills the skb before it inherits that uarg. When fixed-buffer vectored
zerocopy hits MAX_SKB_FRAGS, io_sg_from_iter() may partially attach
managed frags and return -EMSGSIZE. The rollback path call kfree_skb()
to free an skb that carries SKBFL_MANAGED_FRAG_REFS but no uarg, so
skb_release_data() falls through to ordinary frag unref.
Pass the uarg into virtio_transport_alloc_skb() and bind it immediately
before virtio_transport_fill_skb(). This keeps control or no-payload skbs
untouched while ensuring success and rollback share one lifetime rule.
Fixes: 581512a6dc ("vsock/virtio: MSG_ZEROCOPY flag support")
Signed-off-by: Lin Ma <malin89@huawei.com>
Signed-off-by: Rongzhen Cui <cuirongzhen@huawei.com>
Signed-off-by: Jingguo Tan <tanjingguo@huawei.com>
Acked-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20260527023301.1075581-1-malin89@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Use READ_ONCE() when reading entries/indices from the guest-accessible
Page State Change buffer to defend against TOCTOU bugs.
Don't bother with READ_ONCE()/WRITE_ONCE() for cases where KVM is writing
(and not consuming the result!), as the guest isn't supposed to touch the
buffer while it's being processed. I.e. using READ_ONCE() is all about
protecting against misbehaving guests.
Fixes: 9b54e248d2 ("KVM: SEV: Add support to handle Page State Change VMGEXIT")
Cc: stable@vger.kernel.org
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260501202250.2115252-11-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When processing Page State Change (PSC) requests, validate the PSC buffer
against the effective size of the scratch area, which could be less than
the maximum size if the guest provided a pointer that isn't exactly at the
start of the GHCB shared buffer.
Fixes: 9b54e248d2 ("KVM: SEV: Add support to handle Page State Change VMGEXIT")
Cc: stable@vger.kernel.org
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260501202250.2115252-10-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When setting the length of the GHCB scratch area, and the area is in the
GHCB shared buffer, set the effective length of the scratch area to the max
possible size given the start of the guest-provided pointer, and the end of
the shared buffer.
The code was "fine" when first introduced, as KVM doesn't consult the
length of the buffer when emulating MMIO, because the passed in @len always
specifies the *max* size required. But for PSC requests, the incoming @len
is just the minimum length (to process the header), and KVM needs to know
the full size of the scratch area to avoid buffer overflows (spoiler alert).
Opportunistically rename @len => @min_len to better reflect its role.
Fixes: 9b54e248d2 ("KVM: SEV: Add support to handle Page State Change VMGEXIT")
Cc: stable@vger.kernel.org
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260501202250.2115252-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When handling a Page State Change (PSC) #VMGEXIT use the size of the PSC
header as the minimum size for the scratch area. Per the GHCB spec, PSC
requests do NOT provide the length, i.e. using control->exit_info_2 for the
length is completely made up behavior. The existing code "works", e.g.
even though Linux-as-a-guest always passes '0', because KVM doesn't do
anything with the length when the request is in the GHCB's shared buffer.
Use the header as the min length. Once the header is retrieved, KVM can
use the specified indices to compute the full size of the request.
Fixes: 9b54e248d2 ("KVM: SEV: Add support to handle Page State Change VMGEXIT")
Cc: stable@vger.kernel.org
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260501202250.2115252-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Explicitly ignore Port I/O requests of length '0' (or count '0'), so that
setting up the software scratch area (and other code) doesn't have to
worry about underflowing the length, and to allow for WARNing on trying
to configure the scratch area with len==0.
Fixes: 291bd20d5d ("KVM: SVM: Add initial support for a VMGEXIT VMEXIT")
Cc: stable@vger.kernel.org
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260501202250.2115252-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When using GHCB v2+, reject MMIO requests that are larger than 8 bytes.
Per the GHCB spec:
SW_EXITINFO2 must be less than or equal to 0x7fffffff for version 1 and
less than or equal to 0x8 for all other versions.
Fixes: 4af663c2f6 ("KVM: SEV: Allow per-guest configuration of GHCB protocol version")
Cc: stable@vger.kernel.org
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260501202250.2115252-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As per the GHCB spec, when using GHCB v2+ require the software scratch area
to reside in the GHCB's shared buffer. Note, things like Page State Change
(PSC) requests _rely_ on this behavior, as the guest can't provide a length
when making the request, i.e. the size of the guest payload is bounded by
the size of the shared buffer.
Failure to force usage of the GHCB, and a slew of other flaws, lets a
malicious SNP guest corrupt host kernel heap memory, and leak host heap
layout information.
setup_vmgexit_scratch() allocates a buffer via kvzalloc(exit_info_2),
where exit_info_2 is guest-controlled. With exit_info_2=24, this yields
a 24-byte allocation in kmalloc-cg-32 (32-byte slab objects). The buffer
holds an 8-byte psc_hdr followed by 8-byte psc_entry structs, so only
entries[0] and entries[1] are in-bounds.
snp_begin_psc() validates end_entry against VMGEXIT_PSC_MAX_COUNT (253)
but NOT against the actual buffer size:
idx_end = hdr->end_entry;
if (idx_end >= VMGEXIT_PSC_MAX_COUNT) { // checks 253, not buffer
snp_complete_psc(svm, ...);
return 1;
}
for (idx = idx_start; idx <= idx_end; idx++) {
entry_start = entries[idx]; // OOB when idx >= 2
The guest sets end_entry=10+, causing the host to iterate entries[2+]
which are OOB into adjacent slab objects. For each OOB entry:
- The host reads 8 bytes (OOB READ / info leak oracle)
- If the data passes PSC validation, __snp_complete_one_psc() writes
cur_page = 1 or 512 into the entry (OOB WRITE, sev.c:3806)
- If validation fails, the error response reveals whether adjacent
memory is zero vs non-zero (information disclosure to guest)
The guest controls allocation size (exit_info_2), entry range
(cur_entry/end_entry), and can fire unlimited VMGEXITs to repeatedly
hit different slab positions.
By exploiting the variety of bugs, a malicious SEV-SNP guest can:
- OOB read adjacent kmalloc-cg-32 objects (heap layout disclosure)
- OOB write cur_page bits into adjacent objects (heap corruption)
- Trigger use-after-free conditions across VMGEXITs
E.g. with KASAN enabled, a single insmod of the PoC guest module
produces 73 KASAN reports:
BUG: KASAN: slab-out-of-bounds in snp_begin_psc+0x126/0x890
Read of size 8 at addr ffff888219ffb5e0 by task qemu-system-x86/2199
BUG: KASAN: slab-out-of-bounds in snp_begin_psc+0x468/0x890
Write of size 8 at addr ffff888351566648 by task qemu-system-x86/2199
The buggy address belongs to the object at ffff888XXXXXXXXX
which belongs to the cache kmalloc-cg-32 of size 32
The buggy address is located N bytes to the right of
allocated 32-byte region [ffff888XXXXXXXXX, ffff888XXXXXXXXX)
Breakdown:
62 slab-out-of-bounds (reads + writes past allocation)
7 slab-use-after-free
4 use-after-free
All credit to Stan for the wonderful description and reproducer!
Reported-by: Stan Shaw <shawstan96@gmail.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Peter Gonda <pgonda@google.com>
Cc: Jacky Li <jackyli@google.com>
Fixes: 4af663c2f6 ("KVM: SEV: Allow per-guest configuration of GHCB protocol version")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Roth <michael.roth@amd.com>
[sean: write changelog]
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260501202250.2115252-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull block fix from Jens Axboe:
"Just a single fix for the block side, making a slight tweak to a fix
from this cycle"
* tag 'block-7.1-20260529' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
blk-mq: reinsert cached request to the list
Pull io_uring fix from Jens Axboe:
"Just a single fix for a regression introduced in this cycle, where
we should ensure the node is visible before the entry is added to
the tctx list"
* tag 'io_uring-7.1-20260529' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
io_uring/tctx: set ->io_uring before publishing the tctx node
KVM/arm64 fixes for 7.1, take #4
- Restore CONFIG_PKVM_DISABLE_STAGE2_ON_PANIC to its former glory by
making sure the config symbol is correctly spelled out in the code
- Don't reset the AArch32 view of the PMU counters to zero when the
guest is writing to them
- Fix an assorted collection of memory leaks in the newly added tracing
code
- Fix the capping of ZCR_EL2 which could be used in an unsanitised way
by an L2 guest
KVM x86 fixes for 7.1-rcN
- Include the kernel's linux/mman.h in KVM selftests to ensure MADV_COLLAPSE
is defined, as older libc versions may not provide it.
- Include execinfo.h if and only if KVM selftests are building against glibc,
and provide a test_dump_stack() for non-glibc builds.
- Fudge around an RCU splat in the emegerncy reboot code that is technically
a legitimate flaw, but in practice is a non-issue and fixing the flaw, e.g.
by adding locking, would incur meaningful risk, i.e. do more harm than good.
- Rate-limit global clock updates once again (but without delayed work), as
KVM was subtly relying on the old rate-limiting for NPT correction to guard
against "update storms" when running without a master clock on systems with
overcommitted CPUs.
- Fix a brown paper bag goof where KVM checked if ERAPS is "dirty" instead of
marking it dirty when emulating INVPCID.
- Flush the TLB when transitioning from xAVIC => x2AVIC to ensure the CPU TLB
doesn't contain AVIC-tagged entries for the APIC base GPA.
Pull Compute Express Link (CXL) fixes from Dave Jiang:
- cxl/test: update mock dev array before calling platform_device_add()
* tag 'cxl-fixes-7.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
cxl/test: Update mock dev array before calling platform_device_add()
Pull sound fixes from Takashi Iwai:
"A collection of recent small fixes and quirks.
We still see a bit more changes than wished, but most of them are
device-specific ones that are pretty safe to apply, while a core fix
is a typical UAF fix for PCM core that was recently caught by fuzzer;
so overall nothing looks really worrisome.
Core:
- Fix a UAF in PCM OSS proc interface
HD-audio:
- Fix memory leaks in CS35L56 driver
- Various device-specific quirks for Realtek and CS420x codecs
USB-audio:
- Quirk for TAE1160 USB Audio
- Fix for Scarlett2 Gen4 direct monitor gain
ASoC:
- Fixes for QCom q6asm-dai, Intel bytcht_es8316, and simple-mux codec
FireWire:
- Fix for Motu DSP event queue protection"
* tag 'sound-7.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ASoC: codecs: simple-mux: Fix enum control bounds check
ALSA: usb-audio: Add iface reset and delay quirk for TAE1160 USB Audio
ALSA: hda/cs420x: Add CS4208 fixup for iMac16,1
ALSA: hda/realtek: add quirk for HP Dragonfly Folio G3 2-in-1
ALSA: hda/realtek: Fix speaker output on ASUS ROG Strix G615LP
ASoC: qcom: q6asm-dai: use pointer type with kzalloc_obj()
ASoC: qcom: q6asm-dai: remove unnecessary braces
ASoC: qcom: q6asm-dai: fix error handling in prepare and set_params
ASoC: qcom: q6asm-dai: close stream only when running
ASoC: qcom: q6asm-dai: do not set stream state in event and trigger callbacks
ASoC: Intel: bytcht_es8316: Fix MCLK leak on init errors
ALSA: hda/realtek: Limit mic boost on Positivo DN140
ALSA: scarlett2: Fix 2i2 Gen 4 direct monitor gain on firmware 2417
ALSA: pcm: oss: Fix setup list UAF on proc write error
ALSA: hda: cs35l56: Fix system name string leaks
ALSA: hda/realtek: Add HDA_CODEC_QUIRK for Lenovo Yoga Slim 7 14AGP11
ALSA: hda/realtek: Fix incorrect comment for ALC299_FIXUP_PREDATOR_SPK
ALSA: firewire-motu: Protect register DSP event queue positions
Pull HID fixes from Benjamin Tissoires:
- buffer overflow fix for lenovo (Kean) and wacom (Lee Jones) drivers
- segfaults prevention in lenovo-go driver when used with an emulated
device (Louis Clinckx)
- cleanup of resources in u2fzero (Myeonghun Pak)
- a quirk for a USB mouse and a cleanup in hid.h (hlleng and Liu Kai)
* tag 'hid-for-linus-2026052801' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid:
HID: wacom: Fix OOB write in wacom_hid_set_device_mode()
HID: lenovo-go: drop dead NULL check on to_usb_interface()
HID: lenovo-go: reject non-USB transports in probe
HID: lenovo: Fix buffer over-read and unaligned access in X12 Tab raw_event handler
HID: quirks: Add ALWAYS_POLL quirk for SIGMACHIP USB mouse
HID: remove duplicate hid_warn_ratelimited definition
HID: u2fzero: free allocated URB on probe errors
I met one suspend/resume issue with sdr104 capable sdio wifi card (with
"keep-power-in-suspend" set in DT property):
After resuming from suspend to ram, the sdio wifi card stops working.
Further debug shows that although ios shows the sdio card is at sdr104
mode, the voltage is still at 3V3. This is due to missing the calling
of ->start_signal_voltage_switch() in sdhci_resume_host().
Fix this issue by adding ->start_signal_voltage_switch() in
sdhci_resume_host(). This also matches what we do for
sdhci_runtime_resume_host().
Then the question is: why this issue hasn't reported and fixed for so
long time. IMHO, several reasons: Some host controllers just kick off
the runtime resume for system resume, so they benefit from the well
supported runtime pm code; Some platforms just use the old sdio wifi
card which doesn't need signal voltage switch at all, the default
voltage is 3v3 after resuming.
Fixes: 6308d2905b ("mmc: sdhci: add quirk for keeping card power during suspend")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
The really old controllers (rk2928, rk3066, rk3188) do not support UHS
speeds at all, and thus never handled phase data.
For that reason it never had a parse_dt callback and no driver private
data at all.
Commit ff6f0286c8 ("mmc: dw_mmc-rockchip: Add memory clock auto-gating
support") makes the private data sort of mandatory, because the init
function checks whether phases are configured internally or through the
clock controller.
This results in the old SoCs then experiencing NULL-pointer dereferences
when they try to access that private-data struct.
While we could have if (priv) conditionals in all places, it's way less
cluttery to just give the old types their private-data struct.
Fixes: ff6f0286c8 ("mmc: dw_mmc-rockchip: Add memory clock auto-gating support")
Cc: stable@vger.kernel.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
