Linux: >> Linux Kernel >> 6.12.95 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
spi: microchip-core-qspi: control built-in cs manually
The coreQSPI IP supports only a single chip select, which is
automagically operated by the hardware - set low when the transmit
buffer first gets written to and set high when the number of bytes
written to the TOTALBYTES field of the FRAMES register have been sent on
the bus. Additional devices must use GPIOs for their chip selects.
It was reported to me that if there are two devices attached to this
QSPI controller that the in-built chip select is set low while linux
tries to access the device attached to the GPIO.
This went undetected as the boards that connected multiple devices to
the SPI controller all exclusively used GPIOs for chip selects, not
relying on the built-in chip select at all. It turns out that this was
because the built-in chip select, when controlled automagically, is set
low when active and high when inactive, thereby ruling out its use for
active-high devices or devices that need to transmit with the chip
select disabled.
Modify the driver so that it controls chip select directly, retaining
the behaviour for mem_ops of setting the chip select active for the
entire duration of the transfer in the exec_op callback. For regular
transfers, implement the set_cs callback for the core to use.
As part of this, the existing setup callback, mchp_coreqspi_setup_op(),
is removed. Modifying the CLKIDLE field is not safe to do during
operation when there are multiple devices, so this code is removed
entirely. Setting the MASTER and ENABLE fields is something that can be
done once at probe, it doesn't need to be re-run for each device.
Instead the new setup callback sets the built-in chip select to its
inactive state for active-low devices, as the reset value of the chip
select in software controlled mode is low.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-28
In the Linux kernel, the following vulnerability has been resolved:
8021q: delete cleared egress QoS mappings
vlan_dev_set_egress_priority() currently keeps cleared egress
priority mappings in the hash as tombstones. Repeated set/clear cycles
with distinct skb priorities therefore accumulate mapping nodes until
device teardown and leak memory.
Delete mappings when vlan_prio is cleared instead of keeping tombstones.
Now that the egress mapping lists are RCU protected, the node can be
unlinked safely and freed after a grace period.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-28
In the Linux kernel, the following vulnerability has been resolved:
dm-verity-fec: fix reading parity bytes split across blocks (take 3)
fec_decode_bufs() assumes that the parity bytes of the first RS codeword
it decodes are never split across parity blocks.
This assumption is false. Consider v->fec->block_size == 4096 &&
v->fec->roots == 17 && fio->nbufs == 1, for example. In that case, each
call to fec_decode_bufs() consumes v->fec->roots * (fio->nbufs <<
DM_VERITY_FEC_BUF_RS_BITS) = 272 parity bytes.
Considering that the parity data for each message block starts on a
block boundary, the byte alignment in the parity data will iterate
through 272*i mod 4096 until the 3 parity blocks have been consumed. On
the 16th call (i=15), the alignment will be 4080 bytes into the first
block. Only 16 bytes remain in that block, but 17 parity bytes will be
needed. The code reads out-of-bounds from the parity block buffer.
Fortunately this doesn't normally happen, since it can occur only for
certain non-default values of fec_roots *and* when the maximum number of
buffers couldn't be allocated due to low memory. For example with
block_size=4096 only the following cases are affected:
fec_roots=17: nbufs in [1, 3, 5, 15]
fec_roots=19: nbufs in [1, 229]
fec_roots=21: nbufs in [1, 3, 5, 13, 15, 39, 65, 195]
fec_roots=23: nbufs in [1, 89]
Regardless, fix it by refactoring how the parity blocks are read.
CVSS Score
7.1
EPSS Score
0.001
Published
2026-05-28
In the Linux kernel, the following vulnerability has been resolved:
tpm2-sessions: Fix missing tpm_buf_destroy() in tpm2_read_public()
tpm2_read_public() calls tpm_buf_init() but fails to call
tpm_buf_destroy() on two exit paths, leaking a page allocation:
1. When name_size() returns an error (unrecognized hash algorithm),
the function returns directly without destroying the buffer.
2. On the success path, the buffer is never destroyed before
returning.
All other error paths in the function correctly call
tpm_buf_destroy() before returning.
Fix both by adding the missing tpm_buf_destroy() calls.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
wifi: rtw88: check for PCI upstream bridge existence
pci_upstream_bridge() returns NULL if the device is on a root bus. If
8821CE is installed in the system with such a PCI topology, the probing
routine will crash. This has probably been unnoticed as 8821CE is mostly
supplied in laptops where there is a PCI-to-PCI bridge located upstream
from the device. However the card might be installed on a system with
different configuration.
Check if the bridge does exist for the specific workaround to be applied.
Found by Linux Verification Center (linuxtesting.org) with Svace static
analysis tool.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
mm/vmalloc: take vmap_purge_lock in shrinker
decay_va_pool_node() can be invoked concurrently from two paths:
__purge_vmap_area_lazy() when pools are being purged, and the shrinker via
vmap_node_shrink_scan().
However, decay_va_pool_node() is not safe to run concurrently, and the
shrinker path currently lacks serialization, leading to races and possible
leaks.
Protect decay_va_pool_node() by taking vmap_purge_lock in the shrinker
path to ensure serialization with purge users.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
KVM: nSVM: Avoid clearing VMCB_LBR in vmcb12
svm_copy_lbrs() always marks VMCB_LBR dirty in the destination VMCB.
However, nested_svm_vmexit() uses it to copy LBRs to vmcb12, and
clearing clean bits in vmcb12 is not architecturally defined.
Move vmcb_mark_dirty() to callers and drop it for vmcb12.
This also facilitates incoming refactoring that does not pass the entire
VMCB to svm_copy_lbrs().
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
ceph: fix num_ops off-by-one when crypto allocation fails
move_dirty_folio_in_page_array() may fail if the file is encrypted, the
dirty folio is not the first in the batch, and it fails to allocate a
bounce buffer to hold the ciphertext. When that happens,
ceph_process_folio_batch() simply redirties the folio and flushes the
current batch -- it can retry that folio in a future batch.
However, if this failed folio is not contiguous with the last folio that
did make it into the batch, then ceph_process_folio_batch() has already
incremented `ceph_wbc->num_ops`; because it doesn't follow through and
add the discontiguous folio to the array, ceph_submit_write() -- which
expects that `ceph_wbc->num_ops` accurately reflects the number of
contiguous ranges (and therefore the required number of "write extent"
ops) in the writeback -- will panic the kernel:
BUG_ON(ceph_wbc->op_idx + 1 != req->r_num_ops);
This issue can be reproduced on affected kernels by writing to
fscrypt-enabled CephFS file(s) with a 4KiB-written/4KiB-skipped/repeat
pattern (total filesize should not matter) and gradually increasing the
system's memory pressure until a bounce buffer allocation fails.
Fix this crash by decrementing `ceph_wbc->num_ops` back to the correct
value when move_dirty_folio_in_page_array() fails, but the folio already
started counting a new (i.e. still-empty) extent.
The defect corrected by this patch has existed since 2022 (see first
`Fixes:`), but another bug blocked multi-folio encrypted writeback until
recently (see second `Fixes:`). The second commit made it into 6.18.16,
6.19.6, and 7.0-rc1, unmasking the panic in those versions. This patch
therefore fixes a regression (panic) introduced by cac190c7674f.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
selinux: fix overlayfs mmap() and mprotect() access checks
The existing SELinux security model for overlayfs is to allow access if
the current task is able to access the top level file (the "user" file)
and the mounter's credentials are sufficient to access the lower
level file (the "backing" file). Unfortunately, the current code does
not properly enforce these access controls for both mmap() and mprotect()
operations on overlayfs filesystems.
This patch makes use of the newly created security_mmap_backing_file()
LSM hook to provide the missing backing file enforcement for mmap()
operations, and leverages the backing file API and new LSM blob to
provide the necessary information to properly enforce the mprotect()
access controls.
CVSS Score
7.1
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
KVM: nSVM: Always use NextRIP as vmcb02's NextRIP after first L2 VMRUN
For guests with NRIPS disabled, L1 does not provide NextRIP when running
an L2 with an injected soft interrupt, instead it advances the current RIP
before running it. KVM uses the current RIP as the NextRIP in vmcb02 to
emulate a CPU without NRIPS.
However, after L2 runs the first time, NextRIP will be updated by the CPU
and/or KVM, and the current RIP is no longer the correct value to use in
vmcb02. Hence, after save/restore, use the current RIP if and only if a
nested run is pending, otherwise use NextRIP. Give soft_int_next_rip the
same treatment, as it's the same logic, just for a narrower use case.
[sean: give soft_int_next_rip the same treatment]
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-27