Linux: >> Linux Kernel >> 5.15.135 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
crypto: pcrypt - Fix handling of MAY_BACKLOG requests
MAY_BACKLOG requests can return EBUSY. Handle them by checking
for that value and filtering out EINPROGRESS notifications.
CVSS Score
9.8
EPSS Score
0.006
Published
2026-05-19
In the Linux kernel, the following vulnerability has been resolved:
net: qrtr: ns: Limit the maximum server registration per node
Current code does no bound checking on the number of servers added per
node. A malicious client can flood NEW_SERVER messages and exhaust memory.
Fix this issue by limiting the maximum number of server registrations to
256 per node. If the NEW_SERVER message is received for an old port, then
don't restrict it as it will get replaced. While at it, also rate limit
the error messages in the failure path of qrtr_ns_worker().
Note that the limit of 256 is chosen based on the current platform
requirements. If requirement changes in the future, this limit can be
increased.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-19
In the Linux kernel, the following vulnerability has been resolved:
lib/crypto: mpi: Fix integer underflow in mpi_read_raw_from_sgl()
Yiming reports an integer underflow in mpi_read_raw_from_sgl() when
subtracting "lzeros" from the unsigned "nbytes".
For this to happen, the scatterlist "sgl" needs to occupy more bytes
than the "nbytes" parameter and the first "nbytes + 1" bytes of the
scatterlist must be zero. Under these conditions, the while loop
iterating over the scatterlist will count more zeroes than "nbytes",
subtract the number of zeroes from "nbytes" and cause the underflow.
When commit 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers") originally
introduced the bug, it couldn't be triggered because all callers of
mpi_read_raw_from_sgl() passed a scatterlist whose length was equal to
"nbytes".
However since commit 63ba4d67594a ("KEYS: asymmetric: Use new crypto
interface without scatterlists"), the underflow can now actually be
triggered. When invoking a KEYCTL_PKEY_ENCRYPT system call with a
larger "out_len" than "in_len" and filling the "in" buffer with zeroes,
crypto_akcipher_sync_prep() will create an all-zero scatterlist used for
both the "src" and "dst" member of struct akcipher_request and thereby
fulfil the conditions to trigger the bug:
sys_keyctl()
keyctl_pkey_e_d_s()
asymmetric_key_eds_op()
software_key_eds_op()
crypto_akcipher_sync_encrypt()
crypto_akcipher_sync_prep()
crypto_akcipher_encrypt()
rsa_enc()
mpi_read_raw_from_sgl()
To the user this will be visible as a DoS as the kernel spins forever,
causing soft lockup splats as a side effect.
Fix it.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-19
In the Linux kernel, the following vulnerability has been resolved:
ptrace: slightly saner 'get_dumpable()' logic
The 'dumpability' of a task is fundamentally about the memory image of
the task - the concept comes from whether it can core dump or not - and
makes no sense when you don't have an associated mm.
And almost all users do in fact use it only for the case where the task
has a mm pointer.
But we have one odd special case: ptrace_may_access() uses 'dumpable' to
check various other things entirely independently of the MM (typically
explicitly using flags like PTRACE_MODE_READ_FSCREDS). Including for
threads that no longer have a VM (and maybe never did, like most kernel
threads).
It's not what this flag was designed for, but it is what it is.
The ptrace code does check that the uid/gid matches, so you do have to
be uid-0 to see kernel thread details, but this means that the
traditional "drop capabilities" model doesn't make any difference for
this all.
Make it all make a *bit* more sense by saying that if you don't have a
MM pointer, we'll use a cached "last dumpability" flag if the thread
ever had a MM (it will be zero for kernel threads since it is never
set), and require a proper CAP_SYS_PTRACE capability to override.
CVSS Score
7.1
EPSS Score
0.014
Published
2026-05-15
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate inherited ACE SID length
smb_inherit_dacl() walks the parent directory DACL loaded from the
security descriptor xattr. It verifies that each ACE contains the fixed
SID header before using it, but does not verify that the variable-length
SID described by sid.num_subauth is fully contained in the ACE.
A malformed inheritable ACE can advertise more subauthorities than are
present in the ACE. compare_sids() may then read past the ACE.
smb_set_ace() also clamps the copied destination SID, but used the
unchecked source SID count to compute the inherited ACE size. That could
advance the temporary inherited ACE buffer pointer and nt_size accounting
past the allocated buffer.
Fix this by validating the parent ACE SID count and SID length before
using the SID during inheritance. Compute the inherited ACE size from the
copied SID so the size matches the bounded destination SID. Reject the
inherited DACL if size accumulation would overflow smb_acl.size or the
security descriptor allocation size.
CVSS Score
8.8
EPSS Score
0.004
Published
2026-05-15
In the Linux kernel, the following vulnerability has been resolved:
ASoC: amd: acp3x-rt5682-max9836: Add missing error check for clock acquisition
The acp3x_5682_init() function did not check the return value of
clk_get(), which could lead to dereferencing error pointers in
rt5682_clk_enable().
Fix this by:
1. Changing clk_get() to the device-managed devm_clk_get().
2. Adding proper IS_ERR() checks for both clock acquisitions.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-13
In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Set/clear CR8 write interception when AVIC is (de)activated
Explicitly set/clear CR8 write interception when AVIC is (de)activated to
fix a bug where KVM leaves the interception enabled after AVIC is
activated. E.g. if KVM emulates INIT=>WFS while AVIC is deactivated, CR8
will remain intercepted in perpetuity.
On its own, the dangling CR8 intercept is "just" a performance issue, but
combined with the TPR sync bug fixed by commit d02e48830e3f ("KVM: SVM:
Sync TPR from LAPIC into VMCB::V_TPR even if AVIC is active"), the danging
intercept is fatal to Windows guests as the TPR seen by hardware gets
wildly out of sync with reality.
Note, VMX isn't affected by the bug as TPR_THRESHOLD is explicitly ignored
when Virtual Interrupt Delivery is enabled, i.e. when APICv is active in
KVM's world. I.e. there's no need to trigger update_cr8_intercept(), this
is firmly an SVM implementation flaw/detail.
WARN if KVM gets a CR8 write #VMEXIT while AVIC is active, as KVM should
never enter the guest with AVIC enabled and CR8 writes intercepted.
[Squash fix to avic_deactivate_vmcb. - Paolo]
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-13
In the Linux kernel, the following vulnerability has been resolved:
mmc: core: Avoid bitfield RMW for claim/retune flags
Move claimed and retune control flags out of the bitfield word to
avoid unrelated RMW side effects in asynchronous contexts.
The host->claimed bit shared a word with retune flags. Writes to claimed
in __mmc_claim_host() or retune_now in mmc_mq_queue_rq() can overwrite
other bits when concurrent updates happen in other contexts, triggering
spurious WARN_ON(!host->claimed). Convert claimed, can_retune,
retune_now and retune_paused to bool to remove shared-word coupling.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-13
In the Linux kernel, the following vulnerability has been resolved:
iio: chemical: sps30_i2c: fix buffer size in sps30_i2c_read_meas()
sizeof(num) evaluates to sizeof(size_t) (8 bytes on 64-bit) instead
of the intended __be32 element size (4 bytes). Use sizeof(*meas) to
correctly match the buffer element type.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-05-13
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present
The DATA-packet handler in rxrpc_input_call_event() and the RESPONSE
handler in rxrpc_verify_response() copy the skb to a linear one before
calling into the security ops only when skb_cloned() is true. An skb
that is not cloned but still carries externally-owned paged fragments
(e.g. SKBFL_SHARED_FRAG set by splice() into a UDP socket via
__ip_append_data, or a chained skb_has_frag_list()) falls through to
the in-place decryption path, which binds the frag pages directly into
the AEAD/skcipher SGL via skb_to_sgvec().
Extend the gate to also unshare when skb_has_frag_list() or
skb_has_shared_frag() is true. This catches the splice-loopback vector
and other externally-shared frag sources while preserving the
zero-copy fast path for skbs whose frags are kernel-private (e.g. NIC
page_pool RX, GRO). The OOM/trace handling already in place is reused.
CVSS Score
7.8
EPSS Score
0.928
Published
2026-05-11