Linux: >> Linux Kernel >> 5.15.210 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
HID: intel-ish-hid: fix NULL-ptr-deref in ishtp_bus_remove_all_clients
During a warm reset flow, the cl->device pointer may be NULL if the
reset occurs while clients are still being enumerated. Accessing
cl->device->reference_count without a NULL check leads to a kernel panic.
This issue was identified during multi-unit warm reboot stress clycles.
Add a defensive NULL check for cl->device to ensure stability under
such intensive testing conditions.
KASAN: null-ptr-deref in range [0000000000000000-0000000000000007]
Workqueue: ish_fw_update_wq fw_reset_work_fn
Call Trace:
ishtp_bus_remove_all_clients+0xbe/0x130 [intel_ishtp]
ishtp_reset_handler+0x85/0x1a0 [intel_ishtp]
fw_reset_work_fn+0x8a/0xc0 [intel_ish_ipc]
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nfnetlink_queue: do shared-unconfirmed check before segmentation
Ulrich reports a regression with nfqueue:
If an application did not set the 'F_GSO' capability flag and a gso
packet with an unconfirmed nf_conn entry is received all packets are
now dropped instead of queued, because the check happens after
skb_gso_segment(). In that case, we did have exclusive ownership
of the skb and its associated conntrack entry. The elevated use
count is due to skb_clone happening via skb_gso_segment().
Move the check so that its peformed vs. the aggregated packet.
Then, annotate the individual segments except the first one so we
can do a 2nd check at reinject time.
For the normal case, where userspace does in-order reinjects, this avoids
packet drops: first reinjected segment continues traversal and confirms
entry, remaining segments observe the confirmed entry.
While at it, simplify nf_ct_drop_unconfirmed(): We only care about
unconfirmed entries with a refcnt > 1, there is no need to special-case
dying entries.
This only happens with UDP. With TCP, the only unconfirmed packet will
be the TCP SYN, those aren't aggregated by GRO.
Next patch adds a udpgro test case to cover this scenario.
CVSS Score
7.5
EPSS Score
0.006
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
ata: libata-scsi: avoid Non-NCQ command starvation
When a non-NCQ command is issued while NCQ commands are being executed,
ata_scsi_qc_issue() indicates to the SCSI layer that the command issuing
should be deferred by returning SCSI_MLQUEUE_XXX_BUSY. This command
deferring is correct and as mandated by the ACS specifications since
NCQ and non-NCQ commands cannot be mixed.
However, in the case of a host adapter using multiple submission queues,
when the target device is under a constant load of NCQ commands, there
are no guarantees that requeueing the non-NCQ command will be executed
later and it may be deferred again repeatedly as other submission queues
can constantly issue NCQ commands from different CPUs ahead of the
non-NCQ command. This can lead to very long delays for the execution of
non-NCQ commands, and even complete starvation for these commands in the
worst case scenario.
Since the block layer and the SCSI layer do not distinguish between
queueable (NCQ) and non queueable (non-NCQ) commands, libata-scsi SAT
implementation must ensure forward progress for non-NCQ commands in the
presence of NCQ command traffic. This is similar to what SAS HBAs with a
hardware/firmware based SAT implementation do.
Implement such forward progress guarantee by limiting requeueing of
non-NCQ commands from ata_scsi_qc_issue(): when a non-NCQ command is
received and NCQ commands are in-flight, do not force a requeue of the
non-NCQ command by returning SCSI_MLQUEUE_XXX_BUSY and instead return 0
to indicate that the command was accepted but hold on to the qc using
the new deferred_qc field of struct ata_port.
This deferred qc will be issued using the work item deferred_qc_work
running the function ata_scsi_deferred_qc_work() once all in-flight
commands complete, which is checked with the port qc_defer() callback
return value indicating that no further delay is necessary. This check
is done using the helper function ata_scsi_schedule_deferred_qc() which
is called from ata_scsi_qc_complete(). This thus excludes this mechanism
from all internal non-NCQ commands issued by ATA EH.
When a port deferred_qc is non NULL, that is, the port has a command
waiting for the device queue to drain, the issuing of all incoming
commands (both NCQ and non-NCQ) is deferred using the regular busy
mechanism. This simplifies the code and also avoids potential denial of
service problems if a user issues too many non-NCQ commands.
Finally, whenever ata EH is scheduled, regardless of the reason, a
deferred qc is always requeued so that it can be retried once EH
completes. This is done by calling the function
ata_scsi_requeue_deferred_qc() from ata_eh_set_pending(). This avoids
the need for any special processing for the deferred qc in case of NCQ
error, link or device reset, or device timeout.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
ext4: don't zero the entire extent if EXT4_EXT_DATA_PARTIAL_VALID1
When allocating initialized blocks from a large unwritten extent, or
when splitting an unwritten extent during end I/O and converting it to
initialized, there is currently a potential issue of stale data if the
extent needs to be split in the middle.
0 A B N
[UUUUUUUUUUUU] U: unwritten extent
[--DDDDDDDD--] D: valid data
|<- ->| ----> this range needs to be initialized
ext4_split_extent() first try to split this extent at B with
EXT4_EXT_DATA_ENTIRE_VALID1 and EXT4_EXT_MAY_ZEROOUT flag set, but
ext4_split_extent_at() failed to split this extent due to temporary lack
of space. It zeroout B to N and mark the entire extent from 0 to N
as written.
0 A B N
[WWWWWWWWWWWW] W: written extent
[SSDDDDDDDDZZ] Z: zeroed, S: stale data
ext4_split_extent() then try to split this extent at A with
EXT4_EXT_DATA_VALID2 flag set. This time, it split successfully and left
a stale written extent from 0 to A.
0 A B N
[WW|WWWWWWWWWW]
[SS|DDDDDDDDZZ]
Fix this by pass EXT4_EXT_DATA_PARTIAL_VALID1 to ext4_split_extent_at()
when splitting at B, don't convert the entire extent to written and left
it as unwritten after zeroing out B to N. The remaining work is just
like the standard two-part split. ext4_split_extent() will pass the
EXT4_EXT_DATA_VALID2 flag when it calls ext4_split_extent_at() for the
second time, allowing it to properly handle the split. If the split is
successful, it will keep extent from 0 to A as unwritten.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
rtmutex: Use waiter::task instead of current in remove_waiter()
remove_waiter() is used by the slowlock paths, but it is also used for
proxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from
futex_requeue().
In the latter case waiter::task is not current, but remove_waiter()
operates on current for the dequeue operation. That results in several
problems:
1) the rbtree dequeue happens without waiter::task::pi_lock being held
2) the waiter task's pi_blocked_on state is not cleared, which leaves a
dangling pointer primed for UAF around.
3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter
task
Use waiter::task instead of current in all related operations in
remove_waiter() to cure those problems.
[ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the
changelog ]
CVSS Score
7.8
EPSS Score
0.007
Published
2026-05-21
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:
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:
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:
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
0.929
Published
2026-05-11
In the Linux kernel, the following vulnerability has been resolved:
bonding: fix type confusion in bond_setup_by_slave()
kernel BUG at net/core/skbuff.c:2306!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:pskb_expand_head+0xa08/0xfe0 net/core/skbuff.c:2306
RSP: 0018:ffffc90004aff760 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88807e3c8780 RCX: ffffffff89593e0e
RDX: ffff88807b7c4900 RSI: ffffffff89594747 RDI: ffff88807b7c4900
RBP: 0000000000000820 R08: 0000000000000005 R09: 0000000000000000
R10: 00000000961a63e0 R11: 0000000000000000 R12: ffff88807e3c8780
R13: 00000000961a6560 R14: dffffc0000000000 R15: 00000000961a63e0
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe1a0ed8df0 CR3: 000000002d816000 CR4: 00000000003526f0
Call Trace:
<TASK>
ipgre_header+0xdd/0x540 net/ipv4/ip_gre.c:900
dev_hard_header include/linux/netdevice.h:3439 [inline]
packet_snd net/packet/af_packet.c:3028 [inline]
packet_sendmsg+0x3ae5/0x53c0 net/packet/af_packet.c:3108
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0xa54/0xc30 net/socket.c:2592
___sys_sendmsg+0x190/0x1e0 net/socket.c:2646
__sys_sendmsg+0x170/0x220 net/socket.c:2678
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe1a0e6c1a9
When a non-Ethernet device (e.g. GRE tunnel) is enslaved to a bond,
bond_setup_by_slave() directly copies the slave's header_ops to the
bond device:
bond_dev->header_ops = slave_dev->header_ops;
This causes a type confusion when dev_hard_header() is later called
on the bond device. Functions like ipgre_header(), ip6gre_header(),all use
netdev_priv(dev) to access their device-specific private data. When
called with the bond device, netdev_priv() returns the bond's private
data (struct bonding) instead of the expected type (e.g. struct
ip_tunnel), leading to garbage values being read and kernel crashes.
Fix this by introducing bond_header_ops with wrapper functions that
delegate to the active slave's header_ops using the slave's own
device. This ensures netdev_priv() in the slave's header functions
always receives the correct device.
The fix is placed in the bonding driver rather than individual device
drivers, as the root cause is bond blindly inheriting header_ops from
the slave without considering that these callbacks expect a specific
netdev_priv() layout.
The type confusion can be observed by adding a printk in
ipgre_header() and running the following commands:
ip link add dummy0 type dummy
ip addr add 10.0.0.1/24 dev dummy0
ip link set dummy0 up
ip link add gre1 type gre local 10.0.0.1
ip link add bond1 type bond mode active-backup
ip link set gre1 master bond1
ip link set gre1 up
ip link set bond1 up
ip addr add fe80::1/64 dev bond1
CVSS Score
7.8
EPSS Score
0.002
Published
2026-05-08