Linux: >> Linux Kernel >> 6.18.7 Security Vulnerabilities
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:
usb: xhci: Prevent interrupt storm on host controller error (HCE)
The xHCI controller reports a Host Controller Error (HCE) in UAS Storage
Device plug/unplug scenarios on Android devices. HCE is checked in
xhci_irq() function and causes an interrupt storm (since the interrupt
isn’t cleared), leading to severe system-level faults.
When the xHC controller reports HCE in the interrupt handler, the driver
only logs a warning and assumes xHC activity will stop as stated in xHCI
specification. An interrupt storm does however continue on some hosts
even after HCE, and only ceases after manually disabling xHC interrupt
and stopping the controller by calling xhci_halt().
Add xhci_halt() to xhci_irq() function where STS_HCE status is checked,
mirroring the existing error handling pattern used for STS_FATAL errors.
This only fixes the interrupt storm. Proper HCE recovery requires resetting
and re-initializing the xHC.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-13
In the Linux kernel, the following vulnerability has been resolved:
net: usb: lan78xx: fix WARN in __netif_napi_del_locked on disconnect
Remove redundant netif_napi_del() call from disconnect path.
A WARN may be triggered in __netif_napi_del_locked() during USB device
disconnect:
WARNING: CPU: 0 PID: 11 at net/core/dev.c:7417 __netif_napi_del_locked+0x2b4/0x350
This happens because netif_napi_del() is called in the disconnect path while
NAPI is still enabled. However, it is not necessary to call netif_napi_del()
explicitly, since unregister_netdev() will handle NAPI teardown automatically
and safely. Removing the redundant call avoids triggering the warning.
Full trace:
lan78xx 1-1:1.0 enu1: Failed to read register index 0x000000c4. ret = -ENODEV
lan78xx 1-1:1.0 enu1: Failed to set MAC down with error -ENODEV
lan78xx 1-1:1.0 enu1: Link is Down
lan78xx 1-1:1.0 enu1: Failed to read register index 0x00000120. ret = -ENODEV
------------[ cut here ]------------
WARNING: CPU: 0 PID: 11 at net/core/dev.c:7417 __netif_napi_del_locked+0x2b4/0x350
Modules linked in: flexcan can_dev fuse
CPU: 0 UID: 0 PID: 11 Comm: kworker/0:1 Not tainted 6.16.0-rc2-00624-ge926949dab03 #9 PREEMPT
Hardware name: SKOV IMX8MP CPU revC - bd500 (DT)
Workqueue: usb_hub_wq hub_event
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __netif_napi_del_locked+0x2b4/0x350
lr : __netif_napi_del_locked+0x7c/0x350
sp : ffffffc085b673c0
x29: ffffffc085b673c0 x28: ffffff800b7f2000 x27: ffffff800b7f20d8
x26: ffffff80110bcf58 x25: ffffff80110bd978 x24: 1ffffff0022179eb
x23: ffffff80110bc000 x22: ffffff800b7f5000 x21: ffffff80110bc000
x20: ffffff80110bcf38 x19: ffffff80110bcf28 x18: dfffffc000000000
x17: ffffffc081578940 x16: ffffffc08284cee0 x15: 0000000000000028
x14: 0000000000000006 x13: 0000000000040000 x12: ffffffb0022179e8
x11: 1ffffff0022179e7 x10: ffffffb0022179e7 x9 : dfffffc000000000
x8 : 0000004ffdde8619 x7 : ffffff80110bcf3f x6 : 0000000000000001
x5 : ffffff80110bcf38 x4 : ffffff80110bcf38 x3 : 0000000000000000
x2 : 0000000000000000 x1 : 1ffffff0022179e7 x0 : 0000000000000000
Call trace:
__netif_napi_del_locked+0x2b4/0x350 (P)
lan78xx_disconnect+0xf4/0x360
usb_unbind_interface+0x158/0x718
device_remove+0x100/0x150
device_release_driver_internal+0x308/0x478
device_release_driver+0x1c/0x30
bus_remove_device+0x1a8/0x368
device_del+0x2e0/0x7b0
usb_disable_device+0x244/0x540
usb_disconnect+0x220/0x758
hub_event+0x105c/0x35e0
process_one_work+0x760/0x17b0
worker_thread+0x768/0xce8
kthread+0x3bc/0x690
ret_from_fork+0x10/0x20
irq event stamp: 211604
hardirqs last enabled at (211603): [<ffffffc0828cc9ec>] _raw_spin_unlock_irqrestore+0x84/0x98
hardirqs last disabled at (211604): [<ffffffc0828a9a84>] el1_dbg+0x24/0x80
softirqs last enabled at (211296): [<ffffffc080095f10>] handle_softirqs+0x820/0xbc8
softirqs last disabled at (210993): [<ffffffc080010288>] __do_softirq+0x18/0x20
---[ end trace 0000000000000000 ]---
lan78xx 1-1:1.0 enu1: failed to kill vid 0081/0
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-13
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:
net-shapers: don't free reply skb after genlmsg_reply()
genlmsg_reply() hands the reply skb to netlink, and
netlink_unicast() consumes it on all return paths, whether the
skb is queued successfully or freed on an error path.
net_shaper_nl_get_doit() and net_shaper_nl_cap_get_doit()
currently jump to free_msg after genlmsg_reply() fails and call
nlmsg_free(msg), which can hit the same skb twice.
Return the genlmsg_reply() error directly and keep free_msg
only for pre-reply failures.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-05-13
In the Linux kernel, the following vulnerability has been resolved:
sched_ext: Disable preemption between scx_claim_exit() and kicking helper work
scx_claim_exit() atomically sets exit_kind, which prevents scx_error() from
triggering further error handling. After claiming exit, the caller must kick
the helper kthread work which initiates bypass mode and teardown.
If the calling task gets preempted between claiming exit and kicking the
helper work, and the BPF scheduler fails to schedule it back (since error
handling is now disabled), the helper work is never queued, bypass mode
never activates, tasks stop being dispatched, and the system wedges.
Disable preemption across scx_claim_exit() and the subsequent work kicking
in all callers - scx_disable() and scx_vexit(). Add
lockdep_assert_preemption_disabled() to scx_claim_exit() to enforce the
requirement.
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