Linux: >> Linux Kernel >> 5.15.189 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ipv6: prevent possible UaF in addrconf_permanent_addr()
The mentioned helper try to warn the user about an exceptional
condition, but the message is delivered too late, accessing the ipv6
after its possible deletion.
Reorder the statement to avoid the possible UaF; while at it, place the
warning outside the idev->lock as it needs no protection.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
comedi: Reinit dev->spinlock between attachments to low-level drivers
`struct comedi_device` is the main controlling structure for a COMEDI
device created by the COMEDI subsystem. It contains a member `spinlock`
containing a spin-lock that is initialized by the COMEDI subsystem, but
is reserved for use by a low-level driver attached to the COMEDI device
(at least since commit 25436dc9d84f ("Staging: comedi: remove RT
code")).
Some COMEDI devices (those created on initialization of the COMEDI
subsystem when the "comedi.comedi_num_legacy_minors" parameter is
non-zero) can be attached to different low-level drivers over their
lifetime using the `COMEDI_DEVCONFIG` ioctl command. This can result in
inconsistent lock states being reported when there is a mismatch in the
spin-lock locking levels used by each low-level driver to which the
COMEDI device has been attached. Fix it by reinitializing
`dev->spinlock` before calling the low-level driver's `attach` function
pointer if `CONFIG_LOCKDEP` is enabled.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
USB: dummy-hcd: Fix locking/synchronization error
Syzbot testing was able to provoke an addressing exception and crash
in the usb_gadget_udc_reset() routine in
drivers/usb/gadgets/udc/core.c, resulting from the fact that the
routine was called with a second ("driver") argument of NULL. The bad
caller was set_link_state() in dummy_hcd.c, and the problem arose
because of a race between a USB reset and driver unbind.
These sorts of races were not supposed to be possible; commit
7dbd8f4cabd9 ("USB: dummy-hcd: Fix erroneous synchronization change"),
along with a few followup commits, was written specifically to prevent
them. As it turns out, there are (at least) two errors remaining in
the code. Another patch will address the second error; this one is
concerned with the first.
The error responsible for the syzbot crash occurred because the
stop_activity() routine will sometimes drop and then re-acquire the
dum->lock spinlock. A call to stop_activity() occurs in
set_link_state() when handling an emulated USB reset, after the test
of dum->ints_enabled and before the increment of dum->callback_usage.
This allowed another thread (doing a driver unbind) to sneak in and
grab the spinlock, and then clear dum->ints_enabled and dum->driver.
Normally this other thread would have to wait for dum->callback_usage
to go down to 0 before it would clear dum->driver, but in this case it
didn't have to wait since dum->callback_usage had not yet been
incremented.
The fix is to increment dum->callback_usage _before_ calling
stop_activity() instead of after. Then the thread doing the unbind
will not clear dum->driver until after the call to
usb_gadget_udc_reset() safely returns and dum->callback_usage has been
decremented again.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: governor: fix double free in cpufreq_dbs_governor_init() error path
When kobject_init_and_add() fails, cpufreq_dbs_governor_init() calls
kobject_put(&dbs_data->attr_set.kobj).
The kobject release callback cpufreq_dbs_data_release() calls
gov->exit(dbs_data) and kfree(dbs_data), but the current error path
then calls gov->exit(dbs_data) and kfree(dbs_data) again, causing a
double free.
Keep the direct kfree(dbs_data) for the gov->init() failure path, but
after kobject_init_and_add() has been called, let kobject_put() handle
the cleanup through cpufreq_dbs_data_release().
CVSS Score
7.8
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
netfilter: flowtable: strictly check for maximum number of actions
The maximum number of flowtable hardware offload actions in IPv6 is:
* ethernet mangling (4 payload actions, 2 for each ethernet address)
* SNAT (4 payload actions)
* DNAT (4 payload actions)
* Double VLAN (4 vlan actions, 2 for popping vlan, and 2 for pushing)
for QinQ.
* Redirect (1 action)
Which makes 17, while the maximum is 16. But act_ct supports for tunnels
actions too. Note that payload action operates at 32-bit word level, so
mangling an IPv6 address takes 4 payload actions.
Update flow_action_entry_next() calls to check for the maximum number of
supported actions.
While at it, rise the maximum number of actions per flow from 16 to 24
so this works fine with IPv6 setups.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
USB: dummy-hcd: Fix interrupt synchronization error
This fixes an error in synchronization in the dummy-hcd driver. The
error has a somewhat involved history. The synchronization mechanism
was introduced by commit 7dbd8f4cabd9 ("USB: dummy-hcd: Fix erroneous
synchronization change"), which added an emulated "interrupts enabled"
flag together with code emulating synchronize_irq() (it waits until
all current handler callbacks have returned).
But the emulated interrupt-disable occurred too late, after the driver
containing the handler callback routines had been told that it was
unbound and no more callbacks would occur. Commit 4a5d797a9f9c ("usb:
gadget: dummy_hcd: fix gpf in gadget_setup") tried to fix this by
moving the synchronize_irq() emulation code from dummy_stop() to
dummy_pullup(), which runs before the unbind callback.
There still were races, though, because the emulated interrupt-disable
still occurred too late. It couldn't be moved to dummy_pullup(),
because that routine can be called for reasons other than an impending
unbind. Therefore commits 7dc0c55e9f30 ("USB: UDC core: Add
udc_async_callbacks gadget op") and 04145a03db9d ("USB: UDC: Implement
udc_async_callbacks in dummy-hcd") added an API allowing the UDC core
to tell dummy-hcd exactly when emulated interrupts and their callbacks
should be disabled.
That brings us to the current state of things, which is still wrong
because the emulated synchronize_irq() occurs before the emulated
interrupt-disable! That's no good, beause it means that more emulated
interrupts can occur after the synchronize_irq() emulation has run,
leading to the possibility that a callback handler may be running when
the gadget driver is unbound.
To fix this, we have to move the synchronize_irq() emulation code yet
again, to the dummy_udc_async_callbacks() routine, which takes care of
enabling and disabling emulated interrupt requests. The
synchronization will now run immediately after emulated interrupts are
disabled, which is where it belongs.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
media: solo6x10: Check for out of bounds chip_id
Clang with CONFIG_UBSAN_SHIFT=y noticed a condition where a signed type
(literal "1" is an "int") could end up being shifted beyond 32 bits,
so instrumentation was added (and due to the double is_tw286x() call
seen via inlining), Clang decides the second one must now be undefined
behavior and elides the rest of the function[1]. This is a known problem
with Clang (that is still being worked on), but we can avoid the entire
problem by actually checking the existing max chip ID, and now there is
no runtime instrumentation added at all since everything is known to be
within bounds.
Additionally use an unsigned value for the shift to remove the
instrumentation even without the explicit bounds checking.
[hverkuil: fix checkpatch warning for is_tw286x]
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
most: core: fix leak on early registration failure
A recent commit fixed a resource leak on early registration failures but
for some reason left out the first error path which still leaks the
resources associated with the interface.
Fix up also the first error path so that the interface is always
released on errors.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix sync handling in amdgpu_dma_buf_move_notify
Invalidating a dmabuf will impact other users of the shared BO.
In the scenario where process A moves the BO, it needs to inform
process B about the move and process B will need to update its
page table.
The commit fixes a synchronisation bug caused by the use of the
ticket: it made amdgpu_vm_handle_moved behave as if updating
the page table immediately was correct but in this case it's not.
An example is the following scenario, with 2 GPUs and glxgears
running on GPU0 and Xorg running on GPU1, on a system where P2P
PCI isn't supported:
glxgears:
export linear buffer from GPU0 and import using GPU1
submit frame rendering to GPU0
submit tiled->linear blit
Xorg:
copy of linear buffer
The sequence of jobs would be:
drm_sched_job_run # GPU0, frame rendering
drm_sched_job_queue # GPU0, blit
drm_sched_job_done # GPU0, frame rendering
drm_sched_job_run # GPU0, blit
move linear buffer for GPU1 access #
amdgpu_dma_buf_move_notify -> update pt # GPU0
It this point the blit job on GPU0 is still running and would
likely produce a page fault.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
media: i2c: ov5647: Initialize subdev before controls
In ov5647_init_controls() we call v4l2_get_subdevdata, but it is
initialized by v4l2_i2c_subdev_init() in the probe, which currently
happens after init_controls(). This can result in a segfault if the
error condition is hit, and we try to access i2c_client, so fix the
order.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08