Linux: >> Linux Kernel >> 6.6.48 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
can: ucan: fix out of bound read in strscpy() source
Commit 7fdaf8966aae ("can: ucan: use strscpy() to instead of strncpy()")
unintentionally introduced a one byte out of bound read on strscpy()'s
source argument (which is kind of ironic knowing that strscpy() is meant
to be a more secure alternative :)).
Let's consider below buffers:
dest[len + 1]; /* will be NUL terminated */
src[len]; /* may not be NUL terminated */
When doing:
strncpy(dest, src, len);
dest[len] = '\0';
strncpy() will read up to len bytes from src.
On the other hand:
strscpy(dest, src, len + 1);
will read up to len + 1 bytes from src, that is to say, an out of bound
read of one byte will occur on src if it is not NUL terminated. Note
that the src[len] byte is never copied, but strscpy() still needs to
read it to check whether a truncation occurred or not.
This exact pattern happened in ucan.
The root cause is that the source is not NUL terminated. Instead of
doing a copy in a local buffer, directly NUL terminate it as soon as
usb_control_msg() returns. With this, the local firmware_str[] variable
can be removed.
On top of this do a couple refactors:
- ucan_ctl_payload->raw is only used for the firmware string, so
rename it to ucan_ctl_payload->fw_str and change its type from u8 to
char.
- ucan_device_request_in() is only used to retrieve the firmware
string, so rename it to ucan_get_fw_str() and refactor it to make it
directly handle all the string termination logic.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-03
In the Linux kernel, the following vulnerability has been resolved:
net: atm: fix use after free in lec_send()
The ->send() operation frees skb so save the length before calling
->send() to avoid a use after free.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-04-03
In the Linux kernel, the following vulnerability has been resolved:
drm/sched: Fix fence reference count leak
The last_scheduled fence leaks when an entity is being killed and adding
the cleanup callback fails.
Decrement the reference count of prev when dma_fence_add_callback()
fails, ensuring proper balance.
[phasta: add git tag info for stable kernel]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-03
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix incorrect validation for num_aces field of smb_acl
parse_dcal() validate num_aces to allocate posix_ace_state_array.
if (num_aces > ULONG_MAX / sizeof(struct smb_ace *))
It is an incorrect validation that we can create an array of size ULONG_MAX.
smb_acl has ->size field to calculate actual number of aces in request buffer
size. Use this to check invalid num_aces.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-02
In the Linux kernel, the following vulnerability has been resolved:
x86/microcode/AMD: Fix out-of-bounds on systems with CPU-less NUMA nodes
Currently, load_microcode_amd() iterates over all NUMA nodes, retrieves their
CPU masks and unconditionally accesses per-CPU data for the first CPU of each
mask.
According to Documentation/admin-guide/mm/numaperf.rst:
"Some memory may share the same node as a CPU, and others are provided as
memory only nodes."
Therefore, some node CPU masks may be empty and wouldn't have a "first CPU".
On a machine with far memory (and therefore CPU-less NUMA nodes):
- cpumask_of_node(nid) is 0
- cpumask_first(0) is CONFIG_NR_CPUS
- cpu_data(CONFIG_NR_CPUS) accesses the cpu_info per-CPU array at an
index that is 1 out of bounds
This does not have any security implications since flashing microcode is
a privileged operation but I believe this has reliability implications by
potentially corrupting memory while flashing a microcode update.
When booting with CONFIG_UBSAN_BOUNDS=y on an AMD machine that flashes
a microcode update. I get the following splat:
UBSAN: array-index-out-of-bounds in arch/x86/kernel/cpu/microcode/amd.c:X:Y
index 512 is out of range for type 'unsigned long[512]'
[...]
Call Trace:
dump_stack
__ubsan_handle_out_of_bounds
load_microcode_amd
request_microcode_amd
reload_store
kernfs_fop_write_iter
vfs_write
ksys_write
do_syscall_64
entry_SYSCALL_64_after_hwframe
Change the loop to go over only NUMA nodes which have CPUs before determining
whether the first CPU on the respective node needs microcode update.
[ bp: Massage commit message, fix typo. ]
CVSS Score
7.8
EPSS Score
0.0
Published
2025-04-02
In the Linux kernel, the following vulnerability has been resolved:
HID: ignore non-functional sensor in HP 5MP Camera
The HP 5MP Camera (USB ID 0408:5473) reports a HID sensor interface that
is not actually implemented. Attempting to access this non-functional
sensor via iio_info causes system hangs as runtime PM tries to wake up
an unresponsive sensor.
[453] hid-sensor-hub 0003:0408:5473.0003: Report latency attributes: ffffffff:ffffffff
[453] hid-sensor-hub 0003:0408:5473.0003: common attributes: 5:1, 2:1, 3:1 ffffffff:ffffffff
Add this device to the HID ignore list since the sensor interface is
non-functional by design and should not be exposed to userspace.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-02
In the Linux kernel, the following vulnerability has been resolved:
iscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic()
When performing an iSCSI boot using IPv6, iscsistart still reads the
/sys/firmware/ibft/ethernetX/subnet-mask entry. Since the IPv6 prefix
length is 64, this causes the shift exponent to become negative,
triggering a UBSAN warning. As the concept of a subnet mask does not
apply to IPv6, the value is set to ~0 to suppress the warning message.
CVSS Score
7.1
EPSS Score
0.0
Published
2025-04-02
In the Linux kernel, the following vulnerability has been resolved:
net: switchdev: Convert blocking notification chain to a raw one
A blocking notification chain uses a read-write semaphore to protect the
integrity of the chain. The semaphore is acquired for writing when
adding / removing notifiers to / from the chain and acquired for reading
when traversing the chain and informing notifiers about an event.
In case of the blocking switchdev notification chain, recursive
notifications are possible which leads to the semaphore being acquired
twice for reading and to lockdep warnings being generated [1].
Specifically, this can happen when the bridge driver processes a
SWITCHDEV_BRPORT_UNOFFLOADED event which causes it to emit notifications
about deferred events when calling switchdev_deferred_process().
Fix this by converting the notification chain to a raw notification
chain in a similar fashion to the netdev notification chain. Protect
the chain using the RTNL mutex by acquiring it when modifying the chain.
Events are always informed under the RTNL mutex, but add an assertion in
call_switchdev_blocking_notifiers() to make sure this is not violated in
the future.
Maintain the "blocking" prefix as events are always emitted from process
context and listeners are allowed to block.
[1]:
WARNING: possible recursive locking detected
6.14.0-rc4-custom-g079270089484 #1 Not tainted
--------------------------------------------
ip/52731 is trying to acquire lock:
ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0
but task is already holding lock:
ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock((switchdev_blocking_notif_chain).rwsem);
lock((switchdev_blocking_notif_chain).rwsem);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by ip/52731:
#0: ffffffff84f795b0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x727/0x1dc0
#1: ffffffff8731f628 (&net->rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x790/0x1dc0
#2: ffffffff850918d8 ((switchdev_blocking_notif_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x58/0xa0
stack backtrace:
...
? __pfx_down_read+0x10/0x10
? __pfx_mark_lock+0x10/0x10
? __pfx_switchdev_port_attr_set_deferred+0x10/0x10
blocking_notifier_call_chain+0x58/0xa0
switchdev_port_attr_notify.constprop.0+0xb3/0x1b0
? __pfx_switchdev_port_attr_notify.constprop.0+0x10/0x10
? mark_held_locks+0x94/0xe0
? switchdev_deferred_process+0x11a/0x340
switchdev_port_attr_set_deferred+0x27/0xd0
switchdev_deferred_process+0x164/0x340
br_switchdev_port_unoffload+0xc8/0x100 [bridge]
br_switchdev_blocking_event+0x29f/0x580 [bridge]
notifier_call_chain+0xa2/0x440
blocking_notifier_call_chain+0x6e/0xa0
switchdev_bridge_port_unoffload+0xde/0x1a0
...
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-01
In the Linux kernel, the following vulnerability has been resolved:
drm/hyperv: Fix address space leak when Hyper-V DRM device is removed
When a Hyper-V DRM device is probed, the driver allocates MMIO space for
the vram, and maps it cacheable. If the device removed, or in the error
path for device probing, the MMIO space is released but no unmap is done.
Consequently the kernel address space for the mapping is leaked.
Fix this by adding iounmap() calls in the device removal path, and in the
error path during device probing.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-01
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: cancel wiphy_work before freeing wiphy
A wiphy_work can be queued from the moment the wiphy is allocated and
initialized (i.e. wiphy_new_nm). When a wiphy_work is queued, the
rdev::wiphy_work is getting queued.
If wiphy_free is called before the rdev::wiphy_work had a chance to run,
the wiphy memory will be freed, and then when it eventally gets to run
it'll use invalid memory.
Fix this by canceling the work before freeing the wiphy.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-04-01