Linux: >> Linux Kernel >> 4.20.5 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
nfc: nci: complete pending data exchange on device close
In nci_close_device(), complete any pending data exchange before
closing. The data exchange callback (e.g.
rawsock_data_exchange_complete) holds a socket reference.
NIPA occasionally hits this leak:
unreferenced object 0xff1100000f435000 (size 2048):
comm "nci_dev", pid 3954, jiffies 4295441245
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
27 00 01 40 00 00 00 00 00 00 00 00 00 00 00 00 '..@............
backtrace (crc ec2b3c5):
__kmalloc_noprof+0x4db/0x730
sk_prot_alloc.isra.0+0xe4/0x1d0
sk_alloc+0x36/0x760
rawsock_create+0xd1/0x540
nfc_sock_create+0x11f/0x280
__sock_create+0x22d/0x630
__sys_socket+0x115/0x1d0
__x64_sys_socket+0x72/0xd0
do_syscall_64+0x117/0xfc0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-25
In the Linux kernel, the following vulnerability has been resolved:
net: usb: kaweth: validate USB endpoints
The kaweth driver should validate that the device it is probing has the
proper number and types of USB endpoints it is expecting before it binds
to it. If a malicious device were to not have the same urbs the driver
will crash later on when it blindly accesses these endpoints.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-25
In the Linux kernel, the following vulnerability has been resolved:
smb: client: Don't log plaintext credentials in cifs_set_cifscreds
When debug logging is enabled, cifs_set_cifscreds() logs the key
payload and exposes the plaintext username and password. Remove the
debug log to avoid exposing credentials.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-25
In the Linux kernel, the following vulnerability has been resolved:
ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu()
l3mdev_master_dev_rcu() can return NULL when the slave device is being
un-slaved from a VRF. All other callers deal with this, but we lost
the fallback to loopback in ip6_rt_pcpu_alloc() -> ip6_rt_get_dev_rcu()
with commit 4832c30d5458 ("net: ipv6: put host and anycast routes on
device with address").
KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f]
RIP: 0010:ip6_rt_pcpu_alloc (net/ipv6/route.c:1418)
Call Trace:
ip6_pol_route (net/ipv6/route.c:2318)
fib6_rule_lookup (net/ipv6/fib6_rules.c:115)
ip6_route_output_flags (net/ipv6/route.c:2607)
vrf_process_v6_outbound (drivers/net/vrf.c:437)
I was tempted to rework the un-slaving code to clear the flag first
and insert synchronize_rcu() before we remove the upper. But looks like
the explicit fallback to loopback_dev is an established pattern.
And I guess avoiding the synchronize_rcu() is nice, too.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-25
In the Linux kernel, the following vulnerability has been resolved:
can: ems_usb: ems_usb_read_bulk_callback(): check the proper length of a message
When looking at the data in a USB urb, the actual_length is the size of
the buffer passed to the driver, not the transfer_buffer_length which is
set by the driver as the max size of the buffer.
When parsing the messages in ems_usb_read_bulk_callback() properly check
the size both at the beginning of parsing the message to make sure it is
big enough for the expected structure, and at the end of the message to
make sure we don't overflow past the end of the buffer for the next
message.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-25
In the Linux kernel, the following vulnerability has been resolved:
can: ucan: Fix infinite loop from zero-length messages
If a broken ucan device gets a message with the message length field set
to 0, then the driver will loop for forever in
ucan_read_bulk_callback(), hanging the system. If the length is 0, just
skip the message and go on to the next one.
This has been fixed in the kvaser_usb driver in the past in commit
0c73772cd2b8 ("can: kvaser_usb: leaf: Fix potential infinite loop in
command parsers"), so there must be some broken devices out there like
this somewhere.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-25
In the Linux kernel, the following vulnerability has been resolved:
net: annotate data-races around sk->sk_{data_ready,write_space}
skmsg (and probably other layers) are changing these pointers
while other cpus might read them concurrently.
Add corresponding READ_ONCE()/WRITE_ONCE() annotations
for UDP, TCP and AF_UNIX.
CVSS Score
4.7
EPSS Score
0.0
Published
2026-03-25
In the Linux kernel, the following vulnerability has been resolved:
net: usb: pegasus: validate USB endpoints
The pegasus driver should validate that the device it is probing has the
proper number and types of USB endpoints it is expecting before it binds
to it. If a malicious device were to not have the same urbs the driver
will crash later on when it blindly accesses these endpoints.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-25
In the Linux kernel, the following vulnerability has been resolved:
nfc: pn533: properly drop the usb interface reference on disconnect
When the device is disconnected from the driver, there is a "dangling"
reference count on the usb interface that was grabbed in the probe
callback. Fix this up by properly dropping the reference after we are
done with it.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-25
In the Linux kernel, the following vulnerability has been resolved:
net: vxlan: fix nd_tbl NULL dereference when IPv6 is disabled
When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never
initialized because inet6_init() exits before ndisc_init() is called
which initializes it. If an IPv6 packet is injected into the interface,
route_shortcircuit() is called and a NULL pointer dereference happens on
neigh_lookup().
BUG: kernel NULL pointer dereference, address: 0000000000000380
Oops: Oops: 0000 [#1] SMP NOPTI
[...]
RIP: 0010:neigh_lookup+0x20/0x270
[...]
Call Trace:
<TASK>
vxlan_xmit+0x638/0x1ef0 [vxlan]
dev_hard_start_xmit+0x9e/0x2e0
__dev_queue_xmit+0xbee/0x14e0
packet_sendmsg+0x116f/0x1930
__sys_sendto+0x1f5/0x200
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x12f/0x1590
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Fix this by adding an early check on route_shortcircuit() when protocol
is ETH_P_IPV6. Note that ipv6_mod_enabled() cannot be used here because
VXLAN can be built-in even when IPv6 is built as a module.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-03-25