Linux: >> Linux Kernel >> 4.20.2 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
net/x25: Fix potential double free of skb
When alloc_skb fails in x25_queue_rx_frame it calls kfree_skb(skb) at
line 48 and returns 1 (error).
This error propagates back through the call chain:
x25_queue_rx_frame returns 1
|
v
x25_state3_machine receives the return value 1 and takes the else
branch at line 278, setting queued=0 and returning 0
|
v
x25_process_rx_frame returns queued=0
|
v
x25_backlog_rcv at line 452 sees queued=0 and calls kfree_skb(skb)
again
This would free the same skb twice. Looking at x25_backlog_rcv:
net/x25/x25_in.c:x25_backlog_rcv() {
...
queued = x25_process_rx_frame(sk, skb);
...
if (!queued)
kfree_skb(skb);
}
CVSS Score
9.8
EPSS Score
0.001
Published
2026-05-01
In the Linux kernel, the following vulnerability has been resolved:
ALSA: ctxfi: Check the error for index mapping
The ctxfi driver blindly assumed a proper value returned from
daio_device_index(), but it's not always true. Add a proper error
check to deal with the error from the function.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-01
In the Linux kernel, the following vulnerability has been resolved:
ALSA: caiaq: fix stack out-of-bounds read in init_card
The loop creates a whitespace-stripped copy of the card shortname
where `len < sizeof(card->id)` is used for the bounds check. Since
sizeof(card->id) is 16 and the local id buffer is also 16 bytes,
writing 16 non-space characters fills the entire buffer,
overwriting the terminating nullbyte.
When this non-null-terminated string is later passed to
snd_card_set_id() -> copy_valid_id_string(), the function scans
forward with `while (*nid && ...)` and reads past the end of the
stack buffer, reading the contents of the stack.
A USB device with a product name containing many non-ASCII, non-space
characters (e.g. multibyte UTF-8) will reliably trigger this as follows:
BUG: KASAN: stack-out-of-bounds in copy_valid_id_string
sound/core/init.c:696 [inline]
BUG: KASAN: stack-out-of-bounds in snd_card_set_id_no_lock+0x698/0x74c
sound/core/init.c:718
The off-by-one has been present since commit bafeee5b1f8d ("ALSA:
snd_usb_caiaq: give better shortname") from June 2009 (v2.6.31-rc1),
which first introduced this whitespace-stripping loop. The original
code never accounted for the null terminator when bounding the copy.
Fix this by changing the loop bound to `sizeof(card->id) - 1`,
ensuring at least one byte remains as the null terminator.
CVSS Score
7.1
EPSS Score
0.0
Published
2026-05-01
In the Linux kernel, the following vulnerability has been resolved:
wifi: wilc1000: fix u8 overflow in SSID scan buffer size calculation
The variable valuesize is declared as u8 but accumulates the total
length of all SSIDs to scan. Each SSID contributes up to 33 bytes
(IEEE80211_MAX_SSID_LEN + 1), and with WILC_MAX_NUM_PROBED_SSID (10)
SSIDs the total can reach 330, which wraps around to 74 when stored
in a u8.
This causes kmalloc to allocate only 75 bytes while the subsequent
memcpy writes up to 331 bytes into the buffer, resulting in a 256-byte
heap buffer overflow.
Widen valuesize from u8 to u32 to accommodate the full range.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-05-01
In the Linux kernel, the following vulnerability has been resolved:
drm/ioc32: stop speculation on the drm_compat_ioctl path
The drm compat ioctl path takes a user controlled pointer, and then
dereferences it into a table of function pointers, the signature method
of spectre problems. Fix this up by calling array_index_nospec() on the
index to the function pointer list.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-01
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: SMP: derive legacy responder STK authentication from MITM state
The legacy responder path in smp_random() currently labels the stored
STK as authenticated whenever pending_sec_level is BT_SECURITY_HIGH.
That reflects what the local service requested, not what the pairing
flow actually achieved.
For Just Works/Confirm legacy pairing, SMP_FLAG_MITM_AUTH stays clear
and the resulting STK should remain unauthenticated even if the local
side requested HIGH security. Use the established MITM state when
storing the responder STK so the key metadata matches the pairing result.
This also keeps the legacy path aligned with the Secure Connections code,
which already treats JUST_WORKS/JUST_CFM as unauthenticated.
CVSS Score
8.8
EPSS Score
0.001
Published
2026-05-01
In the Linux kernel, the following vulnerability has been resolved:
iio: gyro: mpu3050: Move iio_device_register() to correct location
iio_device_register() should be at the end of the probe function to
prevent race conditions.
Place iio_device_register() at the end of the probe function and place
iio_device_unregister() accordingly.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-05-01
In the Linux kernel, the following vulnerability has been resolved:
iio: gyro: mpu3050: Fix irq resource leak
The interrupt handler is setup but only a few lines down if
iio_trigger_register() fails the function returns without properly
releasing the handler.
Add cleanup goto to resolve resource leak.
Detected by Smatch:
drivers/iio/gyro/mpu3050-core.c:1128 mpu3050_trigger_probe() warn:
'irq' from request_threaded_irq() not released on lines: 1124.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-01
In the Linux kernel, the following vulnerability has been resolved:
iio: gyro: mpu3050: Fix incorrect free_irq() variable
The handler for the IRQ part of this driver is mpu3050->trig but,
in the teardown free_irq() is called with handler mpu3050.
Use correct IRQ handler when calling free_irq().
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-01
In the Linux kernel, the following vulnerability has been resolved:
iio: adc: ti-adc161s626: use DMA-safe memory for spi_read()
Add a DMA-safe buffer and use it for spi_read() instead of a stack
memory. All SPI buffers must be DMA-safe.
Since we only need up to 3 bytes, we just use a u8[] instead of __be16
and __be32 and change the conversion functions appropriately.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-05-01