Linux: >> Linux Kernel >> 4.9.38 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:
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: 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
In the Linux kernel, the following vulnerability has been resolved:
usb: ulpi: fix double free in ulpi_register_interface() error path
When device_register() fails, ulpi_register() calls put_device() on
ulpi->dev.
The device release callback ulpi_dev_release() drops the OF node
reference and frees ulpi, but the current error path in
ulpi_register_interface() then calls kfree(ulpi) again, causing a
double free.
Let put_device() handle the cleanup through ulpi_dev_release() and
avoid freeing ulpi again in ulpi_register_interface().
CVSS Score
7.8
EPSS Score
0.0
Published
2026-05-01
In the Linux kernel, the following vulnerability has been resolved:
comedi: me4000: Fix potential overrun of firmware buffer
`me4000_xilinx_download()` loads the firmware that was requested by
`request_firmware()`. It is possible for it to overrun the source
buffer because it blindly trusts the file format. It reads a data
stream length from the first 4 bytes into variable `file_length` and
reads the data stream contents of length `file_length` from offset 16
onwards.
Add a test to ensure that the supplied firmware is long enough to
contain the header and the data stream. On failure, log an error and
return `-EINVAL`.
Note: The firmware loading was totally broken before commit ac584af59945
("staging: comedi: me4000: fix firmware downloading"), but that is the
most sensible target for this fix.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-05-01
In the Linux kernel, the following vulnerability has been resolved:
comedi: me_daq: Fix potential overrun of firmware buffer
`me2600_xilinx_download()` loads the firmware that was requested by
`request_firmware()`. It is possible for it to overrun the source
buffer because it blindly trusts the file format. It reads a data
stream length from the first 4 bytes into variable `file_length` and
reads the data stream contents of length `file_length` from offset 16
onwards. Although it checks that the supplied firmware is at least 16
bytes long, it does not check that it is long enough to contain the data
stream.
Add a test to ensure that the supplied firmware is long enough to
contain the header and the data stream. On failure, log an error and
return `-EINVAL`.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-05-01
In the Linux kernel, the following vulnerability has been resolved:
comedi: ni_atmio16d: Fix invalid clean-up after failed attach
If the driver's COMEDI "attach" handler function (`atmio16d_attach()`)
returns an error, the COMEDI core will call the driver's "detach"
handler function (`atmio16d_detach()`) to clean up. This calls
`reset_atmio16d()` unconditionally, but depending on where the error
occurred in the attach handler, the device may not have been
sufficiently initialized to call `reset_atmio16d()`. It uses
`dev->iobase` as the I/O port base address and `dev->private` as the
pointer to the COMEDI device's private data structure. `dev->iobase`
may still be set to its initial value of 0, which would result in
undesired writes to low I/O port addresses. `dev->private` may still be
`NULL`, which would result in null pointer dereferences.
Fix `atmio16d_detach()` by checking that `dev->private` is valid
(non-null) before calling `reset_atmio16d()`. This implies that
`dev->iobase` was set correctly since that is set up before
`dev->private`.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-01