Linux: >> Linux Kernel >> 4.12.1 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
NFC: digital: Bounds check NFC-A cascade depth in SDD response handler
The NFC-A anti-collision cascade in digital_in_recv_sdd_res() appends 3
or 4 bytes to target->nfcid1 on each round, but the number of cascade
rounds is controlled entirely by the peer device. The peer sets the
cascade tag in the SDD_RES (deciding 3 vs 4 bytes) and the
cascade-incomplete bit in the SEL_RES (deciding whether another round
follows).
ISO 14443-3 limits NFC-A to three cascade levels and target->nfcid1 is
sized accordingly (NFC_NFCID1_MAXSIZE = 10), but nothing in the driver
actually enforces this. This means a malicious peer can keep the
cascade running, writing past the heap-allocated nfc_target with each
round.
Fix this by rejecting the response when the accumulated UID would exceed
the buffer.
Commit e329e71013c9 ("NFC: nci: Bounds check struct nfc_target arrays")
fixed similar missing checks against the same field on the NCI path.
CVSS Score
8.8
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()
A malicious USB device claiming to be a CDC Phonet modem can overflow
the skb_shared_info->frags[] array by sending an unbounded sequence of
full-page bulk transfers.
Drop the skb and increment the length error when the frag limit is
reached. This matches the same fix that commit f0813bcd2d9d ("net:
wwan: t7xx: fix potential skb->frags overflow in RX path") did for the
t7xx driver.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
HID: core: clamp report_size in s32ton() to avoid undefined shift
s32ton() shifts by n-1 where n is the field's report_size, a value that
comes directly from a HID device. The HID parser bounds report_size
only to <= 256, so a broken HID device can supply a report descriptor
with a wide field that triggers shift exponents up to 256 on a 32-bit
type when an output report is built via hid_output_field() or
hid_set_field().
Commit ec61b41918587 ("HID: core: fix shift-out-of-bounds in
hid_report_raw_event") added the same n > 32 clamp to the function
snto32(), but s32ton() was never given the same fix as I guess syzbot
hadn't figured out how to fuzz a device the same way.
Fix this up by just clamping the max value of n, just like snto32()
does.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: initialize le_tmp64 in rtw_BIP_verify()
Initialize le_tmp64 to zero in rtw_BIP_verify() to prevent using
uninitialized data.
Smatch warns that only 6 bytes are copied to this 8-byte (u64)
variable, leaving the last two bytes uninitialized:
drivers/staging/rtl8723bs/core/rtw_security.c:1308 rtw_BIP_verify()
warn: not copying enough bytes for '&le_tmp64' (8 vs 6 bytes)
Initializing the variable at the start of the function fixes this
warning and ensures predictable behavior.
CVSS Score
7.1
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
smb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list()
smb_direct_flush_send_list() already calls smb_direct_free_sendmsg(),
so we should not call it again after post_sendmsg()
moved it to the batch list.
CVSS Score
9.8
EPSS Score
0.001
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
smb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush()
smbd_send_batch_flush() already calls smbd_free_send_io(),
so we should not call it again after smbd_post_send()
moved it to the batch list.
CVSS Score
9.8
EPSS Score
0.001
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: renesas_usb3: validate endpoint index in standard request handlers
The GET_STATUS and SET/CLEAR_FEATURE handlers extract the endpoint
number from the host-supplied wIndex without any sort of validation.
Fix this up by validating the number of endpoints actually match up with
the number the device has before attempting to dereference a pointer
based on this math.
This is just like what was done in commit ee0d382feb44 ("usb: gadget:
aspeed_udc: validate endpoint index for ast udc") for the aspeed driver.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_phonet: fix skb frags[] overflow in pn_rx_complete()
A broken/bored/mean USB host can overflow the skb_shared_info->frags[]
array on a Linux gadget exposing a Phonet function by sending an
unbounded sequence of full-page OUT transfers.
pn_rx_complete() finalizes the skb only when req->actual < req->length,
where req->length is set to PAGE_SIZE by the gadget. If the host always
sends exactly PAGE_SIZE bytes per transfer, fp->rx.skb will never be
reset and each completion will add another fragment via
skb_add_rx_frag(). Once nr_frags exceeds MAX_SKB_FRAGS (default 17),
subsequent frag stores overwrite memory adjacent to the shinfo on the
heap.
Drop the skb and account a length error when the frag limit is reached,
matching the fix applied in t7xx by commit f0813bcd2d9d ("net: wwan:
t7xx: fix potential skb->frags overflow in RX path").
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
ALSA: ctxfi: Limit PTP to a single page
Commit 391e69143d0a increased CT_PTP_NUM from 1 to 4 to support 256
playback streams, but the additional pages are not used by the card
correctly. The CT20K2 hardware already has multiple VMEM_PTPAL
registers, but using them separately would require refactoring the
entire virtual memory allocation logic.
ct_vm_map() always uses PTEs in vm->ptp[0].area regardless of
CT_PTP_NUM. On AMD64 systems, a single PTP covers 512 PTEs (2M). When
aggregate memory allocations exceed this limit, ct_vm_map() tries to
access beyond the allocated space and causes a page fault:
BUG: unable to handle page fault for address: ffffd4ae8a10a000
Oops: Oops: 0002 [#1] SMP PTI
RIP: 0010:ct_vm_map+0x17c/0x280 [snd_ctxfi]
Call Trace:
atc_pcm_playback_prepare+0x225/0x3b0
ct_pcm_playback_prepare+0x38/0x60
snd_pcm_do_prepare+0x2f/0x50
snd_pcm_action_single+0x36/0x90
snd_pcm_action_nonatomic+0xbf/0xd0
snd_pcm_ioctl+0x28/0x40
__x64_sys_ioctl+0x97/0xe0
do_syscall_64+0x81/0x610
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Revert CT_PTP_NUM to 1. The 256 SRC_RESOURCE_NUM and playback_count
remain unchanged.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
staging: sm750fb: fix division by zero in ps_to_hz()
ps_to_hz() is called from hw_sm750_crtc_set_mode() without validating
that pixclock is non-zero. A zero pixclock passed via FBIOPUT_VSCREENINFO
causes a division by zero.
Fix by rejecting zero pixclock in lynxfb_ops_check_var(), consistent
with other framebuffer drivers.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-24