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Published vulnerabilities with severity, known exploitation and official sources.
CVE-2026-64304
High · 7.8
CWE-787 Jul 25, 2026
crypto: qat - validate RSA CRT component lengths
In the Linux kernel, the following vulnerability has been resolved:
crypto: qat - validate RSA CRT component lengths
The generic RSA key parser (rsa_helper.c) bounds each CRT component (p,
q, dp, dq, qinv) by the modulus size n_sz, but qat_rsa_setkey_crt()
allocates half-size DMA buffers (key_sz / 2) and right-aligns each
component with:
memcpy(dst + half_key_sz - len, src, len)
When a CRT component is larger than half_key_sz the subtraction
underflows and memcpy writes past the DMA buffer, causing memory
corruption.
Add a len > half_key_sz check next to the existing !len check for each
of the five CRT components so the driver falls back to the non-CRT path
instead of writing out of bounds.
CVE-2026-64296
High · 7.8
CWE-787 Jul 25, 2026
exfat: bound uniname advance in exfat_find_dir_entry()
In the Linux kernel, the following vulnerability has been resolved:
exfat: bound uniname advance in exfat_find_dir_entry()
In exfat_find_dir_entry(), each TYPE_EXTEND (file name) entry advances the
output pointer by a fixed amount while the loop guard only tracks the
accumulated name length:
if (++order == 2)
uniname = p_uniname->name;
else
uniname += EXFAT_FILE_NAME_LEN;
len = exfat_extract_uni_name(ep, entry_uniname);
name_len += len;
unichar = *(uniname+len);
*(uniname+len) = 0x0;
uniname grows by EXFAT_FILE_NAME_LEN (15) per name entry, but name_len
grows only by the actual extracted length, which is shorter when a name
fragment contains an early NUL. The only guard is
`name_len >= MAX_NAME_LENGTH`, so a crafted directory with many short
name fragments lets uniname run far past the
p_uniname->name[MAX_NAME_LENGTH + 3] buffer while name_len stays small,
causing an out-of-bounds read and write at *(uniname+len).
The sibling extractor exfat_get_uniname_from_ext_entry() already stops
on a short fragment (the lockstep `len != EXFAT_FILE_NAME_LEN` guard
added in commit d42334578eba ("exfat: check if filename entries exceeds
max filename length")); exfat_find_dir_entry() never got the
equivalent. Track the per-entry write offset as a count and reject a
fragment once the offset, or the offset plus the extracted length, would
exceed MAX_NAME_LENGTH, before forming the output pointer.
CVE-2026-64293
High · 7.8
CWE-787 Jul 25, 2026
iommufd: Use sizeof(*hdr) instead of sizeof(hdr) in veventq read
In the Linux kernel, the following vulnerability has been resolved:
iommufd: Use sizeof(*hdr) instead of sizeof(hdr) in veventq read
The bound-check in iommufd_veventq_fops_read() for the normal vEVENT
path uses sizeof(hdr) where the surrounding code uses sizeof(*hdr):
if (!vevent_for_lost_events_header(cur) &&
sizeof(hdr) + cur->data_len > count - done) {
hdr is declared as struct iommufd_vevent_header *, so sizeof(hdr)
evaluates to the size of the pointer. Surrounding code uses
sizeof(*hdr) consistently:
if (done >= count || sizeof(*hdr) > count - done) {
...
if (copy_to_user(buf + done, hdr, sizeof(*hdr))) {
...
done += sizeof(*hdr);
struct iommufd_vevent_header is currently 8 bytes (two __u32 fields,
flags and sequence), so on 64-bit (sizeof(void *) == 8) the two
expressions happen to be equal and the check works as intended.
On 32-bit (sizeof(void *) == 4) the check under-counts the header by
4 bytes: a vEVENT whose data_len causes 8 + cur->data_len to exceed
count - done while 4 + cur->data_len does not will pass the check,
then the loop will copy_to_user 8 bytes of header followed by data_len
bytes of payload, writing past the user-supplied buffer.
It is also a latent bug for any future expansion of struct
iommufd_vevent_header beyond sizeof(void *) on 64-bit; the check
should not depend on the type happening to match the host pointer
width.
Use sizeof(*hdr) to match the rest of the function and the actual
amount that will be copied.
CVE-2026-64276
High · 7.8
CWE-787 Jul 25, 2026
Input: synaptics-rmi4 - bound the F30 keymap to the GPIO/LED count
In the Linux kernel, the following vulnerability has been resolved:
Input: synaptics-rmi4 - bound the F30 keymap to the GPIO/LED count
rmi_f30_map_gpios() allocates gpioled_key_map with
min(gpioled_count, TRACKSTICK_RANGE_END) == at most 6 entries, but
rmi_f30_attention() iterates the full f30->gpioled_count (device query
register, range 0..31) and dereferences gpioled_key_map[i], and
input->keycodemax is set to the full gpioled_count while input->keycode
points at the 6-entry allocation.
A device that reports gpioled_count > 6 with GPIO support enabled
therefore causes an out-of-bounds read on the attention interrupt and
out-of-bounds read/write through the EVIOCGKEYCODE/EVIOCSKEYCODE ioctls,
which bound the index only against keycodemax. This is the same defect
as the F3A handler, which was copied from F30.
Size the keymap for the full gpioled_count; the mapping loop still
assigns only the first min(gpioled_count, TRACKSTICK_RANGE_END) entries.
CVE-2026-64274
High · 7.8
CWE-787 Jul 25, 2026
Input: goodix - clamp the device-reported contact count
In the Linux kernel, the following vulnerability has been resolved:
Input: goodix - clamp the device-reported contact count
goodix_ts_read_input_report() copies the number of touch points reported
by the device into an on-stack buffer
u8 point_data[2 + GOODIX_MAX_CONTACT_SIZE * GOODIX_MAX_CONTACTS];
which is sized for at most GOODIX_MAX_CONTACTS (10) contacts. The only
runtime check bounds the per-interrupt count against ts->max_touch_num,
but that value is taken verbatim from a 4-bit field of the device
configuration block and is never clamped:
ts->max_touch_num = ts->config[MAX_CONTACTS_LOC] & 0x0f;
The nibble can be 0..15, so a malfunctioning, malicious or counterfeit
controller (or an attacker tampering with the I2C bus) can advertise up
to 15 contacts. goodix_ts_read_input_report() then accepts a touch_num
of up to 15 and the second goodix_i2c_read() writes
ts->contact_size * (touch_num - 1) bytes past the one-contact header into
point_data - up to 30 bytes (45 with the 9-byte report format) beyond the
92-byte buffer: a stack out-of-bounds write.
Clamp max_touch_num to GOODIX_MAX_CONTACTS, the number of contacts
point_data[] is sized for, when reading it from the configuration.
CVE-2026-64270
High · 7.8
CWE-787 Jul 25, 2026
Input: mms114 - reject an oversized device packet size
In the Linux kernel, the following vulnerability has been resolved:
Input: mms114 - reject an oversized device packet size
mms114_interrupt() reads a packet of touch data from the device into a
fixed-size on-stack buffer
struct mms114_touch touch[MMS114_MAX_TOUCH];
which holds MMS114_MAX_TOUCH (10) events of MMS114_EVENT_SIZE (8) bytes,
i.e. 80 bytes. The length of the I2C read into it is taken verbatim from
the device:
packet_size = mms114_read_reg(data, MMS114_PACKET_SIZE);
if (packet_size <= 0)
goto out;
...
error = __mms114_read_reg(data, MMS114_INFORMATION, packet_size,
(u8 *)touch);
packet_size is a single device register byte (0x0F) and the only check
is the lower bound packet_size <= 0; it is never bounded against the
size of touch[]. A malfunctioning, malicious or counterfeit controller
(or an attacker tampering with the I2C bus) can report a packet_size of
up to 255, so __mms114_read_reg() writes up to 175 bytes past the end of
touch[] on the IRQ-thread stack: a stack out-of-bounds write that can
overwrite the stack canary, saved registers and the return address.
A well-formed device never reports more than the buffer holds, so reject
an oversized packet and drop the report, consistent with the handler's
other error paths, rather than reading past the buffer.
CVE-2026-64268
Critical · 9.8
CWE-787 Jul 25, 2026
RDMA/siw: bound Read Response placement to the RREAD length
In the Linux kernel, the following vulnerability has been resolved:
RDMA/siw: bound Read Response placement to the RREAD length
In drivers/infiniband/sw/siw/siw_qp_rx.c, siw_proc_rresp() places each
inbound Read Response DDP segment at sge->laddr + wqe->processed and then
accumulates wqe->processed, but it never checks the running total against
the sink buffer length on continuation segments. siw_check_sge() resolves
and validates the sink memory only on the first fragment (the if (!*mem)
branch), and siw_rresp_check_ntoh() compares the cumulative length against
wqe->bytes only on the final segment (the !frx->more_ddp_segs guard).
A connected siw peer that answers an outstanding RREAD with Read Response
segments that keep the DDP Last flag clear, carrying more total payload
than the RREAD requested, drives wqe->processed past the validated sink
buffer; the next siw_rx_data() call writes out of bounds at
sge->laddr + wqe->processed. siw runs iWARP over ordinary routable TCP,
so the peer is the remote end of an established RDMA connection and needs
no local privilege.
Bound every segment before placement, exactly as siw_proc_send() and
siw_proc_write() already do for their tagged and untagged paths, and
terminate the connection with a base-or-bounds DDP error when the
Read Response would overrun the sink buffer.
This is the second receive-path length fix for this file. A separate
change rejects an MPA FPDU length that underflows the per-fragment
remainder in the header decode; that guard does not cover this case,
because here each individual segment length is self-consistent and only
the accumulated placement offset overruns the buffer.
CVE-2026-66041
High · 7.8
CWE-787 Jul 24, 2026
FFmpeg 7.0 - 8.1.2 Heap Out-of-Bounds Write via vf_quirc Filter
FFmpeg 7.0 through 8.1.2, fixed in commit 4da9812, contains a heap out-of-bounds write vulnerability in the vf_quirc filter that allows an attacker to corrupt heap memory by supplying a crafted PGS/SUP subtitle file with mismatched frame dimensions. Attackers can provide a subtitle file whose second presentation has larger dimensions than its first, causing av_image_copy_plane() to copy data exceeding the initial allocation size into the undersized libquirc grayscale image buffer, resulting in heap corruption and process crash with potential for code execution.
CVE-2026-64217
High · 7.8
CWE-787 Jul 24, 2026
netfs: Fix overrun check in netfs_extract_user_iter()
In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix overrun check in netfs_extract_user_iter()
Fix netfs_extract_user_iter() so that if iov_iter_extract_pages() overfills
pages[], then those pages don't get included in the iterator constructed at
the end of the function. If there was an overfill, memory corruption has
already happened.
CVE-2026-16807
High · 8.8
CWE-787 Jul 23, 2026
Out of bounds write in Codecs in Google Chrome prior to 150.0.7871.186 allowed a remote attacker...
Out of bounds write in Codecs in Google Chrome prior to 150.0.7871.186 allowed a remote attacker to potentially perform a sandbox escape via a crafted HTML page. (Chromium security severity: High)
CVE-2026-65703
High · 7.8
CWE-787 Jul 23, 2026
FFmpeg 2.7 - 8.1.2 Out-of-Bounds Write in TDSC Video Decoder
FFmpeg versions 2.7 through 8.1.2 contain an out-of-bounds write vulnerability in the TDSC video decoder that allows remote attackers to cause heap corruption by supplying a crafted AVI file that changes frame dimensions across TDSF frames. The tdsc_parse_tdsf() function fails to unreference the existing reference frame before calling av_frame_get_buffer(), causing tdsc_blit() and tdsc_yuv2rgb() to write attacker-controlled pixel data beyond the end of the undersized reference frame buffer, resulting in a process crash and potential code execution.
CVE-2026-64835
High · 8.8
CWE-787 Jul 22, 2026
FFmpeg 4.4 - 8.1.2 Out-of-Bounds Memory Access in ADX Audio Decoder
FFmpeg versions 4.4 through 8.1.2 contain an out-of-bounds memory access vulnerability in the ADX audio decoder within libavcodec/adxdec.c that allows attackers to trigger both out-of-bounds reads and writes by supplying a crafted ADX or AAX audio file with a mid-stream channel layout change. When AV_PKT_DATA_NEW_EXTRADATA side data is received mid-stream, the adx_decode_frame function re-parses the stream header but fails to update the internal channel state, causing subsequent decoding operations to access the prev[] state array using a stale channel count.
CVE-2026-16413
High · 8.3
CWE-787 Jul 21, 2026
Out of bounds write in ANGLE in Google Chrome prior to 150.0.7871.182 allowed a remote attacker...
Out of bounds write in ANGLE in Google Chrome prior to 150.0.7871.182 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page. (Chromium security severity: High)
CVE-2026-47178
High · 7.8
CWE-787 Jul 21, 2026
libheif has Heap Out Of Bounds Write in unci subsystem
libheif is a HEIF and AVIF file format decoder and encoder. In versions 1.19.0 through 1.21.2, a crafted HEIF file (uncompressed `unci` codec, tiled, component-interleaved, 4:2:0) triggers a heap out-of-bounds write in libheif's uncompressed tile decoder. The write overwrites the C++ vtable pointer of an adjacent `unc_decoder_component_interleave` object; the next virtual call dispatches to an attacker-chosen address. Version 1.22.0 patches the issue.
CVE-2026-15813
Medium · 6.5
CWE-787 Jul 20, 2026
Kronosnet: kronosnet: memory corruption and out-of-bounds access via malformed network packet defragmentation
A vulnerability was found in the network packet de-fragmentation engine of kronosnet (Version affected <= 1.34). The internal reassembly code does not properly validate sequence numbers of incoming payload fragments. An attacker can exploit this lack of verification by transmitting malformed packets with corrupted sequence parameters. Under specific conditions, this forces the packet processing layer to parse data outside the designated bounds of the internal memory structures, causing an out-of-bounds memory access or heap corruption. This behavior can result in sudden application crashes or system instability.
CVE-2026-64145
High · 7.8
CWE-787 Jul 19, 2026
wifi: wilc1000: fix dma_buffer leak on bus acquire failure
In the Linux kernel, the following vulnerability has been resolved:
wifi: wilc1000: fix dma_buffer leak on bus acquire failure
wilc_wlan_firmware_download() allocates dma_buffer with kmalloc() at
the top of the function and uses a 'fail:' label to free it via
kfree(dma_buffer) on error.
All later error paths correctly use 'goto fail' to route through this
cleanup. However, the early failure path after the first acquire_bus()
call uses a bare 'return ret;', which leaks dma_buffer whenever the bus
acquire fails.
Replace the early return with goto fail so the existing cleanup path
runs.
Found via a custom Coccinelle semantic patch hunting for kmalloc'd
locals leaked on early-return error paths in driver firmware-download
code.
CVE-2026-64097
High · 7.8
CWE-787 Jul 19, 2026
drm/amd/display: Validate GPIO pin LUT table size before iterating
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Validate GPIO pin LUT table size before iterating
[Why&How]
The GPIO pin table parsers in get_gpio_i2c_info() and
bios_parser_get_gpio_pin_info() derive an element count from the VBIOS
table_header.structuresize field, then iterate over gpio_pin[] entries.
However, GET_IMAGE() only validates that the table header itself fits
within the BIOS image. If the VBIOS reports a structuresize larger than
the actual mapped data, the loop reads past the end of the BIOS image,
causing an out-of-bounds read.
Fix this by calling bios_get_image() to validate that the full claimed
structuresize is accessible within the BIOS image before entering the
loop in both functions.
(cherry picked from commit ba5e95b43b773ae1bf1f66ee6b31eb774e65afe3)
CVE-2026-64085
High · 7.8
CWE-787 Jul 19, 2026
hwmon: (pmbus/adm1266) bounce blackbox records through a protocol-sized buffer
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (pmbus/adm1266) bounce blackbox records through a protocol-sized buffer
adm1266_pmbus_block_xfer() copies the device-supplied block payload
into the caller-provided buffer using the device-supplied length:
memcpy(data_r, &msgs[1].buf[1], msgs[1].buf[0]);
The helper does not know how large data_r is and trusts the device to
return at most one record's worth of bytes. adm1266_nvmem_read_blackbox()
violates that contract: it advances read_buff inside data->dev_mem in
ADM1266_BLACKBOX_SIZE (64-byte) strides while the helper is willing to
write up to ADM1266_PMBUS_BLOCK_MAX (255) bytes. A device that returns
more than 64 bytes on the trailing record (read_buff offset 1984 in
the 2048-byte dev_mem allocation) overflows dev_mem by up to 191 bytes
before the post-call
if (ret != ADM1266_BLACKBOX_SIZE)
return -EIO;
can reject the response.
Contain the fix in the caller without changing the helper signature:
read each record into a 255-byte local bounce buffer that matches the
helper's maximum output, validate the returned length, and only then
copy exactly ADM1266_BLACKBOX_SIZE bytes into the dev_mem slot.
CVE-2026-64084
High · 7.8
CWE-787 Jul 19, 2026
hwmon: (pmbus/adm1266) cap PDIO scan in get_multiple at ADM1266_PDIO_NR
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (pmbus/adm1266) cap PDIO scan in get_multiple at ADM1266_PDIO_NR
adm1266_gpio_get_multiple() iterates the PDIO portion of the
caller-supplied mask using
for_each_set_bit_from(gpio_nr, mask,
ADM1266_GPIO_NR + ADM1266_PDIO_STATUS) {
...
}
where ADM1266_PDIO_STATUS is the PMBus command code (0xE9, i.e. 233),
not the number of PDIO pins. The intended upper bound is
ADM1266_GPIO_NR + ADM1266_PDIO_NR = 25.
gpiolib hands in a mask sized for gc.ngpio (= 25 bits on this chip),
so the iteration walks find_next_bit() up to 242, reading up to 217
extra bits (a handful of unsigned-long words: four on 64-bit, seven
on 32-bit) of whatever lives past the end of the mask in the
caller's stack. Any incidental set bit in that range then drives a
set_bit(gpio_nr, bits) call that writes past the end of the
caller-supplied bits array too -- both out-of-bounds.
Substitute ADM1266_PDIO_NR for the constant so the scan stops at the
last real PDIO bit.
CVE-2026-64081
High · 8.4
CWE-787 Jul 19, 2026
firmware: arm_ffa: Validate framework notification message layout
In the Linux kernel, the following vulnerability has been resolved:
firmware: arm_ffa: Validate framework notification message layout
Framework notifications carry an indirect message in the shared RX
buffer. Validate the reported offset and size before using them, reject
zero-length payloads, and ensure that any non-header payload starts at
the UUID field rather than in the middle of the message header.
Use the validated offset and size values for both kmemdup() and the UUID
parsing path so malformed firmware data cannot drive an out-of-bounds
read or an oversized allocation.
CVE-2026-64074
High · 7.8
CWE-787 Jul 19, 2026
fs/statmount: fix slab out-of-bounds write in statmount_mnt_idmap
In the Linux kernel, the following vulnerability has been resolved:
fs/statmount: fix slab out-of-bounds write in statmount_mnt_idmap
statmount_mnt_idmap() writes one mapping with seq_printf() and then
manually advances seq->count to include the NUL separator.
If seq_printf() overflows, seq_set_overflow() sets seq->count to
seq->size. The manual seq->count++ changes this to seq->size + 1.
seq_has_overflowed() then no longer detects the overflow. The corrupted
count returns to statmount_string(), which later executes:
seq->buf[seq->count++] = '\0';
This causes a 1-byte NULL out-of-bounds write on the dynamically
allocated seq buffer.
Fix this by checking for overflow immediately after seq_printf().
CVE-2026-64063
High · 7.8
CWE-787 Jul 19, 2026
netfs: Fix streaming write being overwritten
In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix streaming write being overwritten
In order to avoid reading whilst writing, netfslib will allow "streaming
writes" in which dirty data is stored directly into folios without reading
them first. Such folios are marked dirty but may not be marked uptodate.
If a folio is entirely written by a streaming write, uptodate will be set,
otherwise it will have a netfs_folio struct attached to ->private recording
the dirty region.
In the event that a partially written streaming write page is to be
overwritten entirely by a single write(), netfs_perform_write() will try to
copy over it, but doesn't discard the netfs_folio if it succeeds; further,
it doesn't correctly handle a partial copy that overwrites some of the
dirty data.
Fix this by the following:
(1) If the folio is successfully overwritten, free the netfs_folio struct
before marking the page uptodate.
(2) If the copy to the folio partially fails, but short of the dirty data,
just ignore the copy.
(3) If the copy partially fails and overwrites some of the dirty data,
accept the copy, update the netfs_folio struct to record the new data.
If the folio is now filled, free the netfs_folio and set uptodate,
otherwise return a partial write.
Found with:
fsx -q -N 1000000 -p 10000 -o 128000 -l 600000 \
/xfstest.test/junk --replay-ops=junk.fsxops
using the following as junk.fsxops:
truncate 0x0 0 0x927c0
write 0x63fb8 0x53c8 0
copy_range 0xb704 0x19b9 0x24429 0x79380
write 0x2402b 0x144a2 0x90660 *
write 0x204d5 0x140a0 0x927c0 *
copy_range 0x1f72c 0x137d0 0x7a906 0x927c0 *
read 0x00000 0x20000 0x9157c
read 0x20000 0x20000 0x9157c
read 0x40000 0x20000 0x9157c
read 0x60000 0x20000 0x9157c
read 0x7e1a0 0xcfb9 0x9157c
on cifs with the default cache option.
It shows folio 0x24 misbehaving if the FMODE_READ check is commented out in
netfs_perform_write():
if (//(file->f_mode & FMODE_READ) ||
netfs_is_cache_enabled(ctx)) {
and no fscache. This was initially found with the generic/522 xfstest.
CVE-2026-64041
High · 7.8
CWE-787 Jul 19, 2026
ASoC: codecs: fs210x: fix possible buffer overflow
In the Linux kernel, the following vulnerability has been resolved:
ASoC: codecs: fs210x: fix possible buffer overflow
In fs210x_effect_scene_info(), a string was copied like this:
strscpy(DST, SRC, strlen(SRC) + 1);
A buffer overflow would happen if strlen(SRC) >= sizeof(DST).
Actually, strscpy() must be used this way:
strscpy(DST, SRC, sizeof(DST));
strscpy(DST, SRC); // defaults to sizeof(DST)
CVE-2026-64026
High · 7.8
CWE-787 Jul 19, 2026
rxrpc: Fix DATA decrypt vs splice() by copying data to buffer in recvmsg
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix DATA decrypt vs splice() by copying data to buffer in recvmsg
This improves the fix for CVE-2026-43500.
Fix the pagecache corruption from in-place decryption of a DATA packet
transmitted locally by splice() by getting rid of the packet sharing in the
I/O thread and unconditionally extracting the packet content into a bounce
buffer in which the buffer is decrypted. recvmsg() (or the kernel
equivalent) then copies the data from the bounce buffer to the destination
buffer. The sk_buff then remains unmodified.
This has an additional advantage in that the packet is then arranged in the
buffer with the correct alignment required for the crypto algorithms to
process directly. The performance of the crypto does seem to be a little
faster and, surprisingly, the unencrypted performance doesn't seem to
change much - possibly due to removing complexity from the I/O thread.
Yet another advantage is that the I/O thread doesn't have to copy packets
which would slow down packet distribution, ACK generation, etc..
The buffer belongs to the call and is allocated initially at 2K,
sufficiently large to hold a whole jumbo subpacket, but the buffer will be
increased in size if needed. However, to take this work, MSG_PEEK may
cause a later packet to be decrypted into the buffer, in which case the
earlier one will need re-decrypting for a subsequent recvmsg().
Note that rx_pkt_offset may legitimately see 0 as a valid offset now, so
switch to using USHRT_MAX to indicate an invalid offset.
Note also that I would generally prefer to replace the buffers of the
current sk_buff with a new kmalloc'd buffer of the right size, ditching the
old data and frags as this makes the handling of MSG_PEEK easier and
removes the re-decryption issue, but this looks like quite a complicated
thing to achieve. skb_morph() looks half way to what I want, but I don't
want to have to allocate a new sk_buff.
CVE-2026-64009
High · 7.8
CWE-787 Jul 19, 2026
xfrm: Check for underflow in xfrm_state_mtu
In the Linux kernel, the following vulnerability has been resolved:
xfrm: Check for underflow in xfrm_state_mtu
Leo Lin reported OOB write issue in esp component:
xfrm_state_mtu() returns u32 but performs its arithmetic in unsigned
modulo-2^32 space using an attacker-influenced "header_len + authsize +
net_adj" subtracted from a small "mtu" argument. A nobody user can
install an IPv4 ESP tunnel SA with a large authentication key
(XFRMA_ALG_AUTH_TRUNC, e.g. hmac(sha512), 64-byte key, 64-byte trunc),
configure a small interface MTU (68 bytes), and set XFRMA_TFCPAD to a
large value. When a single UDP datagram is then sent through the
tunnel, xfrm_state_mtu() underflows to a near-2^32 value, and
esp_output() consumes it as a signed int via:
padto = min(x->tfcpad, xfrm_state_mtu(x, mtu_cached))
esp.tfclen = padto - skb->len (assigned to int)
esp.tfclen ends up negative (e.g. -207). It is sign-extended to size_t
when passed to memset() inside esp_output_fill_trailer(), producing a
~16 EB write of zeroes at skb_tail_pointer(skb). KASAN logs it as
"Write of size 18446744073709551537 at addr ffff888...".
Check for underflow and return 1. This causes the sendmsg attempt to
fail with ENETUNREACH.