Linux: >> Linux Kernel >> 3.18.31 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
USB: legousbtower: fix use-after-free on disconnect race
mutex_unlock() may access the mutex structure after releasing the lock
and therefore cannot be used to manage lifetime of objects directly
(unlike spinlocks and refcounts). [1][2]
Use a kref to release the driver data to avoid use-after-free in
mutex_unlock() when release() races with disconnect().
[1] a51749ab34d9 ("locking/mutex: Document that mutex_unlock() is
non-atomic")
[2] 2b9d9e0a9ba0 ("locking/mutex: Clarify that mutex_unlock(), and most
other sleeping locks, can still use the lock object
after it's unlocked")
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
isofs: bound Rock Ridge symlink components to the SL record
get_symlink_chunk() and the SL handling in
parse_rock_ridge_inode_internal() walk the variable-length components of
a Rock Ridge "SL" (symbolic link) record. Each component is a two-byte
header (flags, len) followed by len bytes of text, so it occupies
slp->len + 2 bytes. Both loops read slp->len and advance to the next
component, and get_symlink_chunk() additionally does
memcpy(rpnt, slp->text, slp->len), but neither checks that the component
lies within the SL record before dereferencing it.
A crafted SL record whose component declares a len that runs past the
record (rr->len) therefore triggers an out-of-bounds read of up to 255
bytes. When the record sits at the tail of its backing buffer - for
example a small kmalloc()ed continuation block reached through a CE
record - the read crosses the allocation; get_symlink_chunk() then
copies the out-of-bounds bytes into the symlink body returned to user
space by readlink(), disclosing adjacent kernel memory.
ISO 9660 images are routinely mounted from untrusted removable media -
desktop environments auto-mount them (e.g. via udisks2) without
CAP_SYS_ADMIN - so the record contents are attacker-controlled.
Reject any component that does not fit in the remaining record bytes
before using it. In get_symlink_chunk() return NULL, like the existing
output-buffer (plimit) checks, so a malformed record makes readlink()
fail with -EIO rather than silently returning a truncated target; in
parse_rock_ridge_inode_internal() stop the inode-size walk.
CVSS Score
7.1
EPSS Score
0.002
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
partitions: aix: bound the pp_count scan to the ppe array
aix_partition() reads the physical volume descriptor into a fixed-size
struct pvd and then scans its physical-partition-extent array:
int numpps = be16_to_cpu(pvd->pp_count);
...
for (i = 0; i < numpps; i += 1) {
struct ppe *p = pvd->ppe + i;
...
lp_ix = be16_to_cpu(p->lp_ix);
pvd points at a single kmalloc()'d struct pvd whose ppe[] member holds a
fixed ARRAY_SIZE(pvd->ppe) (1016) entries, but the loop runs up to the
on-disk pp_count. pp_count is an unvalidated __be16 read straight from
the descriptor, so a crafted AIX image with pp_count larger than 1016
drives the loop to read pvd->ppe[i] past the end of the allocation (up
to 65535 entries, ~2 MB out of bounds).
The partition scan runs without mounting anything, when a block device
with a crafted AIX/IBM partition table appears (an attacker-supplied
image attached with losetup -P, or a device auto-scanned by udev), via
msdos_partition() -> aix_partition().
Clamp the scan to the number of entries the ppe[] array can hold.
CVSS Score
7.1
EPSS Score
0.002
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
udf: validate sparing table length as an entry count, not a byte count
udf_load_sparable_map() accepts a sparing table when
sizeof(*st) + le16_to_cpu(st->reallocationTableLen) > sb->s_blocksize
is false, i.e. it treats reallocationTableLen as a number of BYTES that
must fit in the block. But the table is walked as an array of 8-byte
sparingEntry elements:
for (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) {
struct sparingEntry *entry = &st->mapEntry[i];
... entry->origLocation ...
}
in udf_get_pblock_spar15() and udf_relocate_blocks(). A
reallocationTableLen of N therefore passes the check whenever
sizeof(*st) + N <= blocksize, yet the consumers index
sizeof(*st) + N * sizeof(struct sparingEntry) bytes -- up to ~8x the
block. On a crafted UDF image this is an out-of-bounds read in
udf_get_pblock_spar15(); udf_relocate_blocks() additionally feeds the
same length to udf_update_tag(), whose crc_itu_t() reads far past the
block, and its memmove() through st->mapEntry[] is an out-of-bounds
write.
Validate reallocationTableLen as the entry count it is, with
struct_size().
CVSS Score
7.8
EPSS Score
0.002
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
udf: validate VAT header length against the VAT inode size
udf_load_vat() takes the virtual partition's start offset straight from
the on-disk VAT 2.0 header without checking it against the VAT inode
size:
map->s_type_specific.s_virtual.s_start_offset =
le16_to_cpu(vat20->lengthHeader);
map->s_type_specific.s_virtual.s_num_entries =
(sbi->s_vat_inode->i_size -
map->s_type_specific.s_virtual.s_start_offset) >> 2;
lengthHeader is a fully attacker-controlled 16-bit value. If it exceeds
the VAT inode size, the s_num_entries subtraction underflows to a huge
count, which defeats the "block > s_num_entries" bound in
udf_get_pblock_virt15(); and on the ICB-inline path that function reads
((__le32 *)(iinfo->i_data + s_start_offset))[block]
so a large s_start_offset indexes past the inode's in-ICB data. Mounting
a crafted UDF image with a virtual (VAT) partition then triggers an
out-of-bounds read.
Reject a VAT whose header length does not leave room for at least one
entry within the VAT inode.
CVSS Score
7.1
EPSS Score
0.002
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
crypto: qat - protect service table iterations with service_lock
The service_table list is protected by service_lock when entries are
added or removed (in adf_service_add() and adf_service_remove()), but
several functions iterate over the list without holding this lock.
A concurrent adf_service_register() or adf_service_unregister() call
could modify the list during traversal, leading to list corruption or
a use-after-free.
Fix this by holding service_lock across all list_for_each_entry()
iterations of service_table in adf_dev_init(), adf_dev_start(),
adf_dev_stop(), adf_dev_shutdown(), adf_dev_restarting_notify(),
adf_dev_restarted_notify(), and adf_error_notifier().
The lock ordering is safe: callers of the static helpers (adf_dev_up()
and adf_dev_down()) acquire state_lock before service_lock, and no
event_hld callback or service_lock holder ever acquires state_lock in
the reverse order.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
NFSv4: include MAY_WRITE in open permission mask for O_TRUNC
POSIX requires write permission to truncate a file, so an open() that
specifies O_TRUNC must be authorized for write access regardless of the
O_ACCMODE access mode.
nfs_open_permission_mask() builds the access mask passed to
nfs_may_open(), which is the local authorization gate for OPENs the
client serves itself from a cached write delegation via the
can_open_delegated() path in nfs4_try_open_cached(). The mask is
derived from O_ACCMODE alone, so an open(O_RDONLY | O_TRUNC) against a
file the caller cannot write requests only MAY_READ and passes the
local check. The OPEN is then satisfied locally and the truncation is
issued to the server as a SETATTR(size=0) over the delegation stateid,
which the server accepts under standard write-delegation semantics.
POSIX requires that this open fail with EACCES.
Include MAY_WRITE in the mask whenever O_TRUNC is set so the local
check matches the access the server would have enforced.
CVSS Score
7.1
EPSS Score
0.002
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
i2c: core: fix adapter deregistration race
Adapters can be looked up by their id using i2c_get_adapter() which
takes a reference to the embedded struct device.
Remove the adapter from the IDR before tearing it down during
deregistration (and on registration failure) to make sure its resources
are not accessed after having been freed (e.g. the device name).
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-25
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.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-07-25
In the Linux kernel, the following vulnerability has been resolved:
Input: touchwin - reset the packet index on every complete packet
tw_interrupt() accumulates each non-zero serial byte into a fixed
three-byte buffer with a running index that is only reset once a full
packet has been received *and* the device's two Y bytes agree:
tw->data[tw->idx++] = data;
if (tw->idx == TW_LENGTH && tw->data[1] == tw->data[2]) {
...
tw->idx = 0;
}
The reset is gated on tw->data[1] == tw->data[2], a value the device
controls. A malicious, malfunctioning or counterfeit Touchwindow
peripheral can stream non-zero bytes whose 2nd and 3rd bytes differ: the
index reaches TW_LENGTH without the equality holding, is never reset, and
keeps growing, so tw->data[tw->idx++] walks off the end of the three-byte
array and the rest of the heap-allocated struct tw, one attacker-chosen
byte at a time -- an unbounded, device-driven heap out-of-bounds write.
Reset the index on every completed packet and report an event only when
the two Y bytes match, like the other serio touchscreen drivers do.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-07-25