In the Linux kernel, the following vulnerability has been resolved:
Input: iforce - bound the device-reported force-feedback effect index
iforce_process_packet() handles a status report (packet id 0x02) by
taking a force-feedback effect index straight from the device wire and
using it to address the per-effect state array:
i = data[1] & 0x7f;
if (data[1] & 0x80) {
if (!test_and_set_bit(FF_CORE_IS_PLAYED,
iforce->core_effects[i].flags))
...
} else if (test_and_clear_bit(FF_CORE_IS_PLAYED,
iforce->core_effects[i].flags)) {
...
}
The index is masked only with 0x7f, so it ranges 0..127, but
core_effects[] holds only IFORCE_EFFECTS_MAX (32) entries. For an index
of 32..127 the test_and_set_bit()/test_and_clear_bit() is an
out-of-bounds single-bit read-modify-write past the array. core_effects[]
is the second-to-last member of struct iforce, so the write lands in the
trailing members and beyond the embedding kzalloc()'d iforce_serio /
iforce_usb object.
data[1] is unvalidated device payload on both transports (the USB
interrupt endpoint and serio), and the status path is not gated on force
feedback being present, so a malicious or counterfeit device can set or
clear a bit at an attacker-chosen offset past the object.
Reject an out-of-range index instead of indexing with it. Bound against
the array dimension IFORCE_EFFECTS_MAX rather than dev->ff->max_effects so
the check guarantees memory safety regardless of how many effects the
device registered. A legitimate "effect started/stopped" status always
carries an index below IFORCE_EFFECTS_MAX, so well-formed devices are
unaffected; the neighbouring mark_core_as_ready() loop is already bounded
and is left untouched.
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.
In the Linux kernel, the following vulnerability has been resolved:
Input: elan_i2c - prevent division by zero and arithmetic underflow
The Elan I2C touchpad driver queries the device for its physical
dimensions and trace counts to calculate the device resolution and width.
However, if the device firmware or device tree provides invalid zero
values for x_traces or y_traces, it results in a fatal division-by-zero
exception leading to a kernel panic during device probe.
Add checks to ensure these parameters are non-zero before performing
the division. If invalid trace values are detected, fall back to a safe
default of 1.
Additionally, prevent an arithmetic underflow in the touch reporting
logic. Previously, if the calculated or fallback width was smaller than
ETP_FWIDTH_REDUCE (90), the subtraction would underflow, resulting in a
massive unsigned integer being reported to userspace. Clamp the adjusted
width to a minimum of 0 to safely handle small physical dimensions and
fallback scenarios.
Completing the probe with safe fallback values ensures the sysfs nodes
are created, keeping the firmware update path intact so a recovery
firmware can be flashed to the device.
In the Linux kernel, the following vulnerability has been resolved:
fuse-uring: make a fuse_req on SQE commit only findable after memcpy
Bad userspace might try to trick us and send commit SQEs request
unique / commit-id of requests that are not even send to
fuse-server (io_uring_cmd_done() not called) yet.
fuse_uring_commit_fetch() ends the fuse request when the ring entry
has a wrong state, but that could have caused a use-after-free
with the memcpy operations in fuse_uring_send_in_task().
In order to avoid such races the call of fuse_uring_add_to_pq()
is moved after the copy operations and just before completing
the io-uring request - malicious userspace cannot find the request
anymore until all prepration work in fuse-client/kernel is completed.
This also moves fuse_uring_add_to_pq() a bit up in the code to
avoid a forward declaration. Also not with a preparation commit,
to make it easier to back port to older kernels.
In the Linux kernel, the following vulnerability has been resolved:
fuse-uring: Avoid queue->stopped races and set/read that value under lock
There are several readers of queue->stopped that check the value
under lock, but fuse_uring_commit_fetch() did not and actually
the value was not set under the lock in fuse_uring_abort_end_requests()
either. Especially in fuse_uring_commit_fetch it is important
to check under a lock, because due to races 'struct fuse_req'
might be freed with fuse_request_end, but another thread/cpu
might already do teardown work.
In the Linux kernel, the following vulnerability has been resolved:
fuse-uring: Avoid use-after-free in fuse_uring_async_stop_queues
fuse_uring_async_stop_queues() might run when the last reference
on ring->queue_refs was already dropped.
In order to avoid an early destruction a reference on struct fuse_conn
is now taken before starting fuse_uring_async_stop_queues() and that
reference is only released when that delayed work queue terminates.
In the Linux kernel, the following vulnerability has been resolved:
fuse-uring: end fuse_req on io-uring cancel task work
When io_uring delivers task work with tw.cancel set (PF_EXITING,
PF_KTHREAD fallback, or percpu_ref_is_dying on the ring context),
fuse_uring_send_in_task() takes the cancel branch, assigns
-ECANCELED, and falls through to fuse_uring_send(). That path only
flips the entry to FRRS_USERSPACE and completes the io_uring cmd;
it never discharges the ring entry's owning reference to the
fuse_req that fuse_uring_add_req_to_ring_ent() handed it at
dispatch time.
fuse_uring_send_in_task()
tw.cancel == true
err = -ECANCELED
fuse_uring_send(ent, cmd, err, issue_flags)
ent->state = FRRS_USERSPACE
list_move(&ent->list, &queue->ent_in_userspace)
ent->cmd = NULL
io_uring_cmd_done(-ECANCELED)
/* ent->fuse_req still set, req still hashed */
The fuse_req stays linked on fpq->processing[hash] and
fuse_request_end() is never invoked. The originating syscall
thread blocks in D-state in request_wait_answer() until
fuse_abort_conn() runs, which can be the entire connection
lifetime. For FR_BACKGROUND requests fc->num_background is never
decremented either, so repeated cancels inflate the counter until
max_background is hit and all later background ops stall. tw.cancel does
not imply a connection abort (e.g. a single io_uring worker thread exits
while the fuse connection stays up), so this cannot be left for
fuse_abort_conn() to clean up.
Ending the req but still routing the entry through fuse_uring_send()
is not enough: that leaves a req-less entry on ent_in_userspace, and
ent_list_request_expired() dereferences ent->fuse_req unconditionally
on the head of that list, which would then NULL-deref.
Fix the cancel branch to release the entry directly. Remove it from the
queue, complete the io_uring cmd, end the fuse_req, free the entry, and
drop its queue_refs (waking the teardown waiter if it was the last).
In the Linux kernel, the following vulnerability has been resolved:
fuse-uring: fix EFAULT clobber in fuse_uring_commit
copy_from_user() returns the number of bytes not copied as an unsigned
residual on failure (1..sizeof(struct fuse_out_header)). fuse_uring_commit
stores that residual in ssize_t err, sets req->out.h.error to -EFAULT,
then jumps to out: with err still holding the positive residual.
err = copy_from_user(&req->out.h, &ent->headers->in_out,
sizeof(req->out.h));
if (err) {
req->out.h.error = -EFAULT;
goto out; /* err is the positive residual */
}
...
out:
fuse_uring_req_end(ent, req, err);
fuse_uring_req_end() then runs
if (error)
req->out.h.error = error;
which overwrites the just-assigned -EFAULT with the positive residual.
FUSE callers such as fuse_simple_request() test err < 0 to detect
failure, so the positive value is interpreted as success and the
caller proceeds with an uninitialised or partial req->out.args.
Fix by assigning err = -EFAULT in the failure branch before jumping
to out, so fuse_uring_req_end() receives a negative errno and sets
req->out.h.error to -EFAULT.
In the Linux kernel, the following vulnerability has been resolved:
fuse: clear intr_entry in fuse_resend and fuse_remove_pending_req
When fuse_resend() moves a request from fpq->processing back to
fiq->pending, it sets FR_PENDING and clears FR_SENT but does not
remove the requests intr_entry from fiq->interrupts. If the
request had FR_INTERRUPTED set from a prior signal, intr_entry
remains dangling on fiq->interrupts. When the requesting task
then receives a fatal signal, fuse_remove_pending_req() sees
FR_PENDING=1, removes the request from fiq->pending and frees it
via the refcount path, also without cleaning intr_entry. The
stale intr_entry causes use-after-free when fuse_read_interrupt()
iterates fiq->interrupts:
- list_del_init(&req->intr_entry) -> UAF write on freed slab
- req->in.h.unique -> UAF read, data leaked to userspace
Remove intr_entry from fiq->interrupts in fuse_resend() for
interrupted requests before they are placed back on fiq->pending.
Add a WARN_ON if the intr_entry is not empty on request destruction.
In the Linux kernel, the following vulnerability has been resolved:
fuse: re-lock request before returning from fuse_ref_folio()
fuse_ref_folio() unlocks the request but does not re-lock it before
returning. fuse_chan_abort() can end the request and the async end
callback (eg fuse_writepage_free()) can free the args while the
subsequent copy chain logic after fuse_ref_folio() accesses them,
leading to use-after-free issues.
Fix this by locking the request in fuse_ref_folio() before returning.