Linux vulnerabilities

In the Linux kernel, the following vulnerability has been resolved: uprobes: Fix NULL pointer dereference in hprobe_expire() Forking a task that has a pending uretprobe can oops the kernel with a NULL pointer dereference in the clone() path: BUG: kernel NULL pointer dereference, address: 0000000000000018 Oops: 0002 [#1] SMP NOPTI RIP: 0010:hprobe_expire CR2: 0000000000000018 Call Trace: uprobe_copy_process copy_process kernel_clone __x64_sys_clone do_syscall_64 entry_SYSCALL_64_after_hwframe This was found on real hosts on Meta fleet. I've got the impression that this is what is happening: CPU 1 CPU 2 (traced task) ----- ------------------- hit uprobe, prepare_uretprobe(): hprobe LEASED, refcount >= 1 uprobe_unregister() put_uprobe(): refcount -> 0 fork() -> dup_utask() hprobe_expire(hprobe, true) try_get_uprobe() -> NULL get_uprobe(NULL) <-- Oops Only take the extra reference when the uprobe is non-NULL; a NULL means it is gone and is the correct value to return.

In the Linux kernel, the following vulnerability has been resolved: ublk: reset kernel-owned dev_info fields in ublk_ctrl_add_dev() ublk_ctrl_add_dev() memcpy()s the userspace ublksrv_ctrl_dev_info into ub->dev_info and then fixes up the fields the driver owns, but misses ->state and ->ublksrv_pid. A device added with ->state = UBLK_S_DEV_LIVE passes the "->state != UBLK_S_DEV_DEAD" test that ublk_stop_dev_unlocked() uses as its proxy for "a disk is attached", while ->ub_disk is still NULL, so DEL_DEV right after ADD_DEV oopses in del_gendisk(). UBLK_S_DEV_QUIESCED plus UBLK_F_USER_RECOVERY dies one step earlier, in ublk_force_abort_dev(). A poisoned ->state also gets START_USER_RECOVERY and the char device read/write path onto a device that was never started, and wedges START_DEV at -EEXIST. A poisoned ->ublksrv_pid just makes GET_DEV_INFO report an unrelated task as the ublk server. Reset both after the memcpy(), as ublk_detach_disk() does. Userspace only ever reads these back, so correcting them silently breaks nothing. ADD_DEV has copied ->state in unsanitized since ublk was merged, but back then it was harmless: the gendisk was allocated during ADD_DEV, and both teardown and the START_DEV -EEXIST check keyed off disk_live() rather than ->state. The oops became reachable once the disk allocation moved to START_DEV and those checks switched to ->state.

In the Linux kernel, the following vulnerability has been resolved: gpio: pch: use raw_spinlock_t for the register lock pch_irq_type() is registered as the irq_chip .irq_set_type callback and takes chip->spinlock with spin_lock_irqsave(). This callback is reached from __setup_irq() -> __irq_set_trigger() -> chip->irq_set_type() while the caller holds desc->lock, a raw_spinlock_t, with hardirqs disabled. That context is not sleepable, but on PREEMPT_RT a regular spinlock_t is an rtmutex-backed sleeping lock, so acquiring it there is invalid. This was confirmed on a PREEMPT_RT kernel with lockdep (PROVE_RAW_LOCK_NESTING and DEBUG_ATOMIC_SLEEP). A grounded PoC mirrored pch_irq_type()'s locking and drove it through the real genirq carrier irq_set_irq_type() -> __irq_set_trigger() -> chip->irq_set_type(), i.e. the same __irq_set_trigger() edge that __setup_irq() takes for a requested IRQ. With the original spin_lock_irqsave() edge lockdep reported an invalid wait context, immediately followed by: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 95, name: insmod hardirqs last disabled at (3784): _raw_spin_lock_irqsave+0x4f/0x60 rt_spin_lock+0x3a/0x1c0 repro_irq_set_type+0x64/0xa0 [pch_repro] __irq_set_trigger+0x69/0x140 irq_set_irq_type+0x78/0xd0 Switching the mirrored lock to raw_spinlock_t made both splats go away. Convert the register lock to raw_spinlock_t. The same lock also serializes the GPIO direction/value callbacks and the suspend/resume register save/restore, but all of those critical sections only perform MMIO register accesses (ioread32()/iowrite32()) and irq_set_handler_locked(); none of them contain sleepable operations. Keeping this register lock non-sleeping is therefore appropriate for the irqchip callbacks and does not change the GPIO-side locking contract. This is the same class of issue and fix as recently addressed for other GPIO controllers, e.g. commit 286533cb14a3 ("gpio: sch: use raw_spinlock_t in the irq startup path") and commit 90f0109019e6 ("gpio: eic-sprd: use raw_spinlock_t in the irq startup path").

In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: fix skb leak on flow key update failure during ct ovs_ct_execute() always steals or frees the skb on failure while ovs_flow_key_update() does not. So, if it fails and we return right away, the skb ends up leaked. Fix that by breaking instead and letting the common error handling code at the bottom of the loop to free the skb properly. This is a very unlikely scenario as it requires the packet to become unparseable by applying a set of actions on a previously parseable skb, but should be fixed nevertheless. Reported by Sashiko.

In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Close speculative mem read possibility The domain value is extracted from a given CCA or EP11 ioctl struct when a CPRB is about to be sent. Thus this is a user controlled value. Under some special conditions (custom device node used, administrative load) this value is used as an array index after bounds checking, but without speculation barrier. Add the missing array_index_nospec() call to prevent speculative execution where this domain value is used.

In the Linux kernel, the following vulnerability has been resolved: i2c: jz4780: Cache host clock rate at probe to prevent CCF prepare_lock deadlock Fix a severe AB/BA deadlock between the Common Clock Framework (CCF) and the I2C adapter lock, which triggers when an I2C-controlled clock generator client (like the Si5351) is registered or modified under the CCF. During an i2c client clock (generator) frequency change, the CCF acquires its global 'prepare_lock' mutex and the driver calls i2c_transfer() to update the client's chip registers, stalling for the adapter's I2C bus lock. Concurrently, an independent, parallel transfer on the same bus (e.g., a GPIO expander handling LEDs) can hold the I2C adapter lock. Inside this parallel transfer path, jz4780_i2c_set_speed() calls clk_get_rate() on the host controller's input clock to calculate bus timings. This call attempts to acquire the blocked CCF 'prepare_lock', creating a circular dependency that freezes the system. The jz4780 host controller clock itself is static and never changes at runtime. However, calling clk_get_rate() inside the active transfer path introduces an unnecessary dependency on the CCF internal locks. Eliminate this synchronous clk_get_rate() call from the active transfer path by caching the static host peripheral clock rate once - inside the private jz4780_i2c structure during jz4780_i2c_probe(). Update jz4780_i2c_set_speed() to use this cached value, safely decoupling active I2C transactions from the CCF internal locks without any risk of stale timings. Assisted-by web based Google AI (pinpointing the bug and writing the message).

In the Linux kernel, the following vulnerability has been resolved: i2c: imx: mark I2C adapter when hardware is powered down On some i.MX platforms, certain I2C client drivers keep a periodic workqueue which continues to trigger I2C transfers. During system suspend/resume, there exists a time window between: - suspend_noirq and the system entering suspend - the system starting to resume and resume_noirq In this window, the I2C controller resources such as clock and pinctrl may already be disabled or not yet restored. If a workqueue triggers an I2C transfer in this period, the driver attempts to access I2C registers while the hardware resources are unavailable, which may lead to system hang. Mark the I2C adapter as suspended during noirq suspend and block new transfers until resume, ensuring that I2C transfers are only issued when hardware resources are available.

In the Linux kernel, the following vulnerability has been resolved: can: ems_usb: validate CPC message lengths ems_usb_read_bulk_callback() walks CPC messages packed in one USB receive buffer. Check that each declared message fits in the URB payload. Also require the type-specific payload to cover the fields used by the CAN, state, error and overrun handlers.

In the Linux kernel, the following vulnerability has been resolved: can: etas_es58x: es58x_read_bulk_callback(): fix RX buffer leak on URB resubmit failure es58x_read_bulk_callback() resubmits the RX URB after processing a received packet. If the resubmit succeeds, the URB remains anchored and will be handled by the normal RX path or by teardown. However, if usb_submit_urb() fails, the callback unanchors the URB and then returns directly. This skips the existing free_urb path, so the coherent transfer buffer allocated with usb_alloc_coherent() is not released. Reuse the existing free_urb path after a resubmit failure so that the RX coherent buffer is freed before leaving the callback.

In the Linux kernel, the following vulnerability has been resolved: can: kvaser_usb_leaf: kvaser_usb_leaf_wait_cmd(): validate received command extents The wait and bulk receive paths walk variable-length commands from a USB buffer. A nonzero command shorter than CMD_HEADER_LEN can still be dispatched, and the wait path copies a matching command into a fixed caller-owned struct kvaser_cmd using the device-provided length. Reject nonzero commands that do not contain the fixed header or that extend beyond the current USB buffer item. In the wait path, also reject a matching command that exceeds the destination before copying it.

In the Linux kernel, the following vulnerability has been resolved: can: peak_usb: add bounds check for USB channel index The channel control index ctrl_idx is derived from rx->len which comes directly from a device USB payload. The mask 0x0f allows values 0-15, but the array size of usb_if->dev[] is only 2. Values 2-15 cause heap out-of-bounds read, eventually causing kernel panic in the IRQ context. Add bounds checking for ctrl_idx before the array access in both pcan_usb_pro_handle_canmsg() and pcan_usb_pro_handle_error().

In the Linux kernel, the following vulnerability has been resolved: can: peak_usb: validate uCAN receive record lengths pcan_usb_fd_decode_buf() walks uCAN records packed in one USB receive buffer. Require each record to contain the fixed header for its type, and verify CAN payload bytes before copying them into the skb.