linux-gcp-6.8 vulnerabilities · Page 178

xfrm: move policy_bydst RCU sync from per-netns .exit to .pre_exit

In the Linux kernel, the following vulnerability has been resolved: xfrm: move policy_bydst RCU sync from per-netns .exit to .pre_exit The struct pernet_operations docstring in include/net/net_namespace.h explicitly warns against blocking RCU primitives in .exit handlers: Exit methods using blocking RCU primitives, such as synchronize_rcu(), should be implemented via exit_batch. [...] Please, avoid synchronize_rcu() at all, where it's possible. Note that a combination of pre_exit() and exit() can be used, since a synchronize_rcu() is guaranteed between the calls. xfrm_policy_fini() violates this: it calls sync

• Update to 6.8.0-1070.78~22.04.1

drm/hyperv: validate resolution_count and fix WIN8 fallback

In the Linux kernel, the following vulnerability has been resolved: drm/hyperv: validate resolution_count and fix WIN8 fallback A SYNTHVID_RESOLUTION_RESPONSE with resolution_count > 64 walks past the supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT] array in the parse loop. Bound resolution_count against the array size, folded into the existing zero-check. When the WIN10 resolution probe fails, the caller in hyperv_connect_vsp() left hv->screen_*_max / preferred_* unpopulated, which sets mode_config.max_width / max_height to 0 and makes drm_internal_framebuffer_create() reject every userspace framebuffer with -EINVAL. The pre-WIN10 bran

• Update to 6.8.0-1070.78~22.04.1

net/handshake: Take a long-lived file reference at submit

In the Linux kernel, the following vulnerability has been resolved: net/handshake: Take a long-lived file reference at submit handshake_nl_accept_doit() needs the file pointer backing req->hr_sk->sk_socket to survive the window between handshake_req_next() and the subsequent FD_PREPARE() and get_file(). The submit-side sock_hold() does not provide that. sk_refcnt keeps struct sock alive, but struct socket is owned by sock->file: when the consumer fputs the last file reference, sock_release() tears the socket down regardless of any sock_hold. Add an hr_file pointer to struct handshake_req and acquire an explicit reference on sock->file dur

tcp: Fix out-of-bounds access for twsk in tcp_ao_established_key().

In the Linux kernel, the following vulnerability has been resolved: tcp: Fix out-of-bounds access for twsk in tcp_ao_established_key(). lockdep_sock_is_held() was added in tcp_ao_established_key() by the cited commit. It can be called from tcp_v[46]_timewait_ack() with twsk. Since it does not have sk->sk_lock, the lockdep annotation results in out-of-bound access. $ pahole -C tcp_timewait_sock vmlinux | grep size /* size: 288, cachelines: 5, members: 8 */ $ pahole -C sock vmlinux | grep sk_lock socket_lock_t sk_lock; /* 440 192 */ Let's not use lockdep_sock_is_held() for TCP_TIME_WAIT.

• Update to 6.8.0-1067.75~22.04.1

userfaultfd: gate must_wait writability check on pte_present()

In the Linux kernel, the following vulnerability has been resolved: userfaultfd: gate must_wait writability check on pte_present() userfaultfd_must_wait() and userfaultfd_huge_must_wait() read the PTE without taking the page table lock and then apply pte_write() / huge_pte_write() to it. Those accessors decode bits from the present encoding only; on a swap or migration entry they read the offset bits that happen to share the same position and return an undefined result. The intent of the check is "is this fault still WP-blocked?". A non-marker swap entry means the page is in transit -- the userfault context the original fault delivered a

KVM: x86: Unconditionally recompute CR8 intercept on PPR update

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Unconditionally recompute CR8 intercept on PPR update The TPR_THRESHOLD field in the VMCS is used by VMX to induce VM exits when the guest's virtual TPR falls under the specified threshold, allowing KVM to inject previously masked interrupts. KVM handles these VM exits in handle_tpr_below_threshold(). Commit eb90f3417a0c ("KVM: vmx: speed up TPR below threshold vmexits") optimized this function by calling apic_update_ppr() instead of raising KVM_REQ_EVENT. apic_update_ppr() then raises KVM_REQ_EVENT if there is a pending, deliverable interrupt. However, if there

ACPI: CPPC: Suppress UBSAN warning caused by field misuse

In the Linux kernel, the following vulnerability has been resolved: ACPI: CPPC: Suppress UBSAN warning caused by field misuse The definition of reg->access_width changes depending on the reg->space_id type. Type ACPI_ADR_SPACE_PLATFORM_COMM uses access_width to indicate the PCC region, which can result in a UBSAN if the value is greater than 4. For example: UBSAN: shift-out-of-bounds in drivers/acpi/cppc_acpi.c:1090:9 shift exponent 32 is too large for 32-bit type 'int' CPU: 61 UID: 0 PID: 1220 Comm: (udev-worker) Not tainted 7.0.10-201.fc44.aarch64 #1 PREEMPT(lazy) Hardware name: To be filled by O.E.M. Call trace: ...(trimming)

ACPI: NFIT: core: Fix possible NULL pointer dereference

In the Linux kernel, the following vulnerability has been resolved: ACPI: NFIT: core: Fix possible NULL pointer dereference After commit 9b311b7313d6 ("ACPI: NFIT: Install Notify() handler before getting NFIT table"), acpi_nfit_probe() installs an ACPI notify handler for the NFIT device before checking the presence of the NFIT table. If that table is not there, 0 is returned without allocating the acpi_desc object and setting the driver data pointer of the NFIT device. If the platform firmware triggers an NFIT_NOTIFY_UC_MEMORY_ERROR notification on the NFIT device at that point, acpi_nfit_uc_error_notify() will dereference a NULL pointer.

ACPI: NFIT: core: Fix acpi_nfit_init() error cleanup

In the Linux kernel, the following vulnerability has been resolved: ACPI: NFIT: core: Fix acpi_nfit_init() error cleanup If acpi_nfit_init() fails after adding the acpi_desc object to the acpi_descs list, that object is never removed from that list because the acpi_nfit_shutdown() devm action is not added for the NFIT device in that case. Next, the acpi_nfit_init() failure causes acpi_nfit_probe() to fail, the acpi_desc object is freed, and a dangling pointer is left behind in the acpi_descs. Any subsequent ACPI Machine Check Exception will trigger nfit_handle_mce() which iterates over acpi_descs and so a use-after-free will occur. Moreo

bpf: Support for hardening against JIT spraying

In the Linux kernel, the following vulnerability has been resolved: bpf: Support for hardening against JIT spraying The BPF JIT allocator packs many small programs into larger executable allocations and reuses space within those allocations as programs are loaded and freed. When fresh code is written into space that a previous program occupied, an indirect jump into the new program can reuse a branch prediction left behind by the old one. Flush the indirect branch predictors before reusing JIT memory so that indirect jumps into a newly written program don't reuse predictions from an old program that occupied the same space. Introduce bpf_

x86/bugs: Enable IBPB flush on BPF JIT allocation

In the Linux kernel, the following vulnerability has been resolved: x86/bugs: Enable IBPB flush on BPF JIT allocation Enable hardening against JIT spraying when Spectre-v2 mitigations are in use. Specifically, issue an IBPB flush on BPF JIT memory reuse. Skip enabling the IBPB flush if the BPF dispatcher is already using a retpoline sequence. This hardening applies only when BPF-JIT is in use. Guard the enabling under CONFIG_BPF_JIT so that bugs.c still builds with CONFIG_BPF_JIT=n.

usb: gadget: function: rndis: add length check for header

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: function: rndis: add length check for header Add a length check for the rndis header in rndis_rm_hdr, to ensure that MessageType, MessageLength, DataOffset, and DataLength fields are present before they are accessed.

iio: accel: bmc150: clamp the device-reported FIFO frame count

In the Linux kernel, the following vulnerability has been resolved: iio: accel: bmc150: clamp the device-reported FIFO frame count __bmc150_accel_fifo_flush() copies the number of samples the device reports in its hardware FIFO into an on-stack buffer u16 buffer[BMC150_ACCEL_FIFO_LENGTH * 3]; which is sized for at most BMC150_ACCEL_FIFO_LENGTH (32) samples. The frame count is read from the FIFO_STATUS register and only masked to its 7 valid bits: count = val & 0x7F; so it can be 0..127. The only other limit applied to it is the optional caller-supplied sample budget: if (samples && count > samples) count = samples; which does not

iio: accel: kxsd9: fix runtime PM imbalance on write_raw() error

In the Linux kernel, the following vulnerability has been resolved: iio: accel: kxsd9: fix runtime PM imbalance on write_raw() error kxsd9_write_raw() takes a runtime PM reference with pm_runtime_get_sync() but returns -EINVAL directly when a scale with a non-zero integer part is requested, skipping the matching pm_runtime_put_autosuspend(). This leaks a runtime PM usage-counter reference on every such write, after which the device can no longer autosuspend. Set the error code and fall through to the existing put instead of returning early.

iio: adc: lpc32xx: Initialize completion before requesting IRQ

In the Linux kernel, the following vulnerability has been resolved: iio: adc: lpc32xx: Initialize completion before requesting IRQ In the report from Jaeyoung Chung: "lpc32xx_adc_probe() in drivers/iio/adc/lpc32xx_adc.c registers its interrupt handler with devm_request_irq() before it initializes st->completion with init_completion(). If an interrupt arrives after devm_request_irq() and before init_completion(), the handler calls complete() on an uninitialized completion, causing a kernel panic. The probe path, in lpc32xx_adc_probe(): iodev = devm_iio_device_alloc(&pdev->dev, sizeof(*st)); /* st kzalloc-zeroed */ ... retval =

iio: chemical: scd30: Cleanup initializations and fix sign-extension bug

In the Linux kernel, the following vulnerability has been resolved: iio: chemical: scd30: Cleanup initializations and fix sign-extension bug Include linux/bitfield.h for FIELD_GET(). Create new macros for bit manipulation in combination with manual bit manipulation being replaced with FIELD_GET(). The current variable declaration and initializations are barely readable and use comma separations across multiple lines. Refactor the initializations so that mantissa and exp have separate declarations and sign gets initialized later. In addition (and due to the nature of the cleanup), fix a sign-extension bug where, float32 would get bitwise

iio: event: Fix event FIFO reset race

In the Linux kernel, the following vulnerability has been resolved: iio: event: Fix event FIFO reset race `iio_event_getfd()` creates the event file descriptor with `anon_inode_getfd()`, which allocates a new fd, creates the anonymous file and installs it in the process fd table before returning to the caller. The IIO code resets the event FIFO after `anon_inode_getfd()` has returned, but before `IIO_GET_EVENT_FD_IOCTL` has copied the fd number to userspace. But since fd tables are shared between threads, another thread can guess the newly allocated fd number and issue a `read()` on it as soon as the fd has been installed. This means the

iio: gyro: bmg160: bail out when bandwidth/filter is not in table

In the Linux kernel, the following vulnerability has been resolved: iio: gyro: bmg160: bail out when bandwidth/filter is not in table bmg160_get_filter() walks bmg160_samp_freq_table[] looking for the entry matching the bw_bits value read from the chip: for (i = 0; i < ARRAY_SIZE(bmg160_samp_freq_table); ++i) { if (bmg160_samp_freq_table[i].bw_bits == bw_bits) break; } *val = bmg160_samp_freq_table[i].filter; If no entry matches, i ends up equal to the array size and the next line reads one slot past the end. bmg160_set_filter() has the same shape, driven by 'val' instead of bw_bits. smatch flags both: drivers/iio/gyro/bmg160_

iio: light: gp2ap002: fix runtime PM leak on read error

In the Linux kernel, the following vulnerability has been resolved: iio: light: gp2ap002: fix runtime PM leak on read error gp2ap002_read_raw() calls pm_runtime_get_sync() before reading the lux value, but if gp2ap002_get_lux() fails, it returns directly. This skips the pm_runtime_put_autosuspend() call at the "out" label, permanently leaking a runtime PM reference and preventing the device from autosuspending. Replace the direct return with a "goto out" to ensure the reference is properly dropped on the error path.

iio: pressure: mpl115: fix runtime PM leak on read error

In the Linux kernel, the following vulnerability has been resolved: iio: pressure: mpl115: fix runtime PM leak on read error mpl115_read_raw() takes a runtime PM reference with pm_runtime_get_sync() before reading the processed pressure or raw temperature, but on the read error path it returns without calling pm_runtime_put_autosuspend(). Each failed read therefore leaks a runtime PM reference and prevents the device from autosuspending. Drop the reference before checking the return value so both the success and error paths are balanced.