CVE-2026-68388 — smb/client: handle overlapping allocated ranges in fallocate

Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

smb/client: handle overlapping allocated ranges in fallocate

smb3_simple_fallocate_range() can skip holes when an allocated range returned by the server starts before the current fallocate offset. The skipped hole is not zero-filled, but fallocate still returns success. A later write to that hole may therefore fail with ENOSPC.

The function queries allocated ranges so that it can preserve existing contents and write zeroes only into holes. However, the server may return a range that starts before the current fallocate offset.

For example, assume the fallocate request is [100, 400) and the only allocated range returned by the server is [0, 200):

Request: [100, 400) Server range: [ 0, 200) allocated

Correct: [100, 200) allocated data, skip [200, 400) hole, zero-fill

Current: [100, 300) skipped [300, 400) zero-filled afterwards

The current code adds the full server range length, 200, to the current offset 100 and moves to 300. As a result, the hole in [200, 300) is skipped without being zero-filled.

Fix this by advancing only over the part of the allocated range that overlaps the current fallocate offset. Ignore ranges that end before the current offset and reject ranges whose end offset overflows.

This also prevents a malformed range length from causing an out-of-bounds zero-buffer read.

USN-8781-1 — linux-nvidia-tegra vulnerabilities

Affected: Ubuntu:24.04:LTS: linux-nvidia-tegra

It was discovered that some Arm processors could complete a broadcast translation lookaside buffer (TLB) invalidation before memory writes made through the invalidated translation were globally observed. A local attacker could possibly use this to write to memory after permission to do so had been revoked, bypassing memory protections or escalating privileges. (CVE-2025-10263)

Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - ARM64 architecture; - User-space API (UAPI); - Kernel build system; - ARM32 architecture; - PowerPC architecture; - RISC-V architecture; - S390 architecture; - User-Mode Linux (UML); - x86 architecture; - Cryptographic API; - Intel NPU Driver; - Compute Acceleration Framework; - ACPI drivers; - Drivers core; - DRBD Distributed Replicated Block Device drivers; - Rados block device (RBD) driver; - Ublk userspace block driver; - Compressed RAM block device driver; - Bluetooth drivers; - Hardware crypto device drivers; - CXL (Compute Express Link) drivers; - Arm Firmware Framework for ARMv8-A(FFA); - EFI core; - FPGA Framework; - GPU drivers; - HID subsystem; - Hardware monitoring drivers; - I2C subsystem; - I3C subsystem; - InfiniBand drivers; - Input Device core drivers; - Input Device (Mouse) drivers; - IOMMU subsystem; - Multiple devices driver; - Media…

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CVE-2026-68388 — smb/client: handle overlapping allocated ranges in fallocate

USN-8781-1 — linux-nvidia-tegra vulnerabilities