CVE-2026-80578 — fbdev: core: Fix pointer desynchronization in fb_io_read()

Affected: Linux

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

fbdev: core: Fix pointer desynchronization in fb_io_read()

In fb_io_read(), if copy_to_user() performs a partial copy (e.g., due to a faulty user buffer), the loop adjusts the chunk size 'c' and updates the remaining 'count'. However, the hardware 'src' pointer has already been eagerly advanced by the original chunk size.

If the loop is allowed to continue, the read will resume from an incorrect, over-advanced offset. Since the remaining 'count' was only decremented by the successful bytes, this desynchronization causes the next iterations to execute more hardware reads than originally bounded, eventually leading to out-of-bounds I/O reads.

Fix this by breaking out of the loop immediately upon a partial copy_to_user(). A partial copy indicates a faulty user buffer, making subsequent read attempts futile. Breaking out ensures we return the number of successfully read bytes without risking out-of-bounds hardware accesses in subsequent mismatched iterations.

USN-8886-1 — linux-nvidia-tegra vulnerabilities

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

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: - NVDIMM (Non-Volatile Memory Device) drivers; - Handshake API; - ARM32 architecture; - ARM64 architecture; - MIPS architecture; - OpenRISC architecture; - PowerPC architecture; - S390 architecture; - x86 architecture; - Block layer subsystem; - Cryptographic API; - Intel NPU Driver; - Android drivers; - Rados block device (RBD) driver; - Bluetooth drivers; - Hardware random number generator core; - TPM device driver; - CPU frequency scaling framework; - Hardware crypto device drivers; - DMA engine subsystem; - FireWire subsystem; - Arm Firmware Framework for ARMv8-A(FFA); - GPIO subsystem; - GPU drivers; - HID subsystem; - Hardware monitoring drivers; - CoreSight HW tracing drivers; - I2C subsystem; - IIO ADC drivers; - IIO subsystem; - InfiniBand drivers; - Input Device core drivers; - Input Device (Mouse) drivers; - IOMMU subsystem; - Multiple devices driver; - Media drivers; - Multifunction device drivers; - Fastrpc Driver; - Amazon Nitro Secure Module driver; - MMC subsystem; - MTD block device drivers; - Ethernet bonding driver; - Network drivers; - Mellanox network drivers; - Texas Instruments network drivers; - NTB driver; - NVME drivers; - NVMEM (Non Volatile Memory) drivers; - Parport drivers…

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CVE-2026-80578 — fbdev: core: Fix pointer desynchronization in fb_io_read()

USN-8886-1 — linux-nvidia-tegra vulnerabilities