CVE-2025-38492 — netfs: Fix race between cache write completion and ALL_QUEUED being set

Affected: Linux

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

netfs: Fix race between cache write completion and ALL_QUEUED being set

When netfslib is issuing subrequests, the subrequests start processing immediately and may complete before we reach the end of the issuing function. At the end of the issuing function we set NETFS_RREQ_ALL_QUEUED to indicate to the collector that we aren't going to issue any more subreqs and that it can do the final notifications and cleanup.

Now, this isn't a problem if the request is synchronous (NETFS_RREQ_OFFLOAD_COLLECTION is unset) as the result collection will be done in-thread and we're guaranteed an opportunity to run the collector.

However, if the request is asynchronous, collection is primarily triggered by the termination of subrequests queuing it on a workqueue. Now, a race can occur here if the app thread sets ALL_QUEUED after the last subrequest terminates.

This can happen most easily with the copy2cache code (as used by Ceph) where, in the collection routine of a read request, an asynchronous write request is spawned to copy data to the cache. Folios are added to the write request as they're unlocked, but there may be a delay before ALL_QUEUED is set as the write subrequests may complete before we get there.

If all the write subreqs have finished by the ALL_QUEUED point, no further events happen and the collection never happens, leaving the request hanging.

Fix this by queuing the collector after setting ALL_QUE…

USN-7879-1 — linux, linux-aws, linux-gcp, linux-hwe-6.14, linux-oracle, linux-realtime vulnerabilities

Affected: Ubuntu:24.04:LTS: linux-hwe-6.14

It was discovered that improper initialization of CPU cache memory could allow a local attacker with hypervisor access to overwrite SEV-SNP guest memory resulting in loss of data integrity. (CVE-2024-36331)

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; - PowerPC architecture; - S390 architecture; - x86 architecture; - Network block device driver; - Character device driver; - Clock framework and drivers; - Data acquisition framework and drivers; - Hardware crypto device drivers; - Device frequency scaling framework; - DMA engine subsystem; - EDAC drivers; - GPU drivers; - HID subsystem; - Hardware monitoring drivers; - I2C subsystem; - IIO subsystem; - IIO ADC drivers; - InfiniBand drivers; - Input Device core drivers; - Multiple devices driver; - Media drivers; - Network drivers; - Mellanox network drivers; - PCI subsystem; - PHY drivers; - Pin controllers subsystem; - x86 platform drivers; - Power supply drivers; - Powercap sysfs driver; - Voltage and Current Regulator drivers; - S/390 drivers; - ASPEED SoC drivers; - SPI subsystem; - small TFT LCD display modules; - Media staging drivers; - USB Gadget drivers; - vDPA drivers; - VFIO drivers; - Framebuffer layer; - Xen hypervisor drivers; - BTRFS file system; - Ceph distributed file sy…

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CVE-2025-38492 — netfs: Fix race between cache write completion and ALL_QUEUED being set

USN-7879-1 — linux, linux-aws, linux-gcp, linux-hwe-6.14, linux-oracle, linux-realtime vulnerabilities