CVE-2025-37747 — perf: Fix hang while freeing sigtrap event

Affected: Linux

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

perf: Fix hang while freeing sigtrap event

Perf can hang while freeing a sigtrap event if a related deferred signal hadn't managed to be sent before the file got closed:

perf_event_overflow() task_work_add(perf_pending_task)

fput() task_work_add(____fput())

task_work_run() ____fput() perf_release() perf_event_release_kernel() _free_event() perf_pending_task_sync() task_work_cancel() -> FAILED rcuwait_wait_event()

Once task_work_run() is running, the list of pending callbacks is removed from the task_struct and from this point on task_work_cancel() can't remove any pending and not yet started work items, hence the task_work_cancel() failure and the hang on rcuwait_wait_event().

Task work could be changed to remove one work at a time, so a work running on the current task can always cancel a pending one, however the wait / wake design is still subject to inverted dependencies when remote targets are involved, as pictured by Oleg:

T1 T2

fd = perf_event_open(pid => T2->pid); fd = perf_event_open(pid => T1->pid); close(fd) close(fd) <IRQ> <IRQ> perf_event_overflow() perf_event_overflow()…

USN-7594-1 — linux, linux-gcp, linux-raspi, linux-realtime vulnerabilities

Affected: Ubuntu:25.04: linux, Ubuntu:25.04: linux-gcp, Ubuntu:25.04: linux-raspi, Ubuntu:25.04: linux-realtime

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: - ARM32 architecture; - ARM64 architecture; - PowerPC architecture; - RISC-V architecture; - User-Mode Linux (UML); - x86 architecture; - Block layer subsystem; - Cryptographic API; - Compute Acceleration Framework; - ACPI drivers; - Serial ATA and Parallel ATA drivers; - Drivers core; - Ublk userspace block driver; - Bluetooth drivers; - Bus devices; - TPM device driver; - Clock framework and drivers; - CPU frequency scaling framework; - Buffer Sharing and Synchronization framework; - DMA engine subsystem; - GPU drivers; - HID subsystem; - HSI subsystem; - I2C subsystem; - I3C subsystem; - IIO subsystem; - InfiniBand drivers; - IOMMU subsystem; - IRQ chip drivers; - MCB driver; - Multiple devices driver; - Media drivers; - MemoryStick subsystem; - Multifunction device drivers; - Microchip PCI driver; - Intel Management Engine Interface driver; - PCI Endpoint Test driver; - MTD block device drivers; - Network drivers; - Ethernet bonding driver; - Mellanox network drivers; - STMicroelectronics network drivers; - NTB driver; - NVME drivers; - PCI subsystem; - Synopsys DesignWare PCIe PMU; - Mellanox platform drivers; - PWM drivers; - Remote Processor subsystem; - S/390 drivers; - SCSI subsystem; -…

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CVE-2025-37747 — perf: Fix hang while freeing sigtrap event

USN-7594-1 — linux, linux-gcp, linux-raspi, linux-realtime vulnerabilities