Kernel: BPF unwind pads, debugfs fixes, Rust SPDM

Kernel development for the day centered on large subsystem series and two security fixes. Activity covered BPF exception paths, RISC-V IOMMU enablement, scheduler steal handling, and filesystem I/O conversion.

BPF unwind runs exception cleanup landing pads

A v6 21-patch series for bpf-next adds verifier and JIT support so bpf_unwind() executes LLVM cleanup landing pads. The work enables resource release for Rust panic paths inside BPF programs. Four participants exchanged 55 messages on the proposal.

debugfs string paths fix UAF and double-free

A patch series corrects use-after-free and double-free bugs in the debugfs_str read and write paths. The changes rely on RCU and inode_lock and carry a stable Cc. Three participants discussed the fix in 11 messages.

Rust SPDM requester reaches v4

A 22-patch v4 series supplies a Rust implementation of an SPDM requester plus supporting X.509 and crypto updates. The code targets PCIe CMA device authentication. One participant posted the series to linux-kernel.

RISC-V IOMMU gains MSI remapping and VFIO

A v6 16-patch series enables IMSIC MSI remapping and iommufd support for the RISC-V IOMMU. The changes turn on IOMMU_DMA and VFIO by default. Three participants reviewed the work across 24 messages.

Steal governor preferred CPUs merge into tip

The v14 13-patch series introducing preferred CPUs and steal-driven vCPU backoff was merged into tip/sched/core. Two participants discussed the scheduler changes over 25 messages. The series gives finer control of vCPU placement under steal time.

Accelerated AES modes move into lib/crypto

A v2 20-patch series migrates x86 and RISC-V accelerated AES mode implementations into the shared crypto library. The move eliminates duplication and enables the optimizations by default. One participant submitted the series.

ext4 buffered I/O converts to iomap

The v6 31-patch series continues converting ext4 regular-file buffered I/O from buffer_head to iomap. It addresses ordering, i_disksize, and data=ordered issues. Three participants examined the series in 23 messages.

kobject_uevent OOB read patched

A patch fixes an out-of-bounds read in kobject_action_type() caused by a strncmp length mismatch on a user buffer that may contain an embedded NUL. Two participants exchanged two messages on the correction.