BPF verifier rewrite, device trust, and kernel fixes

A major BPF verifier redesign led kernel discussion, alongside device trust controls for confidential computing and several memory safety fixes. Coverage infrastructure and inode reclaim work also advanced.

BPF verifier switches to state joining

A 45-patch series on bpf-next proposes rewriting the BPF verifier to join states at control-flow merges rather than enumerating paths. The change replaces path exploration with fixpoint analysis over the CFG, which the authors say would accept hundreds of previously rejected complex and Rust programs. Discussion involves three participants refining the large redesign.

Library fixes for maple tree and rhashtable

A four-patch series addresses a maple_tree RCU NULL dereference and an rhashtable deadlock when kvmalloc is called with GFP_ATOMIC under lock. Linus Torvalds described a recent kvmalloc change as buggy, prompting the corrections ahead of the 7.3 cycle. Seven participants reviewed the fixes on linux-kernel.

Device trust authorization before driver binding

A 17-patch series generalizes the PCI untrusted flag into cross-bus device trust levels (disabled, adversary, full) with userspace policy hooks. The work targets confidential computing by authorizing device trust before driver binding. Seven participants discussed the driver-core changes.

Sleepable user-memory kfuncs for BPF

Version 3 of an eight-patch series adds sleepable kfuncs bpf_user_anon_mmap, bpf_copy_to_user, and bpf_user_munmap. The set was accepted into bpf-next. Five participants refined the user-memory helpers.

Unified kernel coverage with Clang MC/DC

A 20-patch v2 series unifies gcov, KCOV, and LLVM coverage under kernel/coverage/ and adds Clang source-based MC/DC support while fixing noinstr violations. Three participants worked through the infrastructure changes.

Inode reclaim deadlock for metadata writeback

An RFC series fixes inode LRU reclamation deadlocks for I_METADATA_WRITEBACK on ext2, ext4-nojournal, fat, udf, and minix. Without the fix, unbounded inode cache growth can enable denial of service. The patches target stable kernels.

TCP IPv6 request-socket UAF fix

A netdev patch switches tcp_v6_reqsk_destructor to kfree_rcu for ireq->ipv6_opt, closing a use-after-free during request socket migration. Eight participants reviewed the RCU grace-period change.