kernel/linux.git/arch/s390, branch master

s390/mm: Fix phys_to_folio() usage in do_secure_storage_access()

2026-04-28T12:45:03+00:00

In case of a Secure-Storage-Access exception the effective aka virtual address which caused the exception is contained within the TEID. do_secure_storage_access() incorrectly uses phys_to_folio() instead of virt_to_folio() to translate the virtual address to the corresponding folio. Fix this by using virt_to_folio() instead of phys_to_folio(). Fixes: 084ea4d611a3 ("s390/mm: add (non)secure page access exceptions handlers") Reviewed-by: Christian Borntraeger Reviewed-by: Claudio Imbrenda Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/debug: Reject zero-length input in debug_input_flush_fn()

2026-04-28T12:45:02+00:00

debug_input_flush_fn() always copies one byte from the userspace buffer with copy_from_user() regardless of the supplied write length. A zero-length write therefore reads one byte beyond the caller's buffer. If the stale byte happens to be '-' or a digit the debug log is silently flushed. With an unmapped buffer the call returns -EFAULT. Reject zero-length writes before copying from userspace. Cc: stable@vger.kernel.org # v5.10+ Acked-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Alexander Gordeev

s390/debug: Reject zero-length input before trimming a newline

2026-04-28T12:45:02+00:00

debug_get_user_string() duplicates the userspace buffer with memdup_user_nul() and then unconditionally looks at buffer[user_len - 1] to strip a trailing newline. A zero-length write reaches this helper unchanged, so the newline trim reads before the start of the allocated buffer. Reject empty writes before accessing the last input byte. Fixes: 66a464dbc8e0 ("[PATCH] s390: debug feature changes") Cc: stable@vger.kernel.org Signed-off-by: Pengpeng Hou Reviewed-by: Benjamin Block Reviewed-by: Vasily Gorbik Tested-by: Vasily Gorbik Link: https://lore.kernel.org/r/20260417073530.96002-1-pengpeng@iscas.ac.cn Signed-off-by: Vasily Gorbik Signed-off-by: Alexander Gordeev

Merge tag 's390-7.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2026-04-22T18:13:45+00:00

Pull s390 updates from Vasily Gorbik: - Add support for CONFIG_PAGE_TABLE_CHECK and enable it in debug_defconfig. s390 can only tell user from kernel PTEs via the mm, so mm_struct is now passed into pxx_user_accessible_page() callbacks - Expose the PCI function UID as an arch-specific slot attribute in sysfs so a function can be identified by its user-defined id while still in standby. Introduces a generic ARCH_PCI_SLOT_GROUPS hook in drivers/pci/slot.c - Refresh s390 PCI documentation to reflect current behavior and cover previously undocumented sysfs attributes - zcrypt device driver cleanup series: consistent field types, clearer variable naming, a kernel-doc warning fix, and a comment explaining the intentional synchronize_rcu() in pkey_handler_register() - Provide an s390 arch_raw_cpu_ptr() that avoids the detour via get_lowcore() using alternatives, shrinking defconfig by ~27 kB - Guard identity-base randomization with kaslr_enabled() so nokaslr keeps the identity mapping at 0 even with RANDOMIZE_IDENTITY_BASE=y - Build S390_MODULES_SANITY_TEST as a module only by requiring KUNIT && m, since built-in would not exercise module loading - Remove the permanently commented-out HMCDRV_DEV_CLASS create_class() code in the hmcdrv driver - Drop stale ident_map_size extern conflicting with asm/page.h * tag 's390-7.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/zcrypt: Fix warning about wrong kernel doc comment PCI: s390: Expose the UID as an arch specific PCI slot attribute docs: s390/pci: Improve and update PCI documentation s390/pkey: Add comment about synchronize_rcu() to pkey base s390/hmcdrv: Remove commented out code s390/zcrypt: Slight rework on the agent_id field s390/zcrypt: Explicitly use a card variable in _zcrypt_send_cprb s390/zcrypt: Rework MKVP fields and handling s390/zcrypt: Make apfs a real unsigned int field s390/zcrypt: Rework domain processing within zcrypt device driver s390/zcrypt: Move inline function rng_type6cprb_msgx from header to code s390/percpu: Provide arch_raw_cpu_ptr() s390: Enable page table check for debug_defconfig s390/pgtable: Add s390 support for page table check s390/pgtable: Use set_pmd_bit() to invalidate PMD entry mm/page_table_check: Pass mm_struct to pxx_user_accessible_page() s390/boot: Respect kaslr_enabled() for identity randomization s390/Kconfig: Make modules sanity test a module-only option s390/setup: Drop stale ident_map_size declaration

Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

2026-04-17T22:58:22+00:00

Pull bpf fixes from Alexei Starovoitov: "Most of the diff stat comes from Xu Kuohai's fix to emit ENDBR/BTI, since all JITs had to be touched to move constant blinding out and pass bpf_verifier_env in. - Fix use-after-free in arena_vm_close on fork (Alexei Starovoitov) - Dissociate struct_ops program with map if map_update fails (Amery Hung) - Fix out-of-range and off-by-one bugs in arm64 JIT (Daniel Borkmann) - Fix precedence bug in convert_bpf_ld_abs alignment check (Daniel Borkmann) - Fix arg tracking for imprecise/multi-offset in BPF_ST/STX insns (Eduard Zingerman) - Copy token from main to subprogs to fix missing kallsyms (Eduard Zingerman) - Prevent double close and leak of btf objects in libbpf (Jiri Olsa) - Fix af_unix null-ptr-deref in sockmap (Michal Luczaj) - Fix NULL deref in map_kptr_match_type for scalar regs (Mykyta Yatsenko) - Avoid unnecessary IPIs. Remove redundant bpf_flush_icache() in arm64 and riscv JITs (Puranjay Mohan) - Fix out of bounds access. Validate node_id in arena_alloc_pages() (Puranjay Mohan) - Reject BPF-to-BPF calls and callbacks in arm32 JIT (Puranjay Mohan) - Refactor all JITs to pass bpf_verifier_env to emit ENDBR/BTI for indirect jump targets on x86-64, arm64 JITs (Xu Kuohai) - Allow UTF-8 literals in bpf_bprintf_prepare() (Yihan Ding)" * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (32 commits) bpf, arm32: Reject BPF-to-BPF calls and callbacks in the JIT bpf: Dissociate struct_ops program with map if map_update fails bpf: Validate node_id in arena_alloc_pages() libbpf: Prevent double close and leak of btf objects selftests/bpf: cover UTF-8 trace_printk output bpf: allow UTF-8 literals in bpf_bprintf_prepare() selftests/bpf: Reject scalar store into kptr slot bpf: Fix NULL deref in map_kptr_match_type for scalar regs bpf: Fix precedence bug in convert_bpf_ld_abs alignment check bpf, arm64: Emit BTI for indirect jump target bpf, x86: Emit ENDBR for indirect jump targets bpf: Add helper to detect indirect jump targets bpf: Pass bpf_verifier_env to JIT bpf: Move constants blinding out of arch-specific JITs bpf, sockmap: Take state lock for af_unix iter bpf, sockmap: Fix af_unix null-ptr-deref in proto update selftests/bpf: Extend bpf_iter_unix to attempt deadlocking bpf, sockmap: Fix af_unix iter deadlock bpf, sockmap: Annotate af_unix sock:: Sk_state data-races selftests/bpf: verify kallsyms entries for token-loaded subprograms ...

Merge tag 'integrity-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

2026-04-17T22:42:01+00:00

Pull integrity updates from Mimi Zohar: "There are two main changes, one feature removal, some code cleanup, and a number of bug fixes. Main changes: - Detecting secure boot mode was limited to IMA. Make detecting secure boot mode accessible to EVM and other LSMs - IMA sigv3 support was limited to fsverity. Add IMA sigv3 support for IMA regular file hashes and EVM portable signatures Remove: - Remove IMA support for asychronous hash calculation originally added for hardware acceleration Cleanup: - Remove unnecessary Kconfig CONFIG_MODULE_SIG and CONFIG_KEXEC_SIG tests - Add descriptions of the IMA atomic flags Bug fixes: - Like IMA, properly limit EVM "fix" mode - Define and call evm_fix_hmac() to update security.evm - Fallback to using i_version to detect file change for filesystems that do not support STATX_CHANGE_COOKIE - Address missing kernel support for configured (new) TPM hash algorithms - Add missing crypto_shash_final() return value" * tag 'integrity-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: evm: Enforce signatures version 3 with new EVM policy 'bit 3' integrity: Allow sigv3 verification on EVM_XATTR_PORTABLE_DIGSIG ima: add support to require IMA sigv3 signatures ima: add regular file data hash signature version 3 support ima: Define asymmetric_verify_v3() to verify IMA sigv3 signatures ima: remove buggy support for asynchronous hashes integrity: Eliminate weak definition of arch_get_secureboot() ima: Add code comments to explain IMA iint cache atomic_flags ima_fs: Correctly create securityfs files for unsupported hash algos ima: check return value of crypto_shash_final() in boot aggregate ima: Define and use a digest_size field in the ima_algo_desc structure powerpc/ima: Drop unnecessary check for CONFIG_MODULE_SIG ima: efi: Drop unnecessary check for CONFIG_MODULE_SIG/CONFIG_KEXEC_SIG ima: fallback to using i_version to detect file change evm: fix security.evm for a file with IMA signature s390: Drop unnecessary CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT evm: Don't enable fix mode when secure boot is enabled integrity: Make arch_ima_get_secureboot integrity-wide

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2026-04-17T14:18:03+00:00

Pull kvm updates from Paolo Bonzini: "Arm: - Add support for tracing in the standalone EL2 hypervisor code, which should help both debugging and performance analysis. This uses the new infrastructure for 'remote' trace buffers that can be exposed by non-kernel entities such as firmware, and which came through the tracing tree - Add support for GICv5 Per Processor Interrupts (PPIs), as the starting point for supporting the new GIC architecture in KVM - Finally add support for pKVM protected guests, where pages are unmapped from the host as they are faulted into the guest and can be shared back from the guest using pKVM hypercalls. Protected guests are created using a new machine type identifier. As the elusive guestmem has not yet delivered on its promises, anonymous memory is also supported This is only a first step towards full isolation from the host; for example, the CPU register state and DMA accesses are not yet isolated. Because this does not really yet bring fully what it promises, it is hidden behind CONFIG_ARM_PKVM_GUEST + 'kvm-arm.mode=protected', and also triggers TAINT_USER when a VM is created. Caveat emptor - Rework the dreaded user_mem_abort() function to make it more maintainable, reducing the amount of state being exposed to the various helpers and rendering a substantial amount of state immutable - Expand the Stage-2 page table dumper to support NV shadow page tables on a per-VM basis - Tidy up the pKVM PSCI proxy code to be slightly less hard to follow - Fix both SPE and TRBE in non-VHE configurations so that they do not generate spurious, out of context table walks that ultimately lead to very bad HW lockups - A small set of patches fixing the Stage-2 MMU freeing in error cases - Tighten-up accepted SMC immediate value to be only #0 for host SMCCC calls - The usual cleanups and other selftest churn LoongArch: - Use CSR_CRMD_PLV for kvm_arch_vcpu_in_kernel() - Add DMSINTC irqchip in kernel support RISC-V: - Fix steal time shared memory alignment checks - Fix vector context allocation leak - Fix array out-of-bounds in pmu_ctr_read() and pmu_fw_ctr_read_hi() - Fix double-free of sdata in kvm_pmu_clear_snapshot_area() - Fix integer overflow in kvm_pmu_validate_counter_mask() - Fix shift-out-of-bounds in make_xfence_request() - Fix lost write protection on huge pages during dirty logging - Split huge pages during fault handling for dirty logging - Skip CSR restore if VCPU is reloaded on the same core - Implement kvm_arch_has_default_irqchip() for KVM selftests - Factored-out ISA checks into separate sources - Added hideleg to struct kvm_vcpu_config - Factored-out VCPU config into separate sources - Support configuration of per-VM HGATP mode from KVM user space s390: - Support for ESA (31-bit) guests inside nested hypervisors - Remove restriction on memslot alignment, which is not needed anymore with the new gmap code - Fix LPSW/E to update the bear (which of course is the breaking event address register) x86: - Shut up various UBSAN warnings on reading module parameter before they were initialized - Don't zero-allocate page tables that are used for splitting hugepages in the TDP MMU, as KVM is guaranteed to set all SPTEs in the page table and thus write all bytes - As an optimization, bail early when trying to unsync 4KiB mappings if the target gfn can just be mapped with a 2MiB hugepage x86 generic: - Copy single-chunk MMIO write values into struct kvm_vcpu (more precisely struct kvm_mmio_fragment) to fix use-after-free stack bugs where KVM would dereference stack pointer after an exit to userspace - Clean up and comment the emulated MMIO code to try to make it easier to maintain (not necessarily "easy", but "easier") - Move VMXON+VMXOFF and EFER.SVME toggling out of KVM (not *all* of VMX and SVM enabling) as it is needed for trusted I/O - Advertise support for AVX512 Bit Matrix Multiply (BMM) instructions - Immediately fail the build if a required #define is missing in one of KVM's headers that is included multiple times - Reject SET_GUEST_DEBUG with -EBUSY if there's an already injected exception, mostly to prevent syzkaller from abusing the uAPI to trigger WARNs, but also because it can help prevent userspace from unintentionally crashing the VM - Exempt SMM from CPUID faulting on Intel, as per the spec - Misc hardening and cleanup changes x86 (AMD): - Fix and optimize IRQ window inhibit handling for AVIC; make it per-vCPU so that KVM doesn't prematurely re-enable AVIC if multiple vCPUs have to-be-injected IRQs - Clean up and optimize the OSVW handling, avoiding a bug in which KVM would overwrite state when enabling virtualization on multiple CPUs in parallel. This should not be a problem because OSVW should usually be the same for all CPUs - Drop a WARN in KVM_MEMORY_ENCRYPT_REG_REGION where KVM complains about a "too large" size based purely on user input - Clean up and harden the pinning code for KVM_MEMORY_ENCRYPT_REG_REGION - Disallow synchronizing a VMSA of an already-launched/encrypted vCPU, as doing so for an SNP guest will crash the host due to an RMP violation page fault - Overhaul KVM's APIs for detecting SEV+ guests so that VM-scoped queries are required to hold kvm->lock, and enforce it by lockdep. Fix various bugs where sev_guest() was not ensured to be stable for the whole duration of a function or ioctl - Convert a pile of kvm->lock SEV code to guard() - Play nicer with userspace that does not enable KVM_CAP_EXCEPTION_PAYLOAD, for which KVM needs to set CR2 and DR6 as a response to ioctls such as KVM_GET_VCPU_EVENTS (even if the payload would end up in EXITINFO2 rather than CR2, for example). Only set CR2 and DR6 when consumption of the payload is imminent, but on the other hand force delivery of the payload in all paths where userspace retrieves CR2 or DR6 - Use vcpu->arch.cr2 when updating vmcb12's CR2 on nested #VMEXIT instead of vmcb02->save.cr2. The value is out of sync after a save/restore or after a #PF is injected into L2 - Fix a class of nSVM bugs where some fields written by the CPU are not synchronized from vmcb02 to cached vmcb12 after VMRUN, and so are not up-to-date when saved by KVM_GET_NESTED_STATE - Fix a class of bugs where the ordering between KVM_SET_NESTED_STATE and KVM_SET_{S}REGS could cause vmcb02 to be incorrectly initialized after save+restore - Add a variety of missing nSVM consistency checks - Fix several bugs where KVM failed to correctly update VMCB fields on nested #VMEXIT - Fix several bugs where KVM failed to correctly synthesize #UD or #GP for SVM-related instructions - Add support for save+restore of virtualized LBRs (on SVM) - Refactor various helpers and macros to improve clarity and (hopefully) make the code easier to maintain - Aggressively sanitize fields when copying from vmcb12, to guard against unintentionally allowing L1 to utilize yet-to-be-defined features - Fix several bugs where KVM botched rAX legality checks when emulating SVM instructions. There are remaining issues in that KVM doesn't handle size prefix overrides for 64-bit guests - Fail emulation of VMRUN/VMLOAD/VMSAVE if mapping vmcb12 fails instead of somewhat arbitrarily synthesizing #GP (i.e. don't double down on AMD's architectural but sketchy behavior of generating #GP for "unsupported" addresses) - Cache all used vmcb12 fields to further harden against TOCTOU bugs x86 (Intel): - Drop obsolete branch hint prefixes from the VMX instruction macros - Use ASM_INPUT_RM() in __vmcs_writel() to coerce clang into using a register input when appropriate - Code cleanups guest_memfd: - Don't mark guest_memfd folios as accessed, as guest_memfd doesn't support reclaim, the memory is unevictable, and there is no storage to write back to LoongArch selftests: - Add KVM PMU test cases s390 selftests: - Enable more memory selftests x86 selftests: - Add support for Hygon CPUs in KVM selftests - Fix a bug in the MSR test where it would get false failures on AMD/Hygon CPUs with exactly one of RDPID or RDTSCP - Add an MADV_COLLAPSE testcase for guest_memfd as a regression test for a bug where the kernel would attempt to collapse guest_memfd folios against KVM's will" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (373 commits) KVM: x86: use inlines instead of macros for is_sev_*guest x86/virt: Treat SVM as unsupported when running as an SEV+ guest KVM: SEV: Goto an existing error label if charging misc_cg for an ASID fails KVM: SVM: Move lock-protected allocation of SEV ASID into a separate helper KVM: SEV: use mutex guard in snp_handle_guest_req() KVM: SEV: use mutex guard in sev_mem_enc_unregister_region() KVM: SEV: use mutex guard in sev_mem_enc_ioctl() KVM: SEV: use mutex guard in snp_launch_update() KVM: SEV: Assert that kvm->lock is held when querying SEV+ support KVM: SEV: Document that checking for SEV+ guests when reclaiming memory is "safe" KVM: SEV: Hide "struct kvm_sev_info" behind CONFIG_KVM_AMD_SEV=y KVM: SEV: WARN on unhandled VM type when initializing VM KVM: LoongArch: selftests: Add PMU overflow interrupt test KVM: LoongArch: selftests: Add basic PMU event counting test KVM: LoongArch: selftests: Add cpucfg read/write helpers LoongArch: KVM: Add DMSINTC inject msi to vCPU LoongArch: KVM: Add DMSINTC device support LoongArch: KVM: Make vcpu_is_preempted() as a macro rather than function LoongArch: KVM: Move host CSR_GSTAT save and restore in context switch LoongArch: KVM: Move host CSR_EENTRY save and restore in context switch ...

Merge tag 'mm-nonmm-stable-2026-04-15-04-20' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-04-17T03:11:56+00:00

Pull non-MM updates from Andrew Morton: - "pid: make sub-init creation retryable" (Oleg Nesterov) Make creation of init in a new namespace more robust by clearing away some historical cruft which is no longer needed. Also some documentation fixups - "selftests/fchmodat2: Error handling and general" (Mark Brown) Fix and a cleanup for the fchmodat2() syscall selftest - "lib: polynomial: Move to math/ and clean up" (Andy Shevchenko) - "hung_task: Provide runtime reset interface for hung task detector" (Aaron Tomlin) Give administrators the ability to zero out /proc/sys/kernel/hung_task_detect_count - "tools/getdelays: use the static UAPI headers from tools/include/uapi" (Thomas Weißschuh) Teach getdelays to use the in-kernel UAPI headers rather than the system-provided ones - "watchdog/hardlockup: Improvements to hardlockup" (Mayank Rungta) Several cleanups and fixups to the hardlockup detector code and its documentation - "lib/bch: fix undefined behavior from signed left-shifts" (Josh Law) A couple of small/theoretical fixes in the bch code - "ocfs2/dlm: fix two bugs in dlm_match_regions()" (Junrui Luo) - "cleanup the RAID5 XOR library" (Christoph Hellwig) A quite far-reaching cleanup to this code. I can't do better than to quote Christoph: "The XOR library used for the RAID5 parity is a bit of a mess right now. The main file sits in crypto/ despite not being cryptography and not using the crypto API, with the generic implementations sitting in include/asm-generic and the arch implementations sitting in an asm/ header in theory. The latter doesn't work for many cases, so architectures often build the code directly into the core kernel, or create another module for the architecture code. Change this to a single module in lib/ that also contains the architecture optimizations, similar to the library work Eric Biggers has done for the CRC and crypto libraries later. After that it changes to better calling conventions that allow for smarter architecture implementations (although none is contained here yet), and uses static_call to avoid indirection function call overhead" - "lib/list_sort: Clean up list_sort() scheduling workarounds" (Kuan-Wei Chiu) Clean up this library code by removing a hacky thing which was added for UBIFS, which UBIFS doesn't actually need - "Fix bugs in extract_iter_to_sg()" (Christian Ehrhardt) Fix a few bugs in the scatterlist code, add in-kernel tests for the now-fixed bugs and fix a leak in the test itself - "kdump: Enable LUKS-encrypted dump target support in ARM64 and PowerPC" (Coiby Xu) Enable support of the LUKS-encrypted device dump target on arm64 and powerpc - "ocfs2: consolidate extent list validation into block read callbacks" (Joseph Qi) Cleanup, simplify, and make more robust ocfs2's validation of extent list fields (Kernel test robot loves mounting corrupted fs images!) * tag 'mm-nonmm-stable-2026-04-15-04-20' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (127 commits) ocfs2: validate group add input before caching ocfs2: validate bg_bits during freefrag scan ocfs2: fix listxattr handling when the buffer is full doc: watchdog: fix typos etc update Sean's email address ocfs2: use get_random_u32() where appropriate ocfs2: split transactions in dio completion to avoid credit exhaustion ocfs2: remove redundant l_next_free_rec check in __ocfs2_find_path() ocfs2: validate extent block list fields during block read ocfs2: remove empty extent list check in ocfs2_dx_dir_lookup_rec() ocfs2: validate dx_root extent list fields during block read ocfs2: fix use-after-free in ocfs2_fault() when VM_FAULT_RETRY ocfs2: handle invalid dinode in ocfs2_group_extend .get_maintainer.ignore: add Askar ocfs2: validate bg_list extent bounds in discontig groups checkpatch: exclude forward declarations of const structs tools/accounting: handle truncated taskstats netlink messages taskstats: set version in TGID exit notifications ocfs2/heartbeat: fix slot mapping rollback leaks on error paths arm64,ppc64le/kdump: pass dm-crypt keys to kdump kernel ...

bpf: Pass bpf_verifier_env to JIT

2026-04-16T14:03:40+00:00

Pass bpf_verifier_env to bpf_int_jit_compile(). The follow-up patch will use env->insn_aux_data in the JIT stage to detect indirect jump targets. Since bpf_prog_select_runtime() can be called by cbpf and lib/test_bpf.c code without verifier, introduce helper __bpf_prog_select_runtime() to accept the env parameter. Remove the call to bpf_prog_select_runtime() in bpf_prog_load(), and switch to call __bpf_prog_select_runtime() in the verifier, with env variable passed. The original bpf_prog_select_runtime() is preserved for cbpf and lib/test_bpf.c, where env is NULL. Now all constants blinding calls are moved into the verifier, except the cbpf and lib/test_bpf.c cases. The instructions arrays are adjusted by bpf_patch_insn_data() function for normal cases, so there is no need to call adjust_insn_arrays() in bpf_jit_blind_constants(). Remove it. Reviewed-by: Anton Protopopov # v8 Reviewed-by: Emil Tsalapatis # v12 Acked-by: Hengqi Chen # v14 Signed-off-by: Xu Kuohai Link: https://lore.kernel.org/r/20260416064341.151802-3-xukuohai@huaweicloud.com Signed-off-by: Alexei Starovoitov

bpf: Move constants blinding out of arch-specific JITs

2026-04-16T14:03:40+00:00

During the JIT stage, constants blinding rewrites instructions but only rewrites the private instruction copy of the JITed subprog, leaving the global env->prog->insnsi and env->insn_aux_data untouched. This causes a mismatch between subprog instructions and the global state, making it difficult to use the global data in the JIT. To avoid this mismatch, and given that all arch-specific JITs already support constants blinding, move it to the generic verifier code, and switch to rewrite the global env->prog->insnsi with the global states adjusted, as other rewrites in the verifier do. This removes the constants blinding calls in each JIT, which are largely duplicated code across architectures. Since constants blinding is only required for JIT, and there are two JIT entry functions, jit_subprogs() for BPF programs with multiple subprogs and bpf_prog_select_runtime() for programs with no subprogs, move the constants blinding invocation into these two functions. In the verifier path, bpf_patch_insn_data() is used to keep global verifier auxiliary data in sync with patched instructions. A key question is whether this global auxiliary data should be restored on the failure path. Besides instructions, bpf_patch_insn_data() adjusts: - prog->aux->poke_tab - env->insn_array_maps - env->subprog_info - env->insn_aux_data For prog->aux->poke_tab, it is only used by JIT or only meaningful after JIT succeeds, so it does not need to be restored on the failure path. For env->insn_array_maps, when JIT fails, programs using insn arrays are rejected by bpf_insn_array_ready() due to missing JIT addresses. Hence, env->insn_array_maps is only meaningful for JIT and does not need to be restored. For subprog_info, if jit_subprogs fails and CONFIG_BPF_JIT_ALWAYS_ON is not enabled, kernel falls back to interpreter. In this case, env->subprog_info is used to determine subprogram stack depth. So it must be restored on failure. For env->insn_aux_data, it is freed by clear_insn_aux_data() at the end of bpf_check(). Before freeing, clear_insn_aux_data() loops over env->insn_aux_data to release jump targets recorded in it. The loop uses env->prog->len as the array length, but this length no longer matches the actual size of the adjusted env->insn_aux_data array after constants blinding. To address it, a simple approach is to keep insn_aux_data as adjusted after failure, since it will be freed shortly, and record its actual size for the loop in clear_insn_aux_data(). But since clear_insn_aux_data() uses the same index to loop over both env->prog->insnsi and env->insn_aux_data, this approach results in incorrect index for the insnsi array. So an alternative approach is adopted: clone the original env->insn_aux_data before blinding and restore it after failure, similar to env->prog. For classic BPF programs, constants blinding works as before since it is still invoked from bpf_prog_select_runtime(). Reviewed-by: Anton Protopopov # v8 Reviewed-by: Hari Bathini # powerpc jit Reviewed-by: Pu Lehui # riscv jit Acked-by: Hengqi Chen # loongarch jit Signed-off-by: Xu Kuohai Link: https://lore.kernel.org/r/20260416064341.151802-2-xukuohai@huaweicloud.com Signed-off-by: Alexei Starovoitov