kernel/linux.git/arch, branch v6.1.182

x86/bugs: Make Safe-RET robust against interrupt injection

2026-08-07T06:09:27+00:00

commit 7e7f81cf6f5ca3311e526308f55d7c54d3ba71f9 upstream. An attacker injecting interrupts while the Safe-RET mitigation executes on machines affected by SRSO can neutralize the safe return sequence, potentially leading to data leakage through speculative execution. Fixup register state as if the Safe-RET sequence executed successfully by "emulating" it, in a manner of speaking, and avoid executing a RET instruction after returning from the interrupt. Co-developed-by: David Kaplan Signed-off-by: David Kaplan Signed-off-by: Borislav Petkov (AMD) Signed-off-by: Wenkuan Wang Signed-off-by: Greg Kroah-Hartman

Revert "x86/bugs: Make Safe-RET robust against interrupt injection"

2026-08-07T06:09:27+00:00

This reverts commit 95b08cdd603fe79d2e9d5212fbb13d577c835f4f which is commit 7e7f81cf6f5ca3311e526308f55d7c54d3ba71f9 upstream. It was incorrect, a more correct fix will be applied next. Signed-off-by: Greg Kroah-Hartman

x86/bugs: Make Safe-RET robust against interrupt injection

2026-08-06T17:23:14+00:00

perf/x86/amd/core: Always use the NMI latency mitigation

2026-07-24T13:55:19+00:00

commit 73a4c02f94a98d94480c3e5c81450215a4da05ba upstream. Commit df4d29732fda ("perf/x86/amd: Change/fix NMI latency mitigation to use a timestamp") fixed handling of late-arriving NMIs but limited the mitigation to processors having X86_FEATURE_PERFCTR_CORE. However, it is unclear if processors without this feature are also affected. When Mediated vPMU is enabled on affected hardware, it is also possible to bypass the fix inside KVM guests if X86_FEATURE_PERFCTR_CORE is removed from the guest CPUID (e.g. using "-cpu host,-perfctr-core" with QEMU). Hence, use the mitigation at all times. Fixes: df4d29732fda ("perf/x86/amd: Change/fix NMI latency mitigation to use a timestamp") Signed-off-by: Sandipan Das Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/29a3c970da289ab8f24282933bdb36545c0403e8.1780325517.git.sandipan.das@amd.com Signed-off-by: Greg Kroah-Hartman

KVM: Move kvm_io_bus_get_dev() locking responsibilities to callers

2026-07-24T13:55:18+00:00

commit 3a07249981629ace483ebbef81ef6b34c2d2afec upstream. kvm_io_bus_get_dev() returns a device that is only matched by the address, and nothing else. This can cause a lifetime issue if the matched device is not the expected type, as by the time the caller can introspect the object, it might be gone (the srcu lock having been dropped). Given that there is only a single user of this helper, the simplest option is to move the locking responsibility to the caller, which can keep the srcu lock held for as long as it wants. Note that this aligns with other kvm_io_bus*() helpers, which already require the srcu lock to be held by the callers. Reported-by: Will Deacon Fixes: 8a39d00670f07 ("KVM: kvm_io_bus: Add kvm_io_bus_get_dev() call") Link: https://lore.kernel.org/all/20260626111344.802555-1-maz@kernel.org Cc: stable@vger.kernel.org Reviewed-by: Oliver Upton Link: https://patch.msgid.link/20260627105105.1005990-1-maz@kernel.org Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman

powerpc/spufs: fix out-of-bounds access in spufs_mem_mmap_access()

2026-07-24T13:55:10+00:00

commit 47b87f469a35b5ffc81c16eee6b13a9b6c8d55c6 upstream. spufs_mem_mmap_access() computes the local store offset as address - vma->vm_start, but bounds-checks it against vma->vm_end instead of the local store size. On 64-bit, offset is always well below vma->vm_end, so the clamp never fires and len stays unbounded against the LS_SIZE buffer returned by ctx->ops->get_ls(). Reject offsets at or beyond LS_SIZE and clamp len to the remaining space, mirroring the guard already used by spufs_mem_mmap_fault() and spufs_ps_fault(). Fixes: a352894d0705 ("spufs: use new vm_ops->access to allow local state access from gdb") Reported-by: Yuhao Jiang Cc: stable@vger.kernel.org Signed-off-by: Junrui Luo Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/SYBPR01MB7881EE775E8B51C09F5A29E7AF152@SYBPR01MB7881.ausprd01.prod.outlook.com Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: fix memory leak on krealloc failure in papr_init

2026-07-24T13:55:10+00:00

commit bd83c98b988d2c560531084e296dbfb530aff829 upstream. When krealloc() fails, free the original esi_buf before returning to avoid a memory leak. Fixes: 3c14b73454cf ("powerpc/pseries: Interface to represent PAPR firmware attributes") Cc: stable@vger.kernel.org Signed-off-by: Thorsten Blum Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260614142356.658212-2-thorsten.blum@linux.dev Signed-off-by: Greg Kroah-Hartman

riscv: Prevent NULL pointer dereference in machine_kexec_prepare()

2026-07-24T13:55:10+00:00

commit 81bbcff0c053c4f5c711c31a9b72fc492bd96c3f upstream. A NULL pointer dereference issue is noticed in riscv's machine_kexec_prepare(), where image->segment[i].buf might be NULL and copied unchecked. The NULL buf comes from ima_add_kexec_buffer(), where kbuf is added by kexec_add_buffer(), but kbuf.buffer is NULL, then it is copied without a check in machine_kexec_prepare(): kexec_file_load -> kimage_file_alloc_init() -> kimage_file_prepare_segments() -> ima_add_kexec_buffer() -> kexec_add_buffer() -> machine_kexec_prepare() -> memcpy() Address this by adding a check before the data copy attempt. Fixes: b7fb4d78a6ad ("RISC-V: use memcpy for kexec_file mode") Cc: stable@vger.kernel.org Closes: https://lore.kernel.org/kexec/CAO7dBbVftLUhd2qrh7hmijTB3PEPfZAhykCGqEfrPoOcSrrj-w@mail.gmail.com/ Acked-by: Baoquan He Acked-by: Pratyush Yadav Reviewed-by: Nutty Liu Signed-off-by: Tao Liu Link: https://patch.msgid.link/20260705232706.30265-2-ltao@redhat.com Signed-off-by: Paul Walmsley Signed-off-by: Greg Kroah-Hartman

LoongArch: Fix missing dirty page tracking in {pte,pmd}_wrprotect()

2026-07-24T13:55:08+00:00

commit 018e9828eb523c638fa3d9bdf0fd4956b74555b2 upstream. When hardware page table walker (PTW) is enabled on LoongArch, the CPU may set _PAGE_DIRTY directly in the page table entry during a write TLB miss, without going through the software TLB store handler. The software TLB store handler (tlbex.S:254) sets both _PAGE_DIRTY and_PAGE_MODIFIED together: ori t0, t0, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED) Since hardware PTW only sets _PAGE_DIRTY, the software-only bit, i.e. _PAGE_MODIFIED is left unchanged. This creates a window where a PTE has _PAGE_DIRTY set (hardware knows the page is dirty) but _PAGE_MODIFIED clear (software is unaware). When fork()/clone() triggers copy-on-write, __copy_present_ptes() calls pte_wrprotect(), which unconditionally clears both the _PAGE_WRITE and _PAGE_DIRTY bits: pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_DIRTY); Since _PAGE_MODIFIED was never set, the dirtiness information is lost completely. Subsequently, when memory pressure triggers page reclaim, page_mkclean() / try_to_unmap() sees the page as clean (i.e. pte_dirty() returns false) and the page may be freed without writeback, causing data corruption. Fix this by propagating the _PAGE_DIRTY bit to the _PAGE_MODIFIED bit in both pte_wrprotect() and pmd_wrprotect() before clearing writeable bits: if (pte_val(pte) & _PAGE_DIRTY) pte_val(pte) |= _PAGE_MODIFIED; The pmd_wrprotect() fix handles the CONFIG_TRANSPARENT_HUGEPAGE case, where pmd entries need the same treatment. This ensures the software dirty tracking bit (checked by pte_dirty() and pmd_dirty(), which read both the _PAGE_DIRTY and _PAGE_MODIFIED bits) is preserved across fork COW write-protection. The issue was found by the LTP madvise09 test case, which exercises page reclaim after "madvise(MADV_FREE), write and fork" operation sequence on private anonymous mappings. Cc: stable@vger.kernel.org Fixes: 09cfefb7fa70 ("LoongArch: Add memory management") Co-developed-by: Tianyang Zhang Signed-off-by: Tianyang Zhang Signed-off-by: Hongchen Zhang Signed-off-by: Huacai Chen Signed-off-by: Greg Kroah-Hartman

riscv: cacheinfo: Fix node reference leak in populate_cache_leaves

2026-07-24T13:55:02+00:00

commit bf4a195f063b0a0805c1417f6aad1dd32ea48f0f upstream. Currently, the while loop drops the reference to prev in each iteration. If the loop terminates early due to a break, the final of_node_put(np) correctly drops the reference to the current node. However, if the loop terminates naturally because np == NULL, calling of_node_put(np) is a no-op. This leaves the last valid node stored in prev without its reference dropped, resulting in a node reference leak. Fix this by changing the final `of_node_put(np)` to `of_node_put(prev)`. Fixes: 94f9bf118f1e ("RISC-V: Fix of_node_* refcount") Cc: stable@vger.kernel.org Assisted-by: Gemini:gemini-3.1-pro Signed-off-by: Zishun Yi Link: https://patch.msgid.link/20260509074040.1747800-1-vulab@iscas.ac.cn Signed-off-by: Paul Walmsley Signed-off-by: Greg Kroah-Hartman