From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: + maccess-return-erange-when-copy_from_kernel_nofault_allowed-fails.patch added to -mm tree Date: Wed, 27 May 2020 17:37:46 -0700 Message-ID: <20200528003746.sBIw5aD8x%akpm@linux-foundation.org> References: <20200522222217.ee14ad7eda7aab1e6697da6c@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:58760 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725267AbgE1Ahs (ORCPT ); Wed, 27 May 2020 20:37:48 -0400 In-Reply-To: <20200522222217.ee14ad7eda7aab1e6697da6c@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: ast@kernel.org, daniel@iogearbox.net, hch@lst.de, hpa@zytor.com, mhiramat@kernel.org, mingo@elte.hu, mm-commits@vger.kernel.org, tglx@linutronix.de The patch titled Subject: maccess: return -ERANGE when probe_kernel_read() fails has been added to the -mm tree. Its filename is maccess-return-erange-when-copy_from_kernel_nofault_allowed-fails.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/maccess-return-erange-when-copy_from_kernel_nofault_allowed-fails.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/maccess-return-erange-when-copy_from_kernel_nofault_allowed-fails.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Christoph Hellwig Subject: maccess: return -ERANGE when probe_kernel_read() fails Allow the callers to distinguish a real unmapped address vs a range that can't be probed. Link: http://lkml.kernel.org/r/20200521152301.2587579-24-hch@lst.de Signed-off-by: Christoph Hellwig Suggested-by: Masami Hiramatsu Reviewed-by: Masami Hiramatsu Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- mm/maccess.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) --- a/mm/maccess.c~maccess-return-erange-when-copy_from_kernel_nofault_allowed-fails +++ a/mm/maccess.c @@ -24,7 +24,7 @@ bool __weak probe_kernel_read_allowed(co long probe_kernel_read(void *dst, const void *src, size_t size) { if (!probe_kernel_read_allowed(src, size)) - return -EFAULT; + return -ERANGE; pagefault_disable(); probe_kernel_read_loop(dst, src, size, u64, Efault); @@ -68,7 +68,7 @@ long strncpy_from_kernel_nofault(char *d if (unlikely(count <= 0)) return 0; if (!probe_kernel_read_allowed(unsafe_addr, count)) - return -EFAULT; + return -ERANGE; pagefault_disable(); do { @@ -93,7 +93,8 @@ Efault: * @size: size of the data chunk * * Safely read from kernel address @src to the buffer at @dst. If a kernel - * fault happens, handle that and return -EFAULT. + * fault happens, handle that and return -EFAULT. If @src is not a valid kernel + * address, return -ERANGE. * * We ensure that the copy_from_user is executed in atomic context so that * do_page_fault() doesn't attempt to take mmap_lock. This makes @@ -106,7 +107,7 @@ long probe_kernel_read(void *dst, const mm_segment_t old_fs = get_fs(); if (!probe_kernel_read_allowed(src, size)) - return -EFAULT; + return -ERANGE; set_fs(KERNEL_DS); pagefault_disable(); @@ -158,8 +159,9 @@ long probe_kernel_write(void *dst, const * * On success, returns the length of the string INCLUDING the trailing NUL. * - * If access fails, returns -EFAULT (some data may have been copied - * and the trailing NUL added). + * If access fails, returns -EFAULT (some data may have been copied and the + * trailing NUL added). If @unsafe_addr is not a valid kernel address, return + * -ERANGE. * * If @count is smaller than the length of the string, copies @count-1 bytes, * sets the last byte of @dst buffer to NUL and returns @count. @@ -173,7 +175,7 @@ long strncpy_from_kernel_nofault(char *d if (unlikely(count <= 0)) return 0; if (!probe_kernel_read_allowed(unsafe_addr, count)) - return -EFAULT; + return -ERANGE; set_fs(KERNEL_DS); pagefault_disable(); _ Patches currently in -mm which might be from hch@lst.de are x86-hyperv-use-vmalloc_exec-for-the-hypercall-page.patch x86-fix-vmap-arguments-in-map_irq_stack.patch staging-android-ion-use-vmap-instead-of-vm_map_ram.patch staging-media-ipu3-use-vmap-instead-of-reimplementing-it.patch dma-mapping-use-vmap-insted-of-reimplementing-it.patch powerpc-add-an-ioremap_phb-helper.patch powerpc-remove-__ioremap_at-and-__iounmap_at.patch mm-remove-__get_vm_area.patch mm-unexport-unmap_kernel_range_noflush.patch mm-rename-config_pgtable_mapping-to-config_zsmalloc_pgtable_mapping.patch mm-only-allow-page-table-mappings-for-built-in-zsmalloc.patch mm-pass-addr-as-unsigned-long-to-vb_free.patch mm-remove-vmap_page_range_noflush-and-vunmap_page_range.patch mm-rename-vmap_page_range-to-map_kernel_range.patch mm-dont-return-the-number-of-pages-from-map_kernel_range_noflush.patch mm-remove-map_vm_range.patch mm-remove-unmap_vmap_area.patch mm-remove-the-prot-argument-from-vm_map_ram.patch mm-enforce-that-vmap-cant-map-pages-executable.patch gpu-drm-remove-the-powerpc-hack-in-drm_legacy_sg_alloc.patch mm-remove-the-pgprot-argument-to-__vmalloc.patch mm-remove-the-prot-argument-to-__vmalloc_node.patch mm-remove-both-instances-of-__vmalloc_node_flags.patch mm-remove-__vmalloc_node_flags_caller.patch mm-switch-the-test_vmalloc-module-to-use-__vmalloc_node.patch mm-remove-vmalloc_user_node_flags.patch arm64-use-__vmalloc_node-in-arch_alloc_vmap_stack.patch powerpc-use-__vmalloc_node-in-alloc_vm_stack.patch s390-use-__vmalloc_node-in-stack_alloc.patch exec-simplify-the-copy_strings_kernel-calling-convention.patch exec-open-code-copy_string_kernel.patch amdgpu-a-null-mm-does-not-mean-a-thread-is-a-kthread.patch kernel-move-use_mm-unuse_mm-to-kthreadc.patch kernel-move-use_mm-unuse_mm-to-kthreadc-v2.patch kernel-better-document-the-use_mm-unuse_mm-api-contract.patch kernel-better-document-the-use_mm-unuse_mm-api-contract-v2.patch kernel-set-user_ds-in-kthread_use_mm.patch arm-fix-the-flush_icache_range-arguments-in-set_fiq_handler.patch nds32-unexport-flush_icache_page.patch powerpc-unexport-flush_icache_user_range.patch unicore32-remove-flush_cache_user_range.patch asm-generic-fix-the-inclusion-guards-for-cacheflushh.patch asm-generic-dont-include-linux-mmh-in-cacheflushh.patch asm-generic-dont-include-linux-mmh-in-cacheflushh-fix.patch asm-generic-improve-the-flush_dcache_page-stub.patch alpha-use-asm-generic-cacheflushh.patch arm64-use-asm-generic-cacheflushh.patch c6x-use-asm-generic-cacheflushh.patch hexagon-use-asm-generic-cacheflushh.patch ia64-use-asm-generic-cacheflushh.patch microblaze-use-asm-generic-cacheflushh.patch m68knommu-use-asm-generic-cacheflushh.patch openrisc-use-asm-generic-cacheflushh.patch powerpc-use-asm-generic-cacheflushh.patch riscv-use-asm-generic-cacheflushh.patch armsparcunicore32-remove-flush_icache_user_range.patch mm-rename-flush_icache_user_range-to-flush_icache_user_page.patch asm-generic-add-a-flush_icache_user_range-stub.patch sh-implement-flush_icache_user_range.patch xtensa-implement-flush_icache_user_range.patch arm-rename-flush_cache_user_range-to-flush_icache_user_range.patch m68k-implement-flush_icache_user_range.patch exec-only-build-read_code-when-needed.patch exec-use-flush_icache_user_range-in-read_code.patch binfmt_flat-use-flush_icache_user_range.patch nommu-use-flush_icache_user_range-in-brk-and-mmap.patch module-move-the-set_fs-hack-for-flush_icache_range-to-m68k.patch maccess-unexport-probe_kernel_write-and-probe_user_write.patch maccess-remove-various-unused-weak-aliases.patch maccess-remove-duplicate-kerneldoc-comments.patch maccess-clarify-kerneldoc-comments.patch maccess-update-the-top-of-file-comment.patch maccess-rename-strncpy_from_unsafe_user-to-strncpy_from_user_nofault.patch maccess-rename-strncpy_from_unsafe_strict-to-strncpy_from_kernel_nofault.patch maccess-rename-strnlen_unsafe_user-to-strnlen_user_nofault.patch maccess-remove-probe_read_common-and-probe_write_common.patch maccess-unify-the-probe-kernel-arch-hooks.patch bpf-factor-out-a-bpf_trace_copy_string-helper.patch bpf-handle-the-compat-string-in-bpf_trace_copy_string-better.patch bpf-rework-the-compat-kernel-probe-handling.patch tracing-kprobes-handle-mixed-kernel-userspace-probes-better.patch maccess-remove-strncpy_from_unsafe.patch maccess-always-use-strict-semantics-for-probe_kernel_read.patch maccess-move-user-access-routines-together.patch maccess-allow-architectures-to-provide-kernel-probing-directly.patch x86-use-non-set_fs-based-maccess-routines.patch maccess-return-erange-when-copy_from_kernel_nofault_allowed-fails.patch