46 lines
1.2 KiB
C
46 lines
1.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/uaccess.h>
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#include <linux/kernel.h>
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#include <asm/vsyscall.h>
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#ifdef CONFIG_X86_64
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static __always_inline bool invalid_probe_range(u64 vaddr)
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{
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/*
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* Range covering the highest possible canonical userspace address
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* as well as non-canonical address range. For the canonical range
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* we also need to include the userspace guard page.
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*
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* Reading from the vsyscall page may cause an unhandled fault in
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* certain cases. Though it is at an address above TASK_SIZE_MAX,
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* it is usually considered as a user space address.
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*/
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return vaddr < TASK_SIZE_MAX + PAGE_SIZE ||
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!__is_canonical_address(vaddr, boot_cpu_data.x86_virt_bits) ||
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is_vsyscall_vaddr(vaddr);
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}
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#else
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static __always_inline bool invalid_probe_range(u64 vaddr)
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{
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return vaddr < TASK_SIZE_MAX;
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}
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#endif
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long probe_kernel_read_strict(void *dst, const void *src, size_t size)
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{
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if (unlikely(invalid_probe_range((unsigned long)src)))
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return -EFAULT;
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return __probe_kernel_read(dst, src, size);
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}
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long strncpy_from_unsafe_strict(char *dst, const void *unsafe_addr, long count)
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{
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if (unlikely(invalid_probe_range((unsigned long)unsafe_addr)))
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return -EFAULT;
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return __strncpy_from_unsafe(dst, unsafe_addr, count);
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}
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