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	 0fa8e08464
			
		
	
	
		0fa8e08464
		
	
	
	
	
		
			
			To perform partial reads, callers of kernel_read_file*() must have a non-NULL file_size argument and a preallocated buffer. The new "offset" argument can then be used to seek to specific locations in the file to fill the buffer to, at most, "buf_size" per call. Where possible, the LSM hooks can report whether a full file has been read or not so that the contents can be reasoned about. Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201002173828.2099543-14-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
		
			
				
	
	
		
			55 lines
		
	
	
	
		
			1.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			55 lines
		
	
	
	
		
			1.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| #ifndef _LINUX_KERNEL_READ_FILE_H
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| #define _LINUX_KERNEL_READ_FILE_H
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| 
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| #include <linux/file.h>
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| #include <linux/types.h>
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| 
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| /* This is a list of *what* is being read, not *how* nor *where*. */
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| #define __kernel_read_file_id(id) \
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| 	id(UNKNOWN, unknown)		\
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| 	id(FIRMWARE, firmware)		\
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| 	id(MODULE, kernel-module)		\
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| 	id(KEXEC_IMAGE, kexec-image)		\
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| 	id(KEXEC_INITRAMFS, kexec-initramfs)	\
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| 	id(POLICY, security-policy)		\
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| 	id(X509_CERTIFICATE, x509-certificate)	\
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| 	id(MAX_ID, )
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| 
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| #define __fid_enumify(ENUM, dummy) READING_ ## ENUM,
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| #define __fid_stringify(dummy, str) #str,
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| 
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| enum kernel_read_file_id {
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| 	__kernel_read_file_id(__fid_enumify)
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| };
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| 
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| static const char * const kernel_read_file_str[] = {
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| 	__kernel_read_file_id(__fid_stringify)
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| };
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| 
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| static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
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| {
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| 	if ((unsigned int)id >= READING_MAX_ID)
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| 		return kernel_read_file_str[READING_UNKNOWN];
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| 
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| 	return kernel_read_file_str[id];
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| }
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| 
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| int kernel_read_file(struct file *file, loff_t offset,
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| 		     void **buf, size_t buf_size,
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| 		     size_t *file_size,
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| 		     enum kernel_read_file_id id);
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| int kernel_read_file_from_path(const char *path, loff_t offset,
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| 			       void **buf, size_t buf_size,
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| 			       size_t *file_size,
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| 			       enum kernel_read_file_id id);
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| int kernel_read_file_from_path_initns(const char *path, loff_t offset,
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| 				      void **buf, size_t buf_size,
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| 				      size_t *file_size,
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| 				      enum kernel_read_file_id id);
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| int kernel_read_file_from_fd(int fd, loff_t offset,
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| 			     void **buf, size_t buf_size,
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| 			     size_t *file_size,
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| 			     enum kernel_read_file_id id);
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| 
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| #endif /* _LINUX_KERNEL_READ_FILE_H */
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