ELF: Add ELF program property parsing support (00e19cee) · Commits · 戴 / test

fs/binfmt_elf.c

+127 −0

Original line number	Diff line number	Diff line
		@@ -39,12 +39,18 @@
		#include <linux/sched/coredump.h>
		#include <linux/sched/task_stack.h>
		#include <linux/sched/cputime.h>
		#include <linux/sizes.h>
		#include <linux/types.h>
		#include <linux/cred.h>
		#include <linux/dax.h>
		#include <linux/uaccess.h>
		#include <asm/param.h>
		#include <asm/page.h>

		#ifndef ELF_COMPAT
		#define ELF_COMPAT 0
		#endif

		#ifndef user_long_t
		#define user_long_t long
		#endif
		@@ -681,6 +687,111 @@ out:
		* libraries. There is no binary dependent code anywhere else.
		*/

		static int parse_elf_property(const char data, size_t off, size_t datasz,
		struct arch_elf_state *arch,
		bool have_prev_type, u32 *prev_type)
		{
		size_t o, step;
		const struct gnu_property *pr;
		int ret;

		if (*off == datasz)
		return -ENOENT;

		if (WARN_ON_ONCE(off > datasz \|\| off % ELF_GNU_PROPERTY_ALIGN))
		return -EIO;
		o = *off;
		datasz -= *off;

		if (datasz < sizeof(*pr))
		return -ENOEXEC;
		pr = (const struct gnu_property *)(data + o);
		o += sizeof(*pr);
		datasz -= sizeof(*pr);

		if (pr->pr_datasz > datasz)
		return -ENOEXEC;

		WARN_ON_ONCE(o % ELF_GNU_PROPERTY_ALIGN);
		step = round_up(pr->pr_datasz, ELF_GNU_PROPERTY_ALIGN);
		if (step > datasz)
		return -ENOEXEC;

		/* Properties are supposed to be unique and sorted on pr_type: */
		if (have_prev_type && pr->pr_type <= *prev_type)
		return -ENOEXEC;
		*prev_type = pr->pr_type;

		ret = arch_parse_elf_property(pr->pr_type, data + o,
		pr->pr_datasz, ELF_COMPAT, arch);
		if (ret)
		return ret;

		*off = o + step;
		return 0;
		}

		#define NOTE_DATA_SZ SZ_1K
		#define GNU_PROPERTY_TYPE_0_NAME "GNU"
		#define NOTE_NAME_SZ (sizeof(GNU_PROPERTY_TYPE_0_NAME))

		static int parse_elf_properties(struct file f, const struct elf_phdr phdr,
		struct arch_elf_state *arch)
		{
		union {
		struct elf_note nhdr;
		char data[NOTE_DATA_SZ];
		} note;
		loff_t pos;
		ssize_t n;
		size_t off, datasz;
		int ret;
		bool have_prev_type;
		u32 prev_type;

		if (!IS_ENABLED(CONFIG_ARCH_USE_GNU_PROPERTY) \|\| !phdr)
		return 0;

		/* load_elf_binary() shouldn't call us unless this is true... */
		if (WARN_ON_ONCE(phdr->p_type != PT_GNU_PROPERTY))
		return -ENOEXEC;

		/* If the properties are crazy large, that's too bad (for now): */
		if (phdr->p_filesz > sizeof(note))
		return -ENOEXEC;

		pos = phdr->p_offset;
		n = kernel_read(f, &note, phdr->p_filesz, &pos);

		BUILD_BUG_ON(sizeof(note) < sizeof(note.nhdr) + NOTE_NAME_SZ);
		if (n < 0 \|\| n < sizeof(note.nhdr) + NOTE_NAME_SZ)
		return -EIO;

		if (note.nhdr.n_type != NT_GNU_PROPERTY_TYPE_0 \|\|
		note.nhdr.n_namesz != NOTE_NAME_SZ \|\|
		strncmp(note.data + sizeof(note.nhdr),
		GNU_PROPERTY_TYPE_0_NAME, n - sizeof(note.nhdr)))
		return -ENOEXEC;

		off = round_up(sizeof(note.nhdr) + NOTE_NAME_SZ,
		ELF_GNU_PROPERTY_ALIGN);
		if (off > n)
		return -ENOEXEC;

		if (note.nhdr.n_descsz > n - off)
		return -ENOEXEC;
		datasz = off + note.nhdr.n_descsz;

		have_prev_type = false;
		do {
		ret = parse_elf_property(note.data, &off, datasz, arch,
		have_prev_type, &prev_type);
		have_prev_type = true;
		} while (!ret);

		return ret == -ENOENT ? 0 : ret;
		}

		static int load_elf_binary(struct linux_binprm *bprm)
		{
		struct file interpreter = NULL; / to shut gcc up */
		@@ -688,6 +799,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
		int load_addr_set = 0;
		unsigned long error;
		struct elf_phdr elf_ppnt, elf_phdata, *interp_elf_phdata = NULL;
		struct elf_phdr *elf_property_phdata = NULL;
		unsigned long elf_bss, elf_brk;
		int bss_prot = 0;
		int retval, i;
		@@ -733,6 +845,11 @@ static int load_elf_binary(struct linux_binprm *bprm)
		for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++) {
		char *elf_interpreter;

		if (elf_ppnt->p_type == PT_GNU_PROPERTY) {
		elf_property_phdata = elf_ppnt;
		continue;
		}

		if (elf_ppnt->p_type != PT_INTERP)
		continue;

		@@ -820,9 +937,14 @@ out_free_interp:
		goto out_free_dentry;

		/* Pass PT_LOPROC..PT_HIPROC headers to arch code */
		elf_property_phdata = NULL;
		elf_ppnt = interp_elf_phdata;
		for (i = 0; i < loc->interp_elf_ex.e_phnum; i++, elf_ppnt++)
		switch (elf_ppnt->p_type) {
		case PT_GNU_PROPERTY:
		elf_property_phdata = elf_ppnt;
		break;

		case PT_LOPROC ... PT_HIPROC:
		retval = arch_elf_pt_proc(&loc->interp_elf_ex,
		elf_ppnt, interpreter,
		@@ -833,6 +955,11 @@ out_free_interp:
		}
		}

		retval = parse_elf_properties(interpreter ?: bprm->file,
		elf_property_phdata, &arch_state);
		if (retval)
		goto out_free_dentry;

		/*
		* Allow arch code to reject the ELF at this point, whilst it's
		* still possible to return an error to the code that invoked

fs/compat_binfmt_elf.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -17,6 +17,8 @@
		#include <linux/elfcore-compat.h>
		#include <linux/time.h>

		#define ELF_COMPAT 1

		/*
		* Rename the basic ELF layout types to refer to the 32-bit class of files.
		*/
		@@ -28,11 +30,13 @@
		#undef elf_shdr
		#undef elf_note
		#undef elf_addr_t
		#undef ELF_GNU_PROPERTY_ALIGN
		#define elfhdr elf32_hdr
		#define elf_phdr elf32_phdr
		#define elf_shdr elf32_shdr
		#define elf_note elf32_note
		#define elf_addr_t Elf32_Addr
		#define ELF_GNU_PROPERTY_ALIGN ELF32_GNU_PROPERTY_ALIGN

		/*
		* Some data types as stored in coredump.

include/linux/elf.h

+19 −0

Original line number	Diff line number	Diff line
		@@ -22,6 +22,9 @@
		SET_PERSONALITY(ex)
		#endif

		#define ELF32_GNU_PROPERTY_ALIGN 4
		#define ELF64_GNU_PROPERTY_ALIGN 8

		#if ELF_CLASS == ELFCLASS32

		extern Elf32_Dyn _DYNAMIC [];
		@@ -32,6 +35,7 @@ extern Elf32_Dyn _DYNAMIC [];
		#define elf_addr_t Elf32_Off
		#define Elf_Half Elf32_Half
		#define Elf_Word Elf32_Word
		#define ELF_GNU_PROPERTY_ALIGN ELF32_GNU_PROPERTY_ALIGN

		#else

		@@ -43,6 +47,7 @@ extern Elf64_Dyn _DYNAMIC [];
		#define elf_addr_t Elf64_Off
		#define Elf_Half Elf64_Half
		#define Elf_Word Elf64_Word
		#define ELF_GNU_PROPERTY_ALIGN ELF64_GNU_PROPERTY_ALIGN

		#endif

		@@ -68,4 +73,18 @@ struct gnu_property {
		u32 pr_datasz;
		};

		struct arch_elf_state;

		#ifndef CONFIG_ARCH_USE_GNU_PROPERTY
		static inline int arch_parse_elf_property(u32 type, const void *data,
		size_t datasz, bool compat,
		struct arch_elf_state *arch)
		{
		return 0;
		}
		#else
		extern int arch_parse_elf_property(u32 type, const void *data, size_t datasz,
		bool compat, struct arch_elf_state *arch);
		#endif

		#endif /* _LINUX_ELF_H */

include/uapi/linux/elf.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -368,6 +368,7 @@ typedef struct elf64_shdr {
		* Notes used in ET_CORE. Architectures export some of the arch register sets
		* using the corresponding note types via the PTRACE_GETREGSET and
		* PTRACE_SETREGSET requests.
		* The note name for all these is "LINUX".
		*/
		#define NT_PRSTATUS 1
		#define NT_PRFPREG 2
		@@ -430,6 +431,9 @@ typedef struct elf64_shdr {
		#define NT_MIPS_FP_MODE 0x801 /* MIPS floating-point mode */
		#define NT_MIPS_MSA 0x802 /* MIPS SIMD registers */

		/* Note types with note name "GNU" */
		#define NT_GNU_PROPERTY_TYPE_0 5

		/* Note header in a PT_NOTE section */
		typedef struct elf32_note {
		Elf32_Word n_namesz; /* Name size */

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