Commit 987f20a9 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Kees Cook

a.out: Remove the a.out implementation

In commit 19e8b701 ("a.out: Stop building a.out/osf1 support on
alpha and m68k") the last users of a.out were disabled.

As nothing has turned up to cause this change to be reverted, let's
remove the code implementing a.out support as well.

There may be userspace users of the uapi bits left so the uapi
headers have been left untouched.
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Arnd Bergmann <arnd@arndb.de> # arm defconfigs
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/871qrx3hq3.fsf@email.froward.int.ebiederm.org
parent 33a2d6bc
......@@ -7685,7 +7685,6 @@ R: Kees Cook <keescook@chromium.org>
L: linux-mm@kvack.org
S: Supported
T: git git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git for-next/execve
F: arch/alpha/kernel/binfmt_loader.c
F: fs/*binfmt_*.c
F: fs/exec.c
F: include/linux/binfmts.h
......
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ALPHA_A_OUT_H__
#define __ALPHA_A_OUT_H__
#include <uapi/asm/a.out.h>
/* Assume that start addresses below 4G belong to a TASO application.
Unfortunately, there is no proper bit in the exec header to check.
Worse, we have to notice the start address before swapping to use
/sbin/loader, which of course is _not_ a TASO application. */
#define SET_AOUT_PERSONALITY(BFPM, EX) \
set_personality (((BFPM->taso || EX.ah.entry < 0x100000000L \
? ADDR_LIMIT_32BIT : 0) | PER_OSF4))
#endif /* __A_OUT_GNU_H__ */
......@@ -47,10 +47,6 @@ else
# Misc support
obj-$(CONFIG_ALPHA_SRM) += srmcons.o
ifdef CONFIG_BINFMT_AOUT
obj-y += binfmt_loader.o
endif
# Core logic support
obj-$(CONFIG_ALPHA_APECS) += core_apecs.o
obj-$(CONFIG_ALPHA_CIA) += core_cia.o
......
// SPDX-License-Identifier: GPL-2.0
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mm_types.h>
#include <linux/binfmts.h>
#include <linux/a.out.h>
static int load_binary(struct linux_binprm *bprm)
{
struct exec *eh = (struct exec *)bprm->buf;
unsigned long loader;
struct file *file;
int retval;
if (eh->fh.f_magic != 0x183 || (eh->fh.f_flags & 0x3000) != 0x3000)
return -ENOEXEC;
if (bprm->loader)
return -ENOEXEC;
loader = bprm->vma->vm_end - sizeof(void *);
file = open_exec("/sbin/loader");
retval = PTR_ERR(file);
if (IS_ERR(file))
return retval;
/* Remember if the application is TASO. */
bprm->taso = eh->ah.entry < 0x100000000UL;
bprm->interpreter = file;
bprm->loader = loader;
return 0;
}
static struct linux_binfmt loader_format = {
.load_binary = load_binary,
};
static int __init init_loader_binfmt(void)
{
insert_binfmt(&loader_format);
return 0;
}
arch_initcall(init_loader_binfmt);
......@@ -1278,45 +1278,15 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
return addr;
}
#ifdef CONFIG_OSF4_COMPAT
/* Clear top 32 bits of iov_len in the user's buffer for
compatibility with old versions of OSF/1 where iov_len
was defined as int. */
static int
osf_fix_iov_len(const struct iovec __user *iov, unsigned long count)
{
unsigned long i;
for (i = 0 ; i < count ; i++) {
int __user *iov_len_high = (int __user *)&iov[i].iov_len + 1;
if (put_user(0, iov_len_high))
return -EFAULT;
}
return 0;
}
#endif
SYSCALL_DEFINE3(osf_readv, unsigned long, fd,
const struct iovec __user *, vector, unsigned long, count)
{
#ifdef CONFIG_OSF4_COMPAT
if (unlikely(personality(current->personality) == PER_OSF4))
if (osf_fix_iov_len(vector, count))
return -EFAULT;
#endif
return sys_readv(fd, vector, count);
}
SYSCALL_DEFINE3(osf_writev, unsigned long, fd,
const struct iovec __user *, vector, unsigned long, count)
{
#ifdef CONFIG_OSF4_COMPAT
if (unlikely(personality(current->personality) == PER_OSF4))
if (osf_fix_iov_len(vector, count))
return -EFAULT;
#endif
return sys_writev(fd, vector, count);
}
......
......@@ -6,7 +6,6 @@ CONFIG_UNUSED_BOARD_FILES=y
CONFIG_CMDLINE="init=/linuxrc root=/dev/mtdblock3"
CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
CONFIG_FPE_NWFPE=y
CONFIG_BINFMT_AOUT=m
CONFIG_MODULES=y
CONFIG_MODVERSIONS=y
CONFIG_PARTITION_ADVANCED=y
......
......@@ -16,7 +16,6 @@ CONFIG_MACH_HUSKY=y
CONFIG_UNUSED_BOARD_FILES=y
CONFIG_CMDLINE="console=ttyS0,115200n8 console=tty1 noinitrd root=/dev/mtdblock2 rootfstype=jffs2 debug"
CONFIG_FPE_NWFPE=y
CONFIG_BINFMT_AOUT=m
CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
CONFIG_MODULE_FORCE_UNLOAD=y
......
......@@ -25,7 +25,6 @@ CONFIG_CPU_FREQ_GOV_ONDEMAND=m
CONFIG_CPU_FREQ_GOV_CONSERVATIVE=m
CONFIG_CPU_IDLE=y
CONFIG_FPE_NWFPE=y
CONFIG_BINFMT_AOUT=m
CONFIG_PM=y
CONFIG_APM_EMULATION=y
CONFIG_MODULES=y
......
......@@ -9,7 +9,6 @@ CONFIG_ARCH_EBSA285_HOST=y
CONFIG_ARCH_NETWINDER=y
CONFIG_FPE_NWFPE=y
CONFIG_FPE_NWFPE_XP=y
CONFIG_BINFMT_AOUT=y
CONFIG_MODULES=y
CONFIG_PARTITION_ADVANCED=y
CONFIG_ACORN_PARTITION=y
......
......@@ -7,7 +7,6 @@ CONFIG_UNUSED_BOARD_FILES=y
CONFIG_CMDLINE="console=ttySA0,115200 root=/dev/ram0 initrd=0xc0400000,8M init=/rootshell"
CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
CONFIG_FPE_NWFPE=y
CONFIG_BINFMT_AOUT=y
CONFIG_MODULES=y
CONFIG_NET=y
CONFIG_PACKET=y
......
......@@ -12,7 +12,6 @@ CONFIG_MACH_N2100=y
CONFIG_UNUSED_BOARD_FILES=y
CONFIG_CMDLINE="console=ttyS0,115200 root=/dev/nfs ip=bootp cachepolicy=writealloc"
CONFIG_FPE_NWFPE=y
CONFIG_BINFMT_AOUT=y
CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
CONFIG_PARTITION_ADVANCED=y
......
......@@ -6,7 +6,6 @@ CONFIG_SA1100_JORNADA720=y
CONFIG_SA1100_JORNADA720_SSP=y
CONFIG_UNUSED_BOARD_FILES=y
CONFIG_FPE_NWFPE=y
CONFIG_BINFMT_AOUT=y
CONFIG_PM=y
CONFIG_MODULES=y
CONFIG_NET=y
......
......@@ -8,7 +8,6 @@ CONFIG_CMDLINE="console=ttySA0,9600 root=/dev/ram"
CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y
CONFIG_CPU_FREQ_GOV_USERSPACE=y
CONFIG_FPE_NWFPE=y
CONFIG_BINFMT_AOUT=y
CONFIG_PM=y
CONFIG_MODULES=y
CONFIG_NET=y
......
......@@ -9,7 +9,6 @@ CONFIG_ZBOOT_ROM_BSS=0xc1000000
CONFIG_ZBOOT_ROM=y
CONFIG_CMDLINE="console=ttySA0,38400n8 cpufreq=221200 rw root=/dev/mtdblock2 mtdparts=sa1100:512K(boot),1M(kernel),2560K(initrd),4M(root) load_ramdisk=1 prompt_ramdisk=0 mem=32M noinitrd initrd=0xc0800000,3M"
CONFIG_FPE_NWFPE=y
CONFIG_BINFMT_AOUT=y
CONFIG_PM=y
CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
......
......@@ -5,7 +5,6 @@ CONFIG_ARCH_NETWINDER=y
CONFIG_DEPRECATED_PARAM_STRUCT=y
CONFIG_CMDLINE="root=0x801"
CONFIG_FPE_NWFPE=y
CONFIG_BINFMT_AOUT=y
CONFIG_PARTITION_ADVANCED=y
CONFIG_NET=y
CONFIG_PACKET=y
......
......@@ -7,7 +7,6 @@ CONFIG_MODULE_UNLOAD=y
CONFIG_ARCH_RPC=y
CONFIG_CPU_SA110=y
CONFIG_FPE_NWFPE=y
CONFIG_BINFMT_AOUT=y
CONFIG_PARTITION_ADVANCED=y
CONFIG_BSD_DISKLABEL=y
CONFIG_SLAB=y
......
......@@ -13,7 +13,6 @@ CONFIG_MACH_AKITA=y
CONFIG_MACH_BORZOI=y
CONFIG_CMDLINE="console=ttyS0,115200n8 console=tty1 noinitrd root=/dev/mtdblock2 rootfstype=jffs2 debug"
CONFIG_FPE_NWFPE=y
CONFIG_BINFMT_AOUT=m
CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
CONFIG_MODULE_FORCE_UNLOAD=y
......
......@@ -142,39 +142,6 @@ config BINFMT_ZFLAT
help
Support FLAT format compressed binaries
config HAVE_AOUT
def_bool n
config BINFMT_AOUT
tristate "Kernel support for a.out and ECOFF binaries"
depends on HAVE_AOUT
help
A.out (Assembler.OUTput) is a set of formats for libraries and
executables used in the earliest versions of UNIX. Linux used
the a.out formats QMAGIC and ZMAGIC until they were replaced
with the ELF format.
The conversion to ELF started in 1995. This option is primarily
provided for historical interest and for the benefit of those
who need to run binaries from that era.
Most people should answer N here. If you think you may have
occasional use for this format, enable module support above
and answer M here to compile this support as a module called
binfmt_aout.
If any crucial components of your system (such as /sbin/init
or /lib/ld.so) are still in a.out format, you will have to
say Y here.
config OSF4_COMPAT
bool "OSF/1 v4 readv/writev compatibility"
depends on ALPHA && BINFMT_AOUT
help
Say Y if you are using OSF/1 binaries (like Netscape and Acrobat)
with v4 shared libraries freely available from Compaq. If you're
going to use shared libraries from Tru64 version 5.0 or later, say N.
config BINFMT_MISC
tristate "Kernel support for MISC binaries"
help
......
......@@ -38,7 +38,6 @@ obj-$(CONFIG_FS_DAX) += dax.o
obj-$(CONFIG_FS_ENCRYPTION) += crypto/
obj-$(CONFIG_FS_VERITY) += verity/
obj-$(CONFIG_FILE_LOCKING) += locks.o
obj-$(CONFIG_BINFMT_AOUT) += binfmt_aout.o
obj-$(CONFIG_BINFMT_MISC) += binfmt_misc.o
obj-$(CONFIG_BINFMT_SCRIPT) += binfmt_script.o
obj-$(CONFIG_BINFMT_ELF) += binfmt_elf.o
......
// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/fs/binfmt_aout.c
*
* Copyright (C) 1991, 1992, 1996 Linus Torvalds
*/
#include <linux/module.h>
#include <linux/time.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/a.out.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/binfmts.h>
#include <linux/personality.h>
#include <linux/init.h>
#include <linux/coredump.h>
#include <linux/slab.h>
#include <linux/sched/task_stack.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
static int load_aout_binary(struct linux_binprm *);
static int load_aout_library(struct file*);
static struct linux_binfmt aout_format = {
.module = THIS_MODULE,
.load_binary = load_aout_binary,
.load_shlib = load_aout_library,
};
#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
static int set_brk(unsigned long start, unsigned long end)
{
start = PAGE_ALIGN(start);
end = PAGE_ALIGN(end);
if (end > start)
return vm_brk(start, end - start);
return 0;
}
/*
* create_aout_tables() parses the env- and arg-strings in new user
* memory and creates the pointer tables from them, and puts their
* addresses on the "stack", returning the new stack pointer value.
*/
static unsigned long __user *create_aout_tables(char __user *p, struct linux_binprm * bprm)
{
char __user * __user *argv;
char __user * __user *envp;
unsigned long __user *sp;
int argc = bprm->argc;
int envc = bprm->envc;
sp = (void __user *)((-(unsigned long)sizeof(char *)) & (unsigned long) p);
#ifdef __alpha__
/* whee.. test-programs are so much fun. */
put_user(0, --sp);
put_user(0, --sp);
if (bprm->loader) {
put_user(0, --sp);
put_user(1003, --sp);
put_user(bprm->loader, --sp);
put_user(1002, --sp);
}
put_user(bprm->exec, --sp);
put_user(1001, --sp);
#endif
sp -= envc+1;
envp = (char __user * __user *) sp;
sp -= argc+1;
argv = (char __user * __user *) sp;
#ifndef __alpha__
put_user((unsigned long) envp,--sp);
put_user((unsigned long) argv,--sp);
#endif
put_user(argc,--sp);
current->mm->arg_start = (unsigned long) p;
while (argc-->0) {
char c;
put_user(p,argv++);
do {
get_user(c,p++);
} while (c);
}
put_user(NULL,argv);
current->mm->arg_end = current->mm->env_start = (unsigned long) p;
while (envc-->0) {
char c;
put_user(p,envp++);
do {
get_user(c,p++);
} while (c);
}
put_user(NULL,envp);
current->mm->env_end = (unsigned long) p;
return sp;
}
/*
* These are the functions used to load a.out style executables and shared
* libraries. There is no binary dependent code anywhere else.
*/
static int load_aout_binary(struct linux_binprm * bprm)
{
struct pt_regs *regs = current_pt_regs();
struct exec ex;
unsigned long error;
unsigned long fd_offset;
unsigned long rlim;
int retval;
ex = *((struct exec *) bprm->buf); /* exec-header */
if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
N_TRSIZE(ex) || N_DRSIZE(ex) ||
i_size_read(file_inode(bprm->file)) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
return -ENOEXEC;
}
/*
* Requires a mmap handler. This prevents people from using a.out
* as part of an exploit attack against /proc-related vulnerabilities.
*/
if (!bprm->file->f_op->mmap)
return -ENOEXEC;
fd_offset = N_TXTOFF(ex);
/* Check initial limits. This avoids letting people circumvent
* size limits imposed on them by creating programs with large
* arrays in the data or bss.
*/
rlim = rlimit(RLIMIT_DATA);
if (rlim >= RLIM_INFINITY)
rlim = ~0;
if (ex.a_data + ex.a_bss > rlim)
return -ENOMEM;
/* Flush all traces of the currently running executable */
retval = begin_new_exec(bprm);
if (retval)
return retval;
/* OK, This is the point of no return */
#ifdef __alpha__
SET_AOUT_PERSONALITY(bprm, ex);
#else
set_personality(PER_LINUX);
#endif
setup_new_exec(bprm);
current->mm->end_code = ex.a_text +
(current->mm->start_code = N_TXTADDR(ex));
current->mm->end_data = ex.a_data +
(current->mm->start_data = N_DATADDR(ex));
current->mm->brk = ex.a_bss +
(current->mm->start_brk = N_BSSADDR(ex));
retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
if (retval < 0)
return retval;
if (N_MAGIC(ex) == OMAGIC) {
unsigned long text_addr, map_size;
loff_t pos;
text_addr = N_TXTADDR(ex);
#ifdef __alpha__
pos = fd_offset;
map_size = ex.a_text+ex.a_data + PAGE_SIZE - 1;
#else
pos = 32;
map_size = ex.a_text+ex.a_data;
#endif
error = vm_brk(text_addr & PAGE_MASK, map_size);
if (error)
return error;
error = read_code(bprm->file, text_addr, pos,
ex.a_text+ex.a_data);
if ((signed long)error < 0)
return error;
} else {
if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
(N_MAGIC(ex) != NMAGIC) && printk_ratelimit())
{
printk(KERN_NOTICE "executable not page aligned\n");
}
if ((fd_offset & ~PAGE_MASK) != 0 && printk_ratelimit())
{
printk(KERN_WARNING
"fd_offset is not page aligned. Please convert program: %pD\n",
bprm->file);
}
if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
error = vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
if (error)
return error;
read_code(bprm->file, N_TXTADDR(ex), fd_offset,
ex.a_text + ex.a_data);
goto beyond_if;
}
error = vm_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
PROT_READ | PROT_EXEC, MAP_FIXED | MAP_PRIVATE,
fd_offset);
if (error != N_TXTADDR(ex))
return error;
error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE,
fd_offset + ex.a_text);
if (error != N_DATADDR(ex))
return error;
}
beyond_if:
set_binfmt(&aout_format);
retval = set_brk(current->mm->start_brk, current->mm->brk);
if (retval < 0)
return retval;
current->mm->start_stack =
(unsigned long) create_aout_tables((char __user *) bprm->p, bprm);
#ifdef __alpha__
regs->gp = ex.a_gpvalue;
#endif
finalize_exec(bprm);
start_thread(regs, ex.a_entry, current->mm->start_stack);
return 0;
}
static int load_aout_library(struct file *file)
{
struct inode * inode;
unsigned long bss, start_addr, len;
unsigned long error;
int retval;
struct exec ex;
loff_t pos = 0;
inode = file_inode(file);
retval = -ENOEXEC;
error = kernel_read(file, &ex, sizeof(ex), &pos);
if (error != sizeof(ex))
goto out;
/* We come in here for the regular a.out style of shared libraries */
if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
goto out;
}
/*
* Requires a mmap handler. This prevents people from using a.out
* as part of an exploit attack against /proc-related vulnerabilities.
*/
if (!file->f_op->mmap)
goto out;
if (N_FLAGS(ex))
goto out;
/* For QMAGIC, the starting address is 0x20 into the page. We mask
this off to get the starting address for the page */
start_addr = ex.a_entry & 0xfffff000;
if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
if (printk_ratelimit())
{
printk(KERN_WARNING
"N_TXTOFF is not page aligned. Please convert library: %pD\n",
file);
}
retval = vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
if (retval)
goto out;
read_code(file, start_addr, N_TXTOFF(ex),
ex.a_text + ex.a_data);
retval = 0;
goto out;
}
/* Now use mmap to map the library into memory. */
error = vm_mmap(file, start_addr, ex.a_text + ex.a_data,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE,
N_TXTOFF(ex));
retval = error;
if (error != start_addr)
goto out;
len = PAGE_ALIGN(ex.a_text + ex.a_data);
bss = ex.a_text + ex.a_data + ex.a_bss;
if (bss > len) {
retval = vm_brk(start_addr + len, bss - len);
if (retval)
goto out;
}
retval = 0;
out:
return retval;
}
static int __init init_aout_binfmt(void)
{
register_binfmt(&aout_format);
return 0;
}
static void __exit exit_aout_binfmt(void)
{
unregister_binfmt(&aout_format);
}
core_initcall(init_aout_binfmt);
module_exit(exit_aout_binfmt);
MODULE_LICENSE("GPL");
......@@ -957,8 +957,7 @@ struct file *open_exec(const char *name)
}
EXPORT_SYMBOL(open_exec);
#if defined(CONFIG_HAVE_AOUT) || defined(CONFIG_BINFMT_FLAT) || \
defined(CONFIG_BINFMT_ELF_FDPIC)
#if defined(CONFIG_BINFMT_FLAT) || defined(CONFIG_BINFMT_ELF_FDPIC)
ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len)
{
ssize_t res = vfs_read(file, (void __user *)addr, len, &pos);
......
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __A_OUT_GNU_H__
#define __A_OUT_GNU_H__
#include <uapi/linux/a.out.h>
#ifndef __ASSEMBLY__
#ifdef linux
#include <asm/page.h>
#if defined(__i386__) || defined(__mc68000__)
#else
#ifndef SEGMENT_SIZE
#define SEGMENT_SIZE PAGE_SIZE
#endif
#endif
#endif
#endif /*__ASSEMBLY__ */
#endif /* __A_OUT_GNU_H__ */
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