Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 426 insertions, 0 deletions

diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c
new file mode 100644
index 000000000..c3deb2e35
--- /dev/null
+++ b/fs/binfmt_aout.c
@@ -0,0 +1,426 @@
+/*
+ *  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>
+#include <asm/a.out-core.h>
+
+static int load_aout_binary(struct linux_binprm *);
+static int load_aout_library(struct file*);
+
+#ifdef CONFIG_COREDUMP
+/*
+ * Routine writes a core dump image in the current directory.
+ * Currently only a stub-function.
+ *
+ * Note that setuid/setgid files won't make a core-dump if the uid/gid
+ * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
+ * field, which also makes sure the core-dumps won't be recursive if the
+ * dumping of the process results in another error..
+ */
+static int aout_core_dump(struct coredump_params *cprm)
+{
+	mm_segment_t fs;
+	int has_dumped = 0;
+	void __user *dump_start;
+	int dump_size;
+	struct user dump;
+#ifdef __alpha__
+#       define START_DATA(u)	((void __user *)u.start_data)
+#else
+#	define START_DATA(u)	((void __user *)((u.u_tsize << PAGE_SHIFT) + \
+				 u.start_code))
+#endif
+#       define START_STACK(u)   ((void __user *)u.start_stack)
+
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+	has_dumped = 1;
+       	strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
+	dump.u_ar0 = offsetof(struct user, regs);
+	dump.signal = cprm->siginfo->si_signo;
+	aout_dump_thread(cprm->regs, &dump);
+
+/* If the size of the dump file exceeds the rlimit, then see what would happen
+   if we wrote the stack, but not the data area.  */
+	if ((dump.u_dsize + dump.u_ssize+1) * PAGE_SIZE > cprm->limit)
+		dump.u_dsize = 0;
+
+/* Make sure we have enough room to write the stack and data areas. */
+	if ((dump.u_ssize + 1) * PAGE_SIZE > cprm->limit)
+		dump.u_ssize = 0;
+
+/* make sure we actually have a data and stack area to dump */
+	set_fs(USER_DS);
+	if (!access_ok(VERIFY_READ, START_DATA(dump), dump.u_dsize << PAGE_SHIFT))
+		dump.u_dsize = 0;
+	if (!access_ok(VERIFY_READ, START_STACK(dump), dump.u_ssize << PAGE_SHIFT))
+		dump.u_ssize = 0;
+
+	set_fs(KERNEL_DS);
+/* struct user */
+	if (!dump_emit(cprm, &dump, sizeof(dump)))
+		goto end_coredump;
+/* Now dump all of the user data.  Include malloced stuff as well */
+	if (!dump_skip(cprm, PAGE_SIZE - sizeof(dump)))
+		goto end_coredump;
+/* now we start writing out the user space info */
+	set_fs(USER_DS);
+/* Dump the data area */
+	if (dump.u_dsize != 0) {
+		dump_start = START_DATA(dump);
+		dump_size = dump.u_dsize << PAGE_SHIFT;
+		if (!dump_emit(cprm, dump_start, dump_size))
+			goto end_coredump;
+	}
+/* Now prepare to dump the stack area */
+	if (dump.u_ssize != 0) {
+		dump_start = START_STACK(dump);
+		dump_size = dump.u_ssize << PAGE_SHIFT;
+		if (!dump_emit(cprm, dump_start, dump_size))
+			goto end_coredump;
+	}
+end_coredump:
+	set_fs(fs);
+	return has_dumped;
+}
+#else
+#define aout_core_dump NULL
+#endif
+
+static struct linux_binfmt aout_format = {
+	.module		= THIS_MODULE,
+	.load_binary	= load_aout_binary,
+	.load_shlib	= load_aout_library,
+	.core_dump	= aout_core_dump,
+	.min_coredump	= PAGE_SIZE
+};
+
+#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 = flush_old_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;
+
+	install_exec_creds(bprm);
+
+	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 | MAP_DENYWRITE | MAP_EXECUTABLE,
+			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 | MAP_DENYWRITE | MAP_EXECUTABLE,
+				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 | MAP_DENYWRITE,
+			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");