no MAX_ARG_PAGES -v2

Index: linux-2.6-2/include/asm-alpha/a.out.h
===================================================================
@@ -101,6 +101,8 @@ struct exec
 #define STACK_TOP \
   (current->personality & ADDR_LIMIT_32BIT ? 0x80000000 : 0x00120000000UL)
 
+#define STACK_TOP_MAX	0x00120000000UL
+
 #endif
 
 #endif /* __A_OUT_GNU_H__ */

Index: linux-2.6-2/include/asm-arm/a.out.h
===================================================================
@@ -30,6 +30,7 @@ struct exec
 #ifdef __KERNEL__
 #define STACK_TOP	((current->personality == PER_LINUX_32BIT) ? \
 			 TASK_SIZE : TASK_SIZE_26)
+#define STACK_TOP_MAX	TASK_SIZE
 #endif
 
 #ifndef LIBRARY_START_TEXT

Index: linux-2.6-2/include/asm-arm26/a.out.h
===================================================================
@@ -29,6 +29,7 @@ struct exec
 
 #ifdef __KERNEL__
 #define STACK_TOP	TASK_SIZE
+#define STACK_TOP_MAX	STACK_TOP
 #endif
 
 #ifndef LIBRARY_START_TEXT

Index: linux-2.6-2/include/asm-avr32/a.out.h
===================================================================
@@ -20,6 +20,7 @@ struct exec
 #ifdef __KERNEL__
 
 #define STACK_TOP	TASK_SIZE
+#define STACK_TOP_MAX	STACK_TOP
 
 #endif
 

Index: linux-2.6-2/include/asm-cris/a.out.h
===================================================================
@@ -8,6 +8,7 @@
 
 /* grabbed from the intel stuff  */   
 #define STACK_TOP TASK_SIZE
+#define STACK_TOP_MAX	STACK_TOP
 
 
 struct exec

Index: linux-2.6-2/include/asm-frv/mem-layout.h
===================================================================
@@ -60,6 +60,7 @@
  */
 #define BRK_BASE			__UL(2 * 1024 * 1024 + PAGE_SIZE)
 #define STACK_TOP			__UL(2 * 1024 * 1024)
+#define STACK_TOP_MAX	STACK_TOP
 
 /* userspace process size */
 #ifdef CONFIG_MMU

Index: linux-2.6-2/include/asm-h8300/a.out.h
===================================================================
@@ -20,6 +20,7 @@ struct exec
 #ifdef __KERNEL__
 
 #define STACK_TOP	TASK_SIZE
+#define STACK_TOP_MAX	STACK_TOP
 
 #endif
 

Index: linux-2.6-2/include/asm-i386/a.out.h
===================================================================
@@ -20,6 +20,7 @@ struct exec
 #ifdef __KERNEL__
 
 #define STACK_TOP	TASK_SIZE
+#define STACK_TOP_MAX	STACK_TOP
 
 #endif
 

Index: linux-2.6-2/include/asm-ia64/ustack.h
===================================================================
@@ -11,6 +11,7 @@
 /* The absolute hard limit for stack size is 1/2 of the mappable space in the region */
 #define MAX_USER_STACK_SIZE	(RGN_MAP_LIMIT/2)
 #define STACK_TOP		(0x6000000000000000UL + RGN_MAP_LIMIT)
+#define STACK_TOP_MAX		STACK_TOP
 #endif
 
 /* Make a default stack size of 2GiB */

Index: linux-2.6-2/include/asm-m32r/a.out.h
===================================================================
@@ -20,6 +20,7 @@ struct exec
 #ifdef __KERNEL__
 
 #define STACK_TOP	TASK_SIZE
+#define STACK_TOP_MAX	STACK_TOP
 
 #endif
 

Index: linux-2.6-2/include/asm-m68k/a.out.h
===================================================================
@@ -20,6 +20,7 @@ struct exec
 #ifdef __KERNEL__
 
 #define STACK_TOP	TASK_SIZE
+#define STACK_TOP_MAX	STACK_TOP
 
 #endif
 

Index: linux-2.6-2/include/asm-mips/a.out.h
===================================================================
@@ -40,6 +40,7 @@ struct exec
 #ifdef CONFIG_64BIT
 #define STACK_TOP	(current->thread.mflags & MF_32BIT_ADDR ? TASK_SIZE32 : TASK_SIZE)
 #endif
+#define STACK_TOP_MAX	TASK_SIZE
 
 #endif
 

Index: linux-2.6-2/include/asm-parisc/a.out.h
===================================================================
@@ -23,6 +23,7 @@ struct exec
  * prumpf */
 
 #define STACK_TOP	TASK_SIZE
+#define STACK_TOP_MAX	DEFAULT_TASK_SIZE
 
 #endif
 

Index: linux-2.6-2/include/asm-powerpc/a.out.h
===================================================================
@@ -26,9 +26,12 @@ struct exec
 #define STACK_TOP (test_thread_flag(TIF_32BIT) ? \
 		   STACK_TOP_USER32 : STACK_TOP_USER64)
 
+#define STACK_TOP_MAX STACK_TOP_USER64
+
 #else /* __powerpc64__ */
 
 #define STACK_TOP TASK_SIZE
+#define STACK_TOP_MAX	STACK_TOP
 
 #endif /* __powerpc64__ */
 #endif /* __KERNEL__ */

Index: linux-2.6-2/include/asm-s390/a.out.h
===================================================================
@@ -32,6 +32,7 @@ struct exec
 #ifdef __KERNEL__
 
 #define STACK_TOP	TASK_SIZE
+#define STACK_TOP_MAX	DEFAULT_TASK_SIZE
 
 #endif
 

Index: linux-2.6-2/include/asm-sh/a.out.h
===================================================================
@@ -20,6 +20,7 @@ struct exec
 #ifdef __KERNEL__
 
 #define STACK_TOP	TASK_SIZE
+#define STACK_TOP_MAX	STACK_TOP
 
 #endif
 

Index: linux-2.6-2/include/asm-sh64/a.out.h
===================================================================
@@ -31,6 +31,7 @@ struct exec
 #ifdef __KERNEL__
 
 #define STACK_TOP	TASK_SIZE
+#define STACK_TOP_MAX	STACK_TOP
 
 #endif
 

Index: linux-2.6-2/include/asm-sparc/a.out.h
===================================================================
@@ -92,6 +92,7 @@ struct relocation_info /* used when head
 #include <asm/page.h>
 
 #define STACK_TOP	(PAGE_OFFSET - PAGE_SIZE)
+#define STACK_TOP_MAX	STACK_TOP
 
 #endif /* __KERNEL__ */
 

Index: linux-2.6-2/include/asm-sparc64/a.out.h
===================================================================
@@ -101,6 +101,8 @@ struct relocation_info /* used when head
 #define STACK_TOP (test_thread_flag(TIF_32BIT) ? \
 		   STACK_TOP32 : STACK_TOP64)
 
+#define STACK_TOP_MAX STACK_TOP64
+
 #endif
 
 #endif /* !(__ASSEMBLY__) */

Index: linux-2.6-2/include/asm-um/a.out.h
===================================================================
@@ -5,6 +5,7 @@
 #include "choose-mode.h"
 
 #undef STACK_TOP
+#undef STACK_TOP_MAX
 
 extern unsigned long stacksizelim;
 

@@ -16,4 +17,6 @@ extern int honeypot;
 #define STACK_TOP \
 	CHOOSE_MODE((honeypot ? host_task_size : task_size), task_size)
 
+#define STACK_TOP_MAX	STACK_TOP
+
 #endif

Index: linux-2.6-2/include/asm-x86_64/a.out.h
===================================================================
@@ -21,7 +21,8 @@ struct exec
 
 #ifdef __KERNEL__
 #include <linux/thread_info.h>
-#define STACK_TOP TASK_SIZE
+#define STACK_TOP	TASK_SIZE
+#define STACK_TOP_MAX	TASK_SIZE64
 #endif
 
 #endif /* __A_OUT_GNU_H__ */

Index: linux-2.6-2/include/asm-xtensa/a.out.h
===================================================================
@@ -17,6 +17,7 @@
 /* Note: the kernel needs the a.out definitions, even if only ELF is used. */
 
 #define STACK_TOP	TASK_SIZE
+#define STACK_TOP_MAX	STACK_TOP
 
 struct exec
 {

Index: linux-2.6-2/kernel/auditsc.c
===================================================================
@@ -156,7 +156,7 @@ struct audit_aux_data_execve {
 	struct audit_aux_data	d;
 	int argc;
 	int envc;
-	char mem[0];
+	struct mm_struct *mm;
 };
 
 struct audit_aux_data_socketcall {

@@ -834,6 +834,55 @@ static int audit_log_pid_context(struct 
 	return rc;
 }
 
+static void audit_log_execve_info(struct audit_buffer *ab,
+		struct audit_aux_data_execve *axi)
+{
+	int i;
+	long len, ret;
+	const char __user *p = (const char __user *)axi->mm->arg_start;
+	char *buf;
+
+	if (axi->mm != current->mm)
+		return; /* execve failed, no additional info */
+
+	for (i = 0; i < axi->argc; i++, p += len) {
+		len = strnlen_user(p, MAX_ARG_PAGES*PAGE_SIZE);
+		/*
+		 * We just created this mm, if we can't find the strings
+		 * we just copied into it something is _very_ wrong. Similar
+		 * for strings that are too long, we should not have created
+		 * any.
+		 */
+		if (!len || len > MAX_ARG_STRLEN) {
+			WARN_ON(1);
+			send_sig(SIGKILL, current, 0);
+		}
+
+		buf = kmalloc(len, GFP_KERNEL);
+		if (!buf) {
+			audit_panic("out of memory for argv string\n");
+			break;
+		}
+
+		ret = copy_from_user(buf, p, len);
+		/*
+		 * There is no reason for this copy to be short. We just
+		 * copied them here, and the mm hasn't been exposed to user-
+		 * space yet.
+		 */
+		if (!ret) {
+			WARN_ON(1);
+			send_sig(SIGKILL, current, 0);
+		}
+
+		audit_log_format(ab, "a%d=", i);
+		audit_log_untrustedstring(ab, buf);
+		audit_log_format(ab, "\n");
+
+		kfree(buf);
+	}
+}
+
 static void audit_log_exit(struct audit_context *context, struct task_struct *tsk)
 {
 	int i, call_panic = 0;

@@ -974,13 +1023,7 @@ static void audit_log_exit(struct audit_
 
 		case AUDIT_EXECVE: {
 			struct audit_aux_data_execve *axi = (void *)aux;
-			int i;
-			const char *p;
-			for (i = 0, p = axi->mem; i < axi->argc; i++) {
-				audit_log_format(ab, "a%d=", i);
-				p = audit_log_untrustedstring(ab, p);
-				audit_log_format(ab, "\n");
-			}
+			audit_log_execve_info(ab, axi);
 			break; }
 
 		case AUDIT_SOCKETCALL: {

@@ -1824,32 +1867,31 @@ int __audit_ipc_set_perm(unsigned long q
 	return 0;
 }
 
+int audit_argv_kb = 32;
+
 int audit_bprm(struct linux_binprm *bprm)
 {
 	struct audit_aux_data_execve *ax;
 	struct audit_context *context = current->audit_context;
-	unsigned long p, next;
-	void *to;
 
 	if (likely(!audit_enabled || !context || context->dummy))
 		return 0;
 
-	ax = kmalloc(sizeof(*ax) + PAGE_SIZE * MAX_ARG_PAGES - bprm->p,
-				GFP_KERNEL);
+	/*
+	 * Even though the stack code doesn't limit the arg+env size any more,
+	 * the audit code requires that _all_ arguments be logged in a single
+	 * netlink skb. Hence cap it :-(
+	 */
+	if (bprm->argv_len > (audit_argv_kb << 10))
+		return -E2BIG;
+
+	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
 	if (!ax)
 		return -ENOMEM;
 
 	ax->argc = bprm->argc;
 	ax->envc = bprm->envc;
-	for (p = bprm->p, to = ax->mem; p < MAX_ARG_PAGES*PAGE_SIZE; p = next) {
-		struct page *page = bprm->page[p / PAGE_SIZE];
-		void *kaddr = kmap(page);
-		next = (p + PAGE_SIZE) & ~(PAGE_SIZE - 1);
-		memcpy(to, kaddr + (p & (PAGE_SIZE - 1)), next - p);
-		to += next - p;
-		kunmap(page);
-	}
-
+	ax->mm = bprm->mm;
 	ax->d.type = AUDIT_EXECVE;
 	ax->d.next = context->aux;
 	context->aux = (void *)ax;

Index: linux-2.6-2/fs/exec.c
===================================================================
@@ -1154,6 +1154,7 @@ int do_execve(char * filename,
 {
 	struct linux_binprm *bprm;
 	struct file *file;
+	unsigned long env_p;
 	int retval;
 	int i;
 

@@ -1208,9 +1209,11 @@ int do_execve(char * filename,
 	if (retval < 0)
 		goto out;
 
+	env_p = bprm->p;
 	retval = copy_strings(bprm->argc, argv, bprm);
 	if (retval < 0)
 		goto out;
+	bprm->argv_len = env_p - bprm->p;
 
 	retval = search_binary_handler(bprm,regs);
 	if (retval >= 0) {

Index: linux-2.6-2/include/linux/binfmts.h
===================================================================
@@ -40,6 +40,7 @@ struct linux_binprm{
 	unsigned interp_flags;
 	unsigned interp_data;
 	unsigned long loader, exec;
+	unsigned long argv_len;
 };
 
 #define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0

Index: linux-2.6-2/kernel/sysctl.c
===================================================================
@@ -81,6 +81,7 @@ extern int percpu_pagelist_fraction;
 extern int compat_log;
 extern int maps_protect;
 extern int sysctl_stat_interval;
+extern int audit_argv_kb;
 
 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 static int maxolduid = 65535;

@@ -711,6 +712,16 @@ static ctl_table kern_table[] = {
 		.proc_handler	= &proc_dointvec,
 	},
 #endif
+#ifdef CONFIG_AUDITSYSCALL
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "audit_argv_kb",
+		.data		= &audit_argv_kb,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+#endif
 
 	{ .ctl_name = 0 }
 };

Index: linux-2.6-2/arch/x86_64/ia32/ia32_binfmt.c
===================================================================
@@ -233,9 +233,6 @@ do {							\
 #define load_elf_binary load_elf32_binary
 
 #define ELF_PLAT_INIT(r, load_addr)	elf32_init(r)
-#define setup_arg_pages(bprm, stack_top, exec_stack) \
-	ia32_setup_arg_pages(bprm, stack_top, exec_stack)
-int ia32_setup_arg_pages(struct linux_binprm *bprm, unsigned long stack_top, int executable_stack);
 
 #undef start_thread
 #define start_thread(regs,new_rip,new_rsp) do { \

@@ -287,61 +284,6 @@ static void elf32_init(struct pt_regs *r
 	me->thread.es = __USER_DS;
 }
 
-int ia32_setup_arg_pages(struct linux_binprm *bprm, unsigned long stack_top,
-			 int executable_stack)
-{
-	unsigned long stack_base;
-	struct vm_area_struct *mpnt;
-	struct mm_struct *mm = current->mm;
-	int i, ret;
-
-	stack_base = stack_top - MAX_ARG_PAGES * PAGE_SIZE;
-	mm->arg_start = bprm->p + stack_base;
-
-	bprm->p += stack_base;
-	if (bprm->loader)
-		bprm->loader += stack_base;
-	bprm->exec += stack_base;
-
-	mpnt = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
-	if (!mpnt) 
-		return -ENOMEM; 
-
-	down_write(&mm->mmap_sem);
-	{
-		mpnt->vm_mm = mm;
-		mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
-		mpnt->vm_end = stack_top;
-		if (executable_stack == EXSTACK_ENABLE_X)
-			mpnt->vm_flags = VM_STACK_FLAGS |  VM_EXEC;
-		else if (executable_stack == EXSTACK_DISABLE_X)
-			mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC;
-		else
-			mpnt->vm_flags = VM_STACK_FLAGS;
- 		mpnt->vm_page_prot = (mpnt->vm_flags & VM_EXEC) ? 
- 			PAGE_COPY_EXEC : PAGE_COPY;
-		if ((ret = insert_vm_struct(mm, mpnt))) {
-			up_write(&mm->mmap_sem);
-			kmem_cache_free(vm_area_cachep, mpnt);
-			return ret;
-		}
-		mm->stack_vm = mm->total_vm = vma_pages(mpnt);
-	} 
-
-	for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
-		struct page *page = bprm->page[i];
-		if (page) {
-			bprm->page[i] = NULL;
-			install_arg_page(mpnt, page, stack_base);
-		}
-		stack_base += PAGE_SIZE;
-	}
-	up_write(&mm->mmap_sem);
-	
-	return 0;
-}
-EXPORT_SYMBOL(ia32_setup_arg_pages);
-
 #ifdef CONFIG_SYSCTL
 /* Register vsyscall32 into the ABI table */
 #include <linux/sysctl.h>

Index: linux-2.6-2/fs/binfmt_elf.c
===================================================================
@@ -148,6 +148,7 @@ create_elf_tables(struct linux_binprm *b
 	elf_addr_t *elf_info;
 	int ei_index = 0;
 	struct task_struct *tsk = current;
+	struct vm_area_struct *vma;
 
 	/*
 	 * If this architecture has a platform capability string, copy it

@@ -234,6 +235,15 @@ create_elf_tables(struct linux_binprm *b
 	sp = (elf_addr_t __user *)bprm->p;
 #endif
 
+
+	/*
+	 * Grow the stack manually; some architectures have a limit on how
+	 * far ahead a user-space access may be in order to grow the stack.
+	 */
+	vma = find_extend_vma(current->mm, bprm->p);
+	if (!vma)
+		return -EFAULT;
+
 	/* Now, let's put argc (and argv, envp if appropriate) on the stack */
 	if (__put_user(argc, sp++))
 		return -EFAULT;

@@ -254,8 +264,8 @@ create_elf_tables(struct linux_binprm *b
 		size_t len;
 		if (__put_user((elf_addr_t)p, argv++))
 			return -EFAULT;
-		len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
-		if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
+		len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
+		if (!len || len > MAX_ARG_STRLEN)
 			return 0;
 		p += len;
 	}

@@ -266,8 +276,8 @@ create_elf_tables(struct linux_binprm *b
 		size_t len;
 		if (__put_user((elf_addr_t)p, envp++))
 			return -EFAULT;
-		len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
-		if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
+		len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
+		if (!len || len > MAX_ARG_STRLEN)
 			return 0;
 		p += len;
 	}

@@ -826,10 +836,6 @@ static int load_elf_binary(struct linux_
 	}
 
 	/* OK, This is the point of no return */
-	current->mm->start_data = 0;
-	current->mm->end_data = 0;
-	current->mm->end_code = 0;
-	current->mm->mmap = NULL;
 	current->flags &= ~PF_FORKNOEXEC;
 	current->mm->def_flags = def_flags;
 

@@ -1051,9 +1057,13 @@ static int load_elf_binary(struct linux_
 
 	compute_creds(bprm);
 	current->flags &= ~PF_FORKNOEXEC;
-	create_elf_tables(bprm, &loc->elf_ex,
+	retval = create_elf_tables(bprm, &loc->elf_ex,
 			  (interpreter_type == INTERPRETER_AOUT),
 			  load_addr, interp_load_addr);
+	if (retval < 0) {
+		send_sig(SIGKILL, current, 0);
+		goto out;
+	}
 	/* N.B. passed_fileno might not be initialized? */
 	if (interpreter_type == INTERPRETER_AOUT)
 		current->mm->arg_start += strlen(passed_fileno) + 1;

Index: linux-2.6-2/fs/binfmt_elf_fdpic.c
===================================================================
@@ -621,8 +621,8 @@ static int create_elf_fdpic_tables(struc
 	p = (char __user *) current->mm->arg_start;
 	for (loop = bprm->argc; loop > 0; loop--) {
 		__put_user((elf_caddr_t) p, argv++);
-		len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
-		if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
+		len = strnlen_user(p, MAX_ARG_STRLEN);
+		if (!len || len > MAX_ARG_STRLEN)
 			return -EINVAL;
 		p += len;
 	}

@@ -633,8 +633,8 @@ static int create_elf_fdpic_tables(struc
 	current->mm->env_start = (unsigned long) p;
 	for (loop = bprm->envc; loop > 0; loop--) {
 		__put_user((elf_caddr_t)(unsigned long) p, envp++);
-		len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
-		if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
+		len = strnlen_user(p, MAX_ARG_STRLEN);
+		if (!len || len > MAX_ARG_STRLEN)
 			return -EINVAL;
 		p += len;
 	}

Index: linux-2.6-2/fs/binfmt_misc.c
===================================================================
@@ -126,7 +126,9 @@ static int load_misc_binary(struct linux
 		goto _ret;
 
 	if (!(fmt->flags & MISC_FMT_PRESERVE_ARGV0)) {
-		remove_arg_zero(bprm);
+		retval = remove_arg_zero(bprm);
+		if (retval)
+			goto _ret;
 	}
 
 	if (fmt->flags & MISC_FMT_OPEN_BINARY) {

Index: linux-2.6-2/fs/binfmt_script.c
===================================================================
@@ -67,7 +67,9 @@ static int load_script(struct linux_binp
 	 * This is done in reverse order, because of how the
 	 * user environment and arguments are stored.
 	 */
-	remove_arg_zero(bprm);
+	retval = remove_arg_zero(bprm);
+	if (retval)
+		return retval;
 	retval = copy_strings_kernel(1, &bprm->interp, bprm);
 	if (retval < 0) return retval; 
 	bprm->argc++;

209 lines not on this page · raw message

778 lines not on this page · raw message

Index: linux-2.6-2/include/linux/binfmts.h
===================================================================
@@ -6,11 +6,13 @@
 struct pt_regs;
 
 /*
- * MAX_ARG_PAGES defines the number of pages allocated for arguments
- * and envelope for the new program. 32 should suffice, this gives
- * a maximum env+arg of 128kB w/4KB pages!
+ * These are the maximum length and maximum number of strings passed to the
+ * execve() system call.  MAX_ARG_STRLEN is essentially random but serves to
+ * prevent the kernel from being unduly impacted by misaddressed pointers.
+ * MAX_ARG_STRINGS is chosen to fit in a signed 32-bit integer.
  */
-#define MAX_ARG_PAGES 32
+#define MAX_ARG_STRLEN (PAGE_SIZE * 32)
+#define MAX_ARG_STRINGS 0x7FFFFFFF
 
 /* sizeof(linux_binprm->buf) */
 #define BINPRM_BUF_SIZE 128

@@ -24,7 +26,12 @@ struct pt_regs;
  */
 struct linux_binprm{
 	char buf[BINPRM_BUF_SIZE];
+#ifdef CONFIG_MMU
+	struct vm_area_struct *vma;
+#else
+# define MAX_ARG_PAGES	32
 	struct page *page[MAX_ARG_PAGES];
+#endif
 	struct mm_struct *mm;
 	unsigned long p; /* current top of mem */
 	int sh_bang;

@@ -69,7 +76,7 @@ extern int register_binfmt(struct linux_
 extern int unregister_binfmt(struct linux_binfmt *);
 
 extern int prepare_binprm(struct linux_binprm *);
-extern void remove_arg_zero(struct linux_binprm *);
+extern int __must_check remove_arg_zero(struct linux_binprm *);
 extern int search_binary_handler(struct linux_binprm *,struct pt_regs *);
 extern int flush_old_exec(struct linux_binprm * bprm);
 

@@ -86,6 +93,7 @@ extern int suid_dumpable;
 extern int setup_arg_pages(struct linux_binprm * bprm,
 			   unsigned long stack_top,
 			   int executable_stack);
+extern int bprm_mm_init(struct linux_binprm *bprm);
 extern int copy_strings_kernel(int argc,char ** argv,struct linux_binprm *bprm);
 extern void compute_creds(struct linux_binprm *binprm);
 extern int do_coredump(long signr, int exit_code, struct pt_regs * regs);

Index: linux-2.6-2/include/linux/mm.h
===================================================================
@@ -815,7 +815,6 @@ static inline int handle_mm_fault(struct
 
 extern int make_pages_present(unsigned long addr, unsigned long end);
 extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
-void install_arg_page(struct vm_area_struct *, struct page *, unsigned long);
 
 int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start,
 		int len, int write, int force, struct page **pages, struct vm_area_struct **vmas);

@@ -832,9 +831,15 @@ int FASTCALL(set_page_dirty(struct page 
 int set_page_dirty_lock(struct page *page);
 int clear_page_dirty_for_io(struct page *page);
 
+extern unsigned long move_page_tables(struct vm_area_struct *vma,
+		unsigned long old_addr, struct vm_area_struct *new_vma,
+		unsigned long new_addr, unsigned long len);
 extern unsigned long do_mremap(unsigned long addr,
 			       unsigned long old_len, unsigned long new_len,
 			       unsigned long flags, unsigned long new_addr);
+extern int mprotect_fixup(struct vm_area_struct *vma,
+			  struct vm_area_struct **pprev, unsigned long start,
+			  unsigned long end, unsigned long newflags);
 
 /*
  * A callback you can register to apply pressure to ageable caches.

@@ -1159,6 +1164,8 @@ extern int expand_stack(struct vm_area_s
 #ifdef CONFIG_IA64
 extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
 #endif
+extern int expand_stack_downwards(struct vm_area_struct *vma,
+				  unsigned long address);
 
 /* Look up the first VMA which satisfies  addr < vm_end,  NULL if none. */
 extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);

83 lines not on this page · raw message

Index: linux-2.6-2/mm/mprotect.c
===================================================================
@@ -128,7 +128,7 @@ static void change_protection(struct vm_
 	flush_tlb_range(vma, start, end);
 }
 
-static int
+int
 mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
 	unsigned long start, unsigned long end, unsigned long newflags)
 {

77 lines not on this page · raw message

Index: linux-2.6-2/arch/x86_64/ia32/ia32_aout.c
===================================================================
@@ -404,7 +404,7 @@ beyond_if:
 
 	set_brk(current->mm->start_brk, current->mm->brk);
 
-	retval = ia32_setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT);
+	retval = setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT);
 	if (retval < 0) { 
 		/* Someone check-me: is this error path enough? */ 
 		send_sig(SIGKILL, current, 0); 

Index: linux-2.6-2/kernel/auditsc.c
===================================================================
@@ -846,7 +846,7 @@ static void audit_log_execve_info(struct
 		return; /* execve failed, no additional info */
 
 	for (i = 0; i < axi->argc; i++, p += len) {
-		len = strnlen_user(p, MAX_ARG_PAGES*PAGE_SIZE);
+		len = strnlen_user(p, MAX_ARG_STRLEN);
 		/*
 		 * We just created this mm, if we can't find the strings
 		 * we just copied into it something is _very_ wrong. Similar

Index: linux-2.6-2/mm/mremap.c
===================================================================
@@ -120,7 +120,7 @@ static void move_ptes(struct vm_area_str
 
 #define LATENCY_LIMIT	(64 * PAGE_SIZE)
 
-static unsigned long move_page_tables(struct vm_area_struct *vma,
+unsigned long move_page_tables(struct vm_area_struct *vma,
 		unsigned long old_addr, struct vm_area_struct *new_vma,
 		unsigned long new_addr, unsigned long len)
 {

Index: linux-2.6-2/fs/exec.c
===================================================================
@@ -272,6 +272,17 @@ static bool valid_arg_len(struct linux_b
 	return len <= MAX_ARG_STRLEN;
 }
 
+static int expand_arg_vma(struct linux_binprm *bprm)
+{
+	long size = (bprm->argc + bprm->envc + 2) * sizeof(void *);
+
+#ifdef CONFIG_STACK_GROWSUP
+#error I broke it
+#else
+	return expand_stack(bprm->vma, bprm->p - size);
+#endif
+}
+
 #else
 
 static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,

@@ -326,6 +337,11 @@ static bool valid_arg_len(struct linux_b
 	return len <= bprm->p;
 }
 
+static int expand_arg_vma(struct linux_binprm *bprm)
+{
+	return 0;
+}
+
 #endif /* CONFIG_MMU */
 
 /*

@@ -1385,6 +1401,10 @@ int do_execve(char * filename,
 		goto out;
 	bprm->argv_len = env_p - bprm->p;
 
+	retval = expand_arg_vma(bprm);
+	if (retval < 0)
+		goto out;
+
 	retval = search_binary_handler(bprm,regs);
 	if (retval >= 0) {
 		/* execve success */

Index: linux-2.6-2/fs/exec.c
===================================================================
@@ -199,6 +199,23 @@ static struct page *get_arg_page(struct 
 	if (ret <= 0)
 		return NULL;
 
+	if (write) {
+		struct rlimit *rlim = current->signal->rlim;
+		unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start;
+
+		/*
+		 * Limit to 1/4-th the stack size for the argv+env strings.
+		 * This ensures that:
+		 *  - the remaining binfmt code will not run out of stack space,
+		 *  - the program will have a reasonable amount of stack left
+		 *    to work from.
+		 */
+		if (size > rlim[RLIMIT_STACK].rlim_cur / 4) {
+			put_page(page);
+			return NULL;
+		}
+	}
+
 	return page;
 }