linux_dsm_epyc7002/include/linux/binfmts.h
Kirill A. Shutemov bf2a9a3963 Allow recursion in binfmt_script and binfmt_misc
binfmt_script and binfmt_misc disallow recursion to avoid stack overflow
using sh_bang and misc_bang.  It causes problem in some cases:

$ echo '#!/bin/ls' > /tmp/t0
$ echo '#!/tmp/t0' > /tmp/t1
$ echo '#!/tmp/t1' > /tmp/t2
$ chmod +x /tmp/t*
$ /tmp/t2
zsh: exec format error: /tmp/t2

Similar problem with binfmt_misc.

This patch introduces field 'recursion_depth' into struct linux_binprm to
track recursion level in binfmt_misc and binfmt_script.  If recursion
level more then BINPRM_MAX_RECURSION it generates -ENOEXEC.

[akpm@linux-foundation.org: make linux_binprm.recursion_depth a uint]
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 11:21:38 -07:00

111 lines
3.4 KiB
C

#ifndef _LINUX_BINFMTS_H
#define _LINUX_BINFMTS_H
#include <linux/capability.h>
struct pt_regs;
/*
* 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_STRLEN (PAGE_SIZE * 32)
#define MAX_ARG_STRINGS 0x7FFFFFFF
/* sizeof(linux_binprm->buf) */
#define BINPRM_BUF_SIZE 128
#ifdef __KERNEL__
#define CORENAME_MAX_SIZE 128
/*
* This structure is used to hold the arguments that are used when loading binaries.
*/
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 */
unsigned int sh_bang:1,
misc_bang:1;
#ifdef __alpha__
unsigned int taso:1;
#endif
unsigned int recursion_depth;
struct file * file;
int e_uid, e_gid;
kernel_cap_t cap_post_exec_permitted;
bool cap_effective;
void *security;
int argc, envc;
char * filename; /* Name of binary as seen by procps */
char * interp; /* Name of the binary really executed. Most
of the time same as filename, but could be
different for binfmt_{misc,script} */
unsigned interp_flags;
unsigned interp_data;
unsigned long loader, exec;
};
#define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0
#define BINPRM_FLAGS_ENFORCE_NONDUMP (1 << BINPRM_FLAGS_ENFORCE_NONDUMP_BIT)
/* fd of the binary should be passed to the interpreter */
#define BINPRM_FLAGS_EXECFD_BIT 1
#define BINPRM_FLAGS_EXECFD (1 << BINPRM_FLAGS_EXECFD_BIT)
#define BINPRM_MAX_RECURSION 4
/*
* This structure defines the functions that are used to load the binary formats that
* linux accepts.
*/
struct linux_binfmt {
struct list_head lh;
struct module *module;
int (*load_binary)(struct linux_binprm *, struct pt_regs * regs);
int (*load_shlib)(struct file *);
int (*core_dump)(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
unsigned long min_coredump; /* minimal dump size */
int hasvdso;
};
extern int register_binfmt(struct linux_binfmt *);
extern void unregister_binfmt(struct linux_binfmt *);
extern int prepare_binprm(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);
extern int suid_dumpable;
#define SUID_DUMP_DISABLE 0 /* No setuid dumping */
#define SUID_DUMP_USER 1 /* Dump as user of process */
#define SUID_DUMP_ROOT 2 /* Dump as root */
/* Stack area protections */
#define EXSTACK_DEFAULT 0 /* Whatever the arch defaults to */
#define EXSTACK_DISABLE_X 1 /* Disable executable stacks */
#define EXSTACK_ENABLE_X 2 /* Enable executable stacks */
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);
extern int set_binfmt(struct linux_binfmt *new);
extern void free_bprm(struct linux_binprm *);
#endif /* __KERNEL__ */
#endif /* _LINUX_BINFMTS_H */