5459c164f0
When cap_bset suppresses some of the forced (fP) capabilities of a file, it is generally only safe to execute the program if it understands how to recognize it doesn't have enough privilege to work correctly. For legacy applications (fE!=0), which have no non-destructive way to determine that they are missing privilege, we fail to execute (EPERM) any executable that requires fP capabilities, but would otherwise get pP' < fP. This is a fail-safe permission check. For some discussion of why it is problematic for (legacy) privileged applications to run with less than the set of capabilities requested for them, see: http://userweb.kernel.org/~morgan/sendmail-capabilities-war-story.html With this iteration of this support, we do not include setuid-0 based privilege protection from the bounding set. That is, the admin can still (ab)use the bounding set to suppress the privileges of a setuid-0 program. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: cleanup] Signed-off-by: Andrew G. Morgan <morgan@kernel.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
105 lines
3.3 KiB
C
105 lines
3.3 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;
|
|
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)
|
|
|
|
|
|
/*
|
|
* 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 */
|