/* * binfmt_misc.c * * Copyright (C) 1997 Richard Günther * * binfmt_misc detects binaries via a magic or filename extension and invokes * a specified wrapper. This should obsolete binfmt_java, binfmt_em86 and * binfmt_mz. * * 1997-04-25 first version * [...] * 1997-05-19 cleanup * 1997-06-26 hpa: pass the real filename rather than argv[0] * 1997-06-30 minor cleanup * 1997-08-09 removed extension stripping, locking cleanup * 2001-02-28 AV: rewritten into something that resembles C. Original didn't. */ #include <linux/module.h>#include <linux/init.h>#include <linux/sched.h>#include <linux/magic.h>#include <linux/binfmts.h>#include <linux/slab.h>#include <linux/ctype.h>#include <linux/file.h>#include <linux/pagemap.h>#include <linux/namei.h>#include <linux/mount.h>#include <linux/syscalls.h>#include <linux/fs.h> #include <asm/uaccess.h> enum { VERBOSE_STATUS = 1 /* make it zero to save 400 bytes kernel memory */}; static LIST_HEAD(entries);static int enabled = 1; enum {Enabled, Magic};#define MISC_FMT_PRESERVE_ARGV0 (1<<31)#define MISC_FMT_OPEN_BINARY (1<<30)#define MISC_FMT_CREDENTIALS (1<<29) typedef struct { struct list_head list; unsigned long flags; /* type, status, etc. */ int offset; /* offset of magic */ int size; /* size of magic/mask */ char *magic; /* magic or filename extension */ char *mask; /* mask, NULL for exact match */ char *interpreter; /* filename of interpreter */ char *name; struct dentry *dentry;} Node; static DEFINE_RWLOCK(entries_lock);static struct file_system_type bm_fs_type;static struct vfsmount *bm_mnt;static int entry_count; /* * Check if we support the binfmt * if we do, return the node, else NULL * locking is done in load_misc_binary */static Node *check_file(struct linux_binprm *bprm){ char *p = strrchr(bprm->interp, '.'); struct list_head *l; list_for_each(l, &entries) { Node *e = list_entry(l, Node, list); char *s; int j; if (!test_bit(Enabled, &e->flags)) continue; if (!test_bit(Magic, &e->flags)) { if (p && !strcmp(e->magic, p + 1)) return e; continue; } s = bprm->buf + e->offset; if (e->mask) { for (j = 0; j < e->size; j++) if ((*s++ ^ e->magic[j]) & e->mask[j]) break; } else { for (j = 0; j < e->size; j++) if ((*s++ ^ e->magic[j])) break; } if (j == e->size) return e; } return NULL;} /* * the loader itself */static int load_misc_binary(struct linux_binprm *bprm, struct pt_regs *regs){ Node *fmt; struct file * interp_file = NULL; char iname[BINPRM_BUF_SIZE]; const char *iname_addr = iname; int retval; int fd_binary = -1; retval = -ENOEXEC; if (!enabled) goto _ret; retval = -ENOEXEC; if (bprm->recursion_depth > BINPRM_MAX_RECURSION) goto _ret; /* to keep locking time low, we copy the interpreter string */ read_lock(&entries_lock); fmt = check_file(bprm); if (fmt) strlcpy(iname, fmt->interpreter, BINPRM_BUF_SIZE); read_unlock(&entries_lock); if (!fmt) goto _ret; if (!(fmt->flags & MISC_FMT_PRESERVE_ARGV0)) { retval = remove_arg_zero(bprm); if (retval) goto _ret; } if (fmt->flags & MISC_FMT_OPEN_BINARY) { /* if the binary should be opened on behalf of the * interpreter than keep it open and assign descriptor * to it */ fd_binary = get_unused_fd(); if (fd_binary < 0) { retval = fd_binary; goto _ret; } fd_install(fd_binary, bprm->file); /* if the binary is not readable than enforce mm->dumpable=0 regardless of the interpreter's permissions */ would_dump(bprm, bprm->file); allow_write_access(bprm->file); bprm->file = NULL; /* mark the bprm that fd should be passed to interp */ bprm->interp_flags |= BINPRM_FLAGS_EXECFD; bprm->interp_data = fd_binary; } else { allow_write_access(bprm->file); fput(bprm->file); bprm->file = NULL; } /* make argv[1] be the path to the binary */ retval = copy_strings_kernel (1, &bprm->interp, bprm); if (retval < 0) goto _error; bprm->argc++; /* add the interp as argv[0] */ retval = copy_strings_kernel (1, &iname_addr, bprm); if (retval < 0) goto _error; bprm->argc ++; bprm->interp = iname; /* for binfmt_script */ interp_file = open_exec (iname); retval = PTR_ERR (interp_file); if (IS_ERR (interp_file)) goto _error; bprm->file = interp_file; if (fmt->flags & MISC_FMT_CREDENTIALS) { /* * No need to call prepare_binprm(), it's already been * done. bprm->buf is stale, update from interp_file. */ memset(bprm->buf, 0, BINPRM_BUF_SIZE); retval = kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE); } else retval = prepare_binprm (bprm); if (retval < 0) goto _error; bprm->recursion_depth++; retval = search_binary_handler (bprm, regs); if (retval < 0) goto _error; _ret: return retval;_error: if (fd_binary > 0) sys_close(fd_binary); bprm->interp_flags = 0; bprm->interp_data = 0; goto _ret;} /* Command parsers */ /* * parses and copies one argument enclosed in del from *sp to *dp, * recognising the \x special. * returns pointer to the copied argument or NULL in case of an * error (and sets err) or null argument length. */static char *scanarg(char *s, char del){ char c; while ((c = *s++) != del) { if (c == '\\' && *s == 'x') { s++; if (!isxdigit(*s++)) return NULL; if (!isxdigit(*s++)) return NULL; } } return s;} static int unquote(char *from){ char c = 0, *s = from, *p = from; while ((c = *s++) != '\0') { if (c == '\\' && *s == 'x') { s++; c = toupper(*s++); *p = (c - (isdigit(c) ? '0' : 'A' - 10)) << 4; c = toupper(*s++); *p++ |= c - (isdigit(c) ? '0' : 'A' - 10); continue; } *p++ = c; } return p - from;} static char * check_special_flags (char * sfs, Node * e){ char * p = sfs; int cont = 1; /* special flags */ while (cont) { switch (*p) { case 'P': p++; e->flags |= MISC_FMT_PRESERVE_ARGV0; break; case 'O': p++; e->flags |= MISC_FMT_OPEN_BINARY; break; case 'C': p++; /* this flags also implies the open-binary flag */ e->flags |= (MISC_FMT_CREDENTIALS | MISC_FMT_OPEN_BINARY); break; default: cont = 0; } } return p;}/* * This registers a new binary format, it recognises the syntax * ':name:type:offset:magic:mask:interpreter:flags' * where the ':' is the IFS, that can be chosen with the first char */static Node *create_entry(const char __user *buffer, size_t count){ Node *e; int memsize, err; char *buf, *p; char del; /* some sanity checks */ err = -EINVAL; if ((count < 11) || (count > 256)) goto out; err = -ENOMEM; memsize = sizeof(Node) + count + 8; e = kmalloc(memsize, GFP_USER); if (!e) goto out; p = buf = (char *)e + sizeof(Node); memset(e, 0, sizeof(Node)); if (copy_from_user(buf, buffer, count)) goto Efault; del = *p++; /* delimeter */ memset(buf+count, del, 8); e->name = p; p = strchr(p, del); if (!p) goto Einval; *p++ = '\0'; if (!e->name[0] || !strcmp(e->name, ".") || !strcmp(e->name, "..") || strchr(e->name, '/')) goto Einval; switch (*p++) { case 'E': e->flags = 1<<Enabled; break; case 'M': e->flags = (1<<Enabled) | (1<<Magic); break; default: goto Einval; } if (*p++ != del) goto Einval; if (test_bit(Magic, &e->flags)) { char *s = strchr(p, del); if (!s) goto Einval; *s++ = '\0'; e->offset = simple_strtoul(p, &p, 10); if (*p++) goto Einval; e->magic = p; p = scanarg(p, del); if (!p) goto Einval; p[-1] = '\0'; if (!e->magic[0]) goto Einval; e->mask = p; p = scanarg(p, del); if (!p) goto Einval; p[-1] = '\0'; if (!e->mask[0]) e->mask = NULL; e->size = unquote(e->magic); if (e->mask && unquote(e->mask) != e->size) goto Einval; if (e->size + e->offset > BINPRM_BUF_SIZE) goto Einval; } else { p = strchr(p, del); if (!p) goto Einval; *p++ = '\0'; e->magic = p; p = strchr(p, del); if (!p) goto Einval; *p++ = '\0'; if (!e->magic[0] || strchr(e->magic, '/')) goto Einval; p = strchr(p, del); if (!p) goto Einval; *p++ = '\0'; } e->interpreter = p; p = strchr(p, del); if (!p) goto Einval; *p++ = '\0'; if (!e->interpreter[0]) goto Einval; p = check_special_flags (p, e); if (*p == '\n') p++; if (p != buf + count) goto Einval; return e; out: return ERR_PTR(err); Efault: kfree(e); return ERR_PTR(-EFAULT);Einval: kfree(e); return ERR_PTR(-EINVAL);} /* * Set status of entry/binfmt_misc: * '1' enables, '0' disables and '-1' clears entry/binfmt_misc */static int parse_command(const char __user *buffer, size_t count){ char s[4]; if (!count) return 0; if (count > 3) return -EINVAL; if (copy_from_user(s, buffer, count)) return -EFAULT; if (s[count-1] == '\n') count--; if (count == 1 && s[0] == '0') return 1; if (count == 1 && s[0] == '1') return 2; if (count == 2 && s[0] == '-' && s[1] == '1') return 3; return -EINVAL;} /* generic stuff */ static void entry_status(Node *e, char *page){ char *dp; char *status = "disabled"; const char * flags = "flags: "; if (test_bit(Enabled, &e->flags)) status = "enabled"; if (!VERBOSE_STATUS) { sprintf(page, "%s\n", status); return; } sprintf(page, "%s\ninterpreter %s\n", status, e->interpreter); dp = page + strlen(page); /* print the special flags */ sprintf (dp, "%s", flags); dp += strlen (flags); if (e->flags & MISC_FMT_PRESERVE_ARGV0) { *dp ++ = 'P'; } if (e->flags & MISC_FMT_OPEN_BINARY) { *dp ++ = 'O'; } if (e->flags & MISC_FMT_CREDENTIALS) { *dp ++ = 'C'; } *dp ++ = '\n'; if (!test_bit(Magic, &e->flags)) { sprintf(dp, "extension .%s\n", e->magic); } else { int i; sprintf(dp, "offset %i\nmagic ", e->offset); dp = page + strlen(page); for (i = 0; i < e->size; i++) { sprintf(dp, "%02x", 0xff & (int) (e->magic[i])); dp += 2; } if (e->mask) { sprintf(dp, "\nmask "); dp += 6; for (i = 0; i < e->size; i++) { sprintf(dp, "%02x", 0xff & (int) (e->mask[i])); dp += 2; } } *dp++ = '\n'; *dp = '\0'; }} static struct inode *bm_get_inode(struct super_block *sb, int mode){ struct inode * inode = new_inode(sb); if (inode) { inode->i_ino = get_next_ino(); inode->i_mode = mode; inode->i_atime = inode->i_mtime = inode->i_ctime =Lines 1–500 of 743. 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/* * binfmt_misc.c * * Copyright (C) 1997 Richard Günther * * binfmt_misc detects binaries via a magic or filename extension and invokes * a specified wrapper. This should obsolete binfmt_java, binfmt_em86 and * binfmt_mz. * * 1997-04-25 first version * [...] * 1997-05-19 cleanup * 1997-06-26 hpa: pass the real filename rather than argv[0] * 1997-06-30 minor cleanup * 1997-08-09 removed extension stripping, locking cleanup * 2001-02-28 AV: rewritten into something that resembles C. Original didn't. */ #include <linux/module.h> #include <linux/init.h> #include <linux/sched.h> #include <linux/magic.h> #include <linux/binfmts.h> #include <linux/slab.h> #include <linux/ctype.h> #include <linux/file.h> #include <linux/pagemap.h> #include <linux/namei.h> #include <linux/mount.h> #include <linux/syscalls.h> #include <linux/fs.h> #include <asm/uaccess.h> enum { VERBOSE_STATUS = 1 /* make it zero to save 400 bytes kernel memory */ }; static LIST_HEAD(entries); static int enabled = 1; enum {Enabled, Magic}; #define MISC_FMT_PRESERVE_ARGV0 (1<<31) #define MISC_FMT_OPEN_BINARY (1<<30) #define MISC_FMT_CREDENTIALS (1<<29) typedef struct { struct list_head list; unsigned long flags; /* type, status, etc. */ int offset; /* offset of magic */ int size; /* size of magic/mask */ char *magic; /* magic or filename extension */ char *mask; /* mask, NULL for exact match */ char *interpreter; /* filename of interpreter */ char *name; struct dentry *dentry; } Node; static DEFINE_RWLOCK(entries_lock); static struct file_system_type bm_fs_type; static struct vfsmount *bm_mnt; static int entry_count; /* * Check if we support the binfmt * if we do, return the node, else NULL * locking is done in load_misc_binary */ static Node *check_file(struct linux_binprm *bprm) { char *p = strrchr(bprm->interp, '.'); struct list_head *l; list_for_each(l, &entries) { Node *e = list_entry(l, Node, list); char *s; int j; if (!test_bit(Enabled, &e->flags)) continue; if (!test_bit(Magic, &e->flags)) { if (p && !strcmp(e->magic, p + 1)) return e; continue; } s = bprm->buf + e->offset; if (e->mask) { for (j = 0; j < e->size; j++) if ((*s++ ^ e->magic[j]) & e->mask[j]) break; } else { for (j = 0; j < e->size; j++) if ((*s++ ^ e->magic[j])) break; } if (j == e->size) return e; } return NULL; } /* * the loader itself */ static int load_misc_binary(struct linux_binprm *bprm, struct pt_regs *regs) { Node *fmt; struct file * interp_file = NULL; char iname[BINPRM_BUF_SIZE]; const char *iname_addr = iname; int retval; int fd_binary = -1; retval = -ENOEXEC; if (!enabled) goto _ret; retval = -ENOEXEC; if (bprm->recursion_depth > BINPRM_MAX_RECURSION) goto _ret; /* to keep locking time low, we copy the interpreter string */ read_lock(&entries_lock); fmt = check_file(bprm); if (fmt) strlcpy(iname, fmt->interpreter, BINPRM_BUF_SIZE); read_unlock(&entries_lock); if (!fmt) goto _ret; if (!(fmt->flags & MISC_FMT_PRESERVE_ARGV0)) { retval = remove_arg_zero(bprm); if (retval) goto _ret; } if (fmt->flags & MISC_FMT_OPEN_BINARY) { /* if the binary should be opened on behalf of the * interpreter than keep it open and assign descriptor * to it */ fd_binary = get_unused_fd(); if (fd_binary < 0) { retval = fd_binary; goto _ret; } fd_install(fd_binary, bprm->file); /* if the binary is not readable than enforce mm->dumpable=0 regardless of the interpreter's permissions */ would_dump(bprm, bprm->file); allow_write_access(bprm->file); bprm->file = NULL; /* mark the bprm that fd should be passed to interp */ bprm->interp_flags |= BINPRM_FLAGS_EXECFD; bprm->interp_data = fd_binary; } else { allow_write_access(bprm->file); fput(bprm->file); bprm->file = NULL; } /* make argv[1] be the path to the binary */ retval = copy_strings_kernel (1, &bprm->interp, bprm); if (retval < 0) goto _error; bprm->argc++; /* add the interp as argv[0] */ retval = copy_strings_kernel (1, &iname_addr, bprm); if (retval < 0) goto _error; bprm->argc ++; bprm->interp = iname; /* for binfmt_script */ interp_file = open_exec (iname); retval = PTR_ERR (interp_file); if (IS_ERR (interp_file)) goto _error; bprm->file = interp_file; if (fmt->flags & MISC_FMT_CREDENTIALS) { /* * No need to call prepare_binprm(), it's already been * done. bprm->buf is stale, update from interp_file. */ memset(bprm->buf, 0, BINPRM_BUF_SIZE); retval = kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE); } else retval = prepare_binprm (bprm); if (retval < 0) goto _error; bprm->recursion_depth++; retval = search_binary_handler (bprm, regs); if (retval < 0) goto _error; _ret: return retval; _error: if (fd_binary > 0) sys_close(fd_binary); bprm->interp_flags = 0; bprm->interp_data = 0; goto _ret; } /* Command parsers */ /* * parses and copies one argument enclosed in del from *sp to *dp, * recognising the \x special. * returns pointer to the copied argument or NULL in case of an * error (and sets err) or null argument length. */ static char *scanarg(char *s, char del) { char c; while ((c = *s++) != del) { if (c == '\\' && *s == 'x') { s++; if (!isxdigit(*s++)) return NULL; if (!isxdigit(*s++)) return NULL; } } return s; } static int unquote(char *from) { char c = 0, *s = from, *p = from; while ((c = *s++) != '\0') { if (c == '\\' && *s == 'x') { s++; c = toupper(*s++); *p = (c - (isdigit(c) ? '0' : 'A' - 10)) << 4; c = toupper(*s++); *p++ |= c - (isdigit(c) ? '0' : 'A' - 10); continue; } *p++ = c; } return p - from; } static char * check_special_flags (char * sfs, Node * e) { char * p = sfs; int cont = 1; /* special flags */ while (cont) { switch (*p) { case 'P': p++; e->flags |= MISC_FMT_PRESERVE_ARGV0; break; case 'O': p++; e->flags |= MISC_FMT_OPEN_BINARY; break; case 'C': p++; /* this flags also implies the open-binary flag */ e->flags |= (MISC_FMT_CREDENTIALS | MISC_FMT_OPEN_BINARY); break; default: cont = 0; } } return p; } /* * This registers a new binary format, it recognises the syntax * ':name:type:offset:magic:mask:interpreter:flags' * where the ':' is the IFS, that can be chosen with the first char */ static Node *create_entry(const char __user *buffer, size_t count) { Node *e; int memsize, err; char *buf, *p; char del; /* some sanity checks */ err = -EINVAL; if ((count < 11) || (count > 256)) goto out; err = -ENOMEM; memsize = sizeof(Node) + count + 8; e = kmalloc(memsize, GFP_USER); if (!e) goto out; p = buf = (char *)e + sizeof(Node); memset(e, 0, sizeof(Node)); if (copy_from_user(buf, buffer, count)) goto Efault; del = *p++; /* delimeter */ memset(buf+count, del, 8); e->name = p; p = strchr(p, del); if (!p) goto Einval; *p++ = '\0'; if (!e->name[0] || !strcmp(e->name, ".") || !strcmp(e->name, "..") || strchr(e->name, '/')) goto Einval; switch (*p++) { case 'E': e->flags = 1<<Enabled; break; case 'M': e->flags = (1<<Enabled) | (1<<Magic); break; default: goto Einval; } if (*p++ != del) goto Einval; if (test_bit(Magic, &e->flags)) { char *s = strchr(p, del); if (!s) goto Einval; *s++ = '\0'; e->offset = simple_strtoul(p, &p, 10); if (*p++) goto Einval; e->magic = p; p = scanarg(p, del); if (!p) goto Einval; p[-1] = '\0'; if (!e->magic[0]) goto Einval; e->mask = p; p = scanarg(p, del); if (!p) goto Einval; p[-1] = '\0'; if (!e->mask[0]) e->mask = NULL; e->size = unquote(e->magic); if (e->mask && unquote(e->mask) != e->size) goto Einval; if (e->size + e->offset > BINPRM_BUF_SIZE) goto Einval; } else { p = strchr(p, del); if (!p) goto Einval; *p++ = '\0'; e->magic = p; p = strchr(p, del); if (!p) goto Einval; *p++ = '\0'; if (!e->magic[0] || strchr(e->magic, '/')) goto Einval; p = strchr(p, del); if (!p) goto Einval; *p++ = '\0'; } e->interpreter = p; p = strchr(p, del); if (!p) goto Einval; *p++ = '\0'; if (!e->interpreter[0]) goto Einval; p = check_special_flags (p, e); if (*p == '\n') p++; if (p != buf + count) goto Einval; return e; out: return ERR_PTR(err); Efault: kfree(e); return ERR_PTR(-EFAULT); Einval: kfree(e); return ERR_PTR(-EINVAL); } /* * Set status of entry/binfmt_misc: * '1' enables, '0' disables and '-1' clears entry/binfmt_misc */ static int parse_command(const char __user *buffer, size_t count) { char s[4]; if (!count) return 0; if (count > 3) return -EINVAL; if (copy_from_user(s, buffer, count)) return -EFAULT; if (s[count-1] == '\n') count--; if (count == 1 && s[0] == '0') return 1; if (count == 1 && s[0] == '1') return 2; if (count == 2 && s[0] == '-' && s[1] == '1') return 3; return -EINVAL; } /* generic stuff */ static void entry_status(Node *e, char *page) { char *dp; char *status = "disabled"; const char * flags = "flags: "; if (test_bit(Enabled, &e->flags)) status = "enabled"; if (!VERBOSE_STATUS) { sprintf(page, "%s\n", status); return; } sprintf(page, "%s\ninterpreter %s\n", status, e->interpreter); dp = page + strlen(page); /* print the special flags */ sprintf (dp, "%s", flags); dp += strlen (flags); if (e->flags & MISC_FMT_PRESERVE_ARGV0) { *dp ++ = 'P'; } if (e->flags & MISC_FMT_OPEN_BINARY) { *dp ++ = 'O'; } if (e->flags & MISC_FMT_CREDENTIALS) { *dp ++ = 'C'; } *dp ++ = '\n'; if (!test_bit(Magic, &e->flags)) { sprintf(dp, "extension .%s\n", e->magic); } else { int i; sprintf(dp, "offset %i\nmagic ", e->offset); dp = page + strlen(page); for (i = 0; i < e->size; i++) { sprintf(dp, "%02x", 0xff & (int) (e->magic[i])); dp += 2; } if (e->mask) { sprintf(dp, "\nmask "); dp += 6; for (i = 0; i < e->size; i++) { sprintf(dp, "%02x", 0xff & (int) (e->mask[i])); dp += 2; } } *dp++ = '\n'; *dp = '\0'; } } static struct inode *bm_get_inode(struct super_block *sb, int mode) { struct inode * inode = new_inode(sb); if (inode) { inode->i_ino = get_next_ino(); inode->i_mode = mode; inode->i_atime = inode->i_mtime = inode->i_ctime =