From c8c57e842720d8cc92ac8607f2d1c16d92314573 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Thu, 3 Jun 2010 20:36:43 +0900 Subject: TOMOYO: Support longer pathname. Allow pathnames longer than 4000 bytes. Signed-off-by: Tetsuo Handa Signed-off-by: James Morris --- security/tomoyo/realpath.c | 214 ++++++++++++++++++++++++--------------------- 1 file changed, 113 insertions(+), 101 deletions(-) (limited to 'security/tomoyo/realpath.c') diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c index 1fd685a94ad1..153fa23a05cc 100644 --- a/security/tomoyo/realpath.c +++ b/security/tomoyo/realpath.c @@ -12,141 +12,153 @@ #include #include #include +#include #include "common.h" /** * tomoyo_encode: Convert binary string to ascii string. * - * @buffer: Buffer for ASCII string. - * @buflen: Size of @buffer. - * @str: Binary string. + * @str: String in binary format. * - * Returns 0 on success, -ENOMEM otherwise. + * Returns pointer to @str in ascii format on success, NULL otherwise. + * + * This function uses kzalloc(), so caller must kfree() if this function + * didn't return NULL. */ -int tomoyo_encode(char *buffer, int buflen, const char *str) +char *tomoyo_encode(const char *str) { - while (1) { - const unsigned char c = *(unsigned char *) str++; + int len = 0; + const char *p = str; + char *cp; + char *cp0; - if (tomoyo_is_valid(c)) { - if (--buflen <= 0) - break; - *buffer++ = (char) c; - if (c != '\\') - continue; - if (--buflen <= 0) - break; - *buffer++ = (char) c; - continue; - } - if (!c) { - if (--buflen <= 0) - break; - *buffer = '\0'; - return 0; + if (!p) + return NULL; + while (*p) { + const unsigned char c = *p++; + if (c == '\\') + len += 2; + else if (c > ' ' && c < 127) + len++; + else + len += 4; + } + len++; + /* Reserve space for appending "/". */ + cp = kzalloc(len + 10, GFP_NOFS); + if (!cp) + return NULL; + cp0 = cp; + p = str; + while (*p) { + const unsigned char c = *p++; + + if (c == '\\') { + *cp++ = '\\'; + *cp++ = '\\'; + } else if (c > ' ' && c < 127) { + *cp++ = c; + } else { + *cp++ = '\\'; + *cp++ = (c >> 6) + '0'; + *cp++ = ((c >> 3) & 7) + '0'; + *cp++ = (c & 7) + '0'; } - buflen -= 4; - if (buflen <= 0) - break; - *buffer++ = '\\'; - *buffer++ = (c >> 6) + '0'; - *buffer++ = ((c >> 3) & 7) + '0'; - *buffer++ = (c & 7) + '0'; } - return -ENOMEM; + return cp0; } /** - * tomoyo_realpath_from_path2 - Returns realpath(3) of the given dentry but ignores chroot'ed root. + * tomoyo_realpath_from_path - Returns realpath(3) of the given pathname but ignores chroot'ed root. * - * @path: Pointer to "struct path". - * @newname: Pointer to buffer to return value in. - * @newname_len: Size of @newname. + * @path: Pointer to "struct path". * - * Returns 0 on success, negative value otherwise. + * Returns the realpath of the given @path on success, NULL otherwise. * * If dentry is a directory, trailing '/' is appended. * Characters out of 0x20 < c < 0x7F range are converted to * \ooo style octal string. * Character \ is converted to \\ string. + * + * These functions use kzalloc(), so the caller must call kfree() + * if these functions didn't return NULL. */ -int tomoyo_realpath_from_path2(struct path *path, char *newname, - int newname_len) +char *tomoyo_realpath_from_path(struct path *path) { - int error = -ENOMEM; + char *buf = NULL; + char *name = NULL; + unsigned int buf_len = PAGE_SIZE / 2; struct dentry *dentry = path->dentry; - char *sp; - - if (!dentry || !path->mnt || !newname || newname_len <= 2048) - return -EINVAL; - if (dentry->d_op && dentry->d_op->d_dname) { + bool is_dir; + if (!dentry) + return NULL; + is_dir = dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode); + while (1) { + struct path ns_root = { .mnt = NULL, .dentry = NULL }; + char *pos; + buf_len <<= 1; + kfree(buf); + buf = kmalloc(buf_len, GFP_NOFS); + if (!buf) + break; + /* Get better name for socket. */ + if (dentry->d_sb && dentry->d_sb->s_magic == SOCKFS_MAGIC) { + struct inode *inode = dentry->d_inode; + struct socket *sock = inode ? SOCKET_I(inode) : NULL; + struct sock *sk = sock ? sock->sk : NULL; + if (sk) { + snprintf(buf, buf_len - 1, "socket:[family=%u:" + "type=%u:protocol=%u]", sk->sk_family, + sk->sk_type, sk->sk_protocol); + } else { + snprintf(buf, buf_len - 1, "socket:[unknown]"); + } + name = tomoyo_encode(buf); + break; + } /* For "socket:[\$]" and "pipe:[\$]". */ - static const int offset = 1536; - sp = dentry->d_op->d_dname(dentry, newname + offset, - newname_len - offset); - } else { - struct path ns_root = {.mnt = NULL, .dentry = NULL}; - + if (dentry->d_op && dentry->d_op->d_dname) { + pos = dentry->d_op->d_dname(dentry, buf, buf_len - 1); + if (IS_ERR(pos)) + continue; + name = tomoyo_encode(pos); + break; + } + /* If we don't have a vfsmount, we can't calculate. */ + if (!path->mnt) + break; spin_lock(&dcache_lock); /* go to whatever namespace root we are under */ - sp = __d_path(path, &ns_root, newname, newname_len); + pos = __d_path(path, &ns_root, buf, buf_len); spin_unlock(&dcache_lock); /* Prepend "/proc" prefix if using internal proc vfs mount. */ - if (!IS_ERR(sp) && (path->mnt->mnt_flags & MNT_INTERNAL) && + if (!IS_ERR(pos) && (path->mnt->mnt_flags & MNT_INTERNAL) && (path->mnt->mnt_sb->s_magic == PROC_SUPER_MAGIC)) { - sp -= 5; - if (sp >= newname) - memcpy(sp, "/proc", 5); + pos -= 5; + if (pos >= buf) + memcpy(pos, "/proc", 5); else - sp = ERR_PTR(-ENOMEM); - } - } - if (IS_ERR(sp)) - error = PTR_ERR(sp); - else - error = tomoyo_encode(newname, sp - newname, sp); - /* Append trailing '/' if dentry is a directory. */ - if (!error && dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode) - && *newname) { - sp = newname + strlen(newname); - if (*(sp - 1) != '/') { - if (sp < newname + newname_len - 4) { - *sp++ = '/'; - *sp = '\0'; - } else { - error = -ENOMEM; - } + pos = ERR_PTR(-ENOMEM); } + if (IS_ERR(pos)) + continue; + name = tomoyo_encode(pos); + break; } - if (error) - tomoyo_warn_oom(__func__); - return error; -} - -/** - * tomoyo_realpath_from_path - Returns realpath(3) of the given pathname but ignores chroot'ed root. - * - * @path: Pointer to "struct path". - * - * Returns the realpath of the given @path on success, NULL otherwise. - * - * These functions use kzalloc(), so the caller must call kfree() - * if these functions didn't return NULL. - */ -char *tomoyo_realpath_from_path(struct path *path) -{ - char *buf = kzalloc(sizeof(struct tomoyo_page_buffer), GFP_NOFS); - - BUILD_BUG_ON(TOMOYO_MAX_PATHNAME_LEN > PATH_MAX); - BUILD_BUG_ON(sizeof(struct tomoyo_page_buffer) - <= TOMOYO_MAX_PATHNAME_LEN - 1); - if (!buf) - return NULL; - if (tomoyo_realpath_from_path2(path, buf, - TOMOYO_MAX_PATHNAME_LEN - 1) == 0) - return buf; kfree(buf); - return NULL; + if (!name) + tomoyo_warn_oom(__func__); + else if (is_dir && *name) { + /* Append trailing '/' if dentry is a directory. */ + char *pos = name + strlen(name) - 1; + if (*pos != '/') + /* + * This is OK because tomoyo_encode() reserves space + * for appending "/". + */ + *++pos = '/'; + } + return name; } /** -- cgit v1.2.3-59-g8ed1b