X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Fnamei.c;h=df2d3df4f04950ee5115adb43dc9a4e830b9d3e0;hb=b3e5d37905730dc5ddff717f55ed830caa80ea0e;hp=d34e0f9681c6557d83852cf04646afbf9e670d98;hpb=2433c41789d6aa6797ca747707b7764e88e4fb6d;p=linux-2.6-omap-h63xx.git diff --git a/fs/namei.c b/fs/namei.c index d34e0f9681c..df2d3df4f04 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -186,7 +186,7 @@ int generic_permission(struct inode *inode, int mask, mask &= MAY_READ | MAY_WRITE | MAY_EXEC; - if (current->fsuid == inode->i_uid) + if (current_fsuid() == inode->i_uid) mode >>= 6; else { if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) { @@ -226,6 +226,16 @@ int generic_permission(struct inode *inode, int mask, return -EACCES; } +/** + * inode_permission - check for access rights to a given inode + * @inode: inode to check permission on + * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) + * + * Used to check for read/write/execute permissions on an inode. + * We use "fsuid" for this, letting us set arbitrary permissions + * for filesystem access without changing the "normal" uids which + * are used for other things. + */ int inode_permission(struct inode *inode, int mask) { int retval; @@ -247,7 +257,6 @@ int inode_permission(struct inode *inode, int mask) return -EACCES; } - /* Ordinary permission routines do not understand MAY_APPEND. */ if (inode->i_op && inode->i_op->permission) retval = inode->i_op->permission(inode, mask); else @@ -264,21 +273,6 @@ int inode_permission(struct inode *inode, int mask) mask & (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND)); } -/** - * vfs_permission - check for access rights to a given path - * @nd: lookup result that describes the path - * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) - * - * Used to check for read/write/execute permissions on a path. - * We use "fsuid" for this, letting us set arbitrary permissions - * for filesystem access without changing the "normal" uids which - * are used for other things. - */ -int vfs_permission(struct nameidata *nd, int mask) -{ - return inode_permission(nd->path.dentry->d_inode, mask); -} - /** * file_permission - check for additional access rights to a given file * @file: file to check access rights for @@ -289,7 +283,7 @@ int vfs_permission(struct nameidata *nd, int mask) * * Note: * Do not use this function in new code. All access checks should - * be done using vfs_permission(). + * be done using inode_permission(). */ int file_permission(struct file *file, int mask) { @@ -441,7 +435,7 @@ static int exec_permission_lite(struct inode *inode) if (inode->i_op && inode->i_op->permission) return -EAGAIN; - if (current->fsuid == inode->i_uid) + if (current_fsuid() == inode->i_uid) mode >>= 6; else if (in_group_p(inode->i_gid)) mode >>= 3; @@ -527,18 +521,6 @@ out_unlock: return result; } -/* SMP-safe */ -static __always_inline void -walk_init_root(const char *name, struct nameidata *nd) -{ - struct fs_struct *fs = current->fs; - - read_lock(&fs->lock); - nd->path = fs->root; - path_get(&fs->root); - read_unlock(&fs->lock); -} - /* * Wrapper to retry pathname resolution whenever the underlying * file system returns an ESTALE. @@ -576,9 +558,16 @@ static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *l goto fail; if (*link == '/') { + struct fs_struct *fs = current->fs; + path_put(&nd->path); - walk_init_root(link, nd); + + read_lock(&fs->lock); + nd->path = fs->root; + path_get(&fs->root); + read_unlock(&fs->lock); } + res = link_path_walk(link, nd); if (nd->depth || res || nd->last_type!=LAST_NORM) return res; @@ -859,7 +848,8 @@ static int __link_path_walk(const char *name, struct nameidata *nd) nd->flags |= LOOKUP_CONTINUE; err = exec_permission_lite(inode); if (err == -EAGAIN) - err = vfs_permission(nd, MAY_EXEC); + err = inode_permission(nd->path.dentry->d_inode, + MAY_EXEC); if (err) break; @@ -1334,11 +1324,13 @@ static int user_path_parent(int dfd, const char __user *path, */ static inline int check_sticky(struct inode *dir, struct inode *inode) { + uid_t fsuid = current_fsuid(); + if (!(dir->i_mode & S_ISVTX)) return 0; - if (inode->i_uid == current->fsuid) + if (inode->i_uid == fsuid) return 0; - if (dir->i_uid == current->fsuid) + if (dir->i_uid == fsuid) return 0; return !capable(CAP_FOWNER); } @@ -1491,9 +1483,9 @@ int vfs_create(struct inode *dir, struct dentry *dentry, int mode, return error; } -int may_open(struct nameidata *nd, int acc_mode, int flag) +int may_open(struct path *path, int acc_mode, int flag) { - struct dentry *dentry = nd->path.dentry; + struct dentry *dentry = path->dentry; struct inode *inode = dentry->d_inode; int error; @@ -1514,13 +1506,13 @@ int may_open(struct nameidata *nd, int acc_mode, int flag) if (S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { flag &= ~O_TRUNC; } else if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) { - if (nd->path.mnt->mnt_flags & MNT_NODEV) + if (path->mnt->mnt_flags & MNT_NODEV) return -EACCES; flag &= ~O_TRUNC; } - error = vfs_permission(nd, acc_mode); + error = inode_permission(inode, acc_mode); if (error) return error; /* @@ -1554,6 +1546,9 @@ int may_open(struct nameidata *nd, int acc_mode, int flag) * Refuse to truncate files with mandatory locks held on them. */ error = locks_verify_locked(inode); + if (!error) + error = security_path_truncate(path, 0, + ATTR_MTIME|ATTR_CTIME|ATTR_OPEN); if (!error) { DQUOT_INIT(inode); @@ -1584,14 +1579,18 @@ static int __open_namei_create(struct nameidata *nd, struct path *path, if (!IS_POSIXACL(dir->d_inode)) mode &= ~current->fs->umask; + error = security_path_mknod(&nd->path, path->dentry, mode, 0); + if (error) + goto out_unlock; error = vfs_create(dir->d_inode, path->dentry, mode, nd); +out_unlock: mutex_unlock(&dir->d_inode->i_mutex); dput(nd->path.dentry); nd->path.dentry = path->dentry; if (error) return error; /* Don't check for write permission, don't truncate */ - return may_open(nd, 0, flag & ~O_TRUNC); + return may_open(&nd->path, 0, flag & ~O_TRUNC); } /* @@ -1777,7 +1776,7 @@ ok: if (error) goto exit; } - error = may_open(&nd, acc_mode, flag); + error = may_open(&nd.path, acc_mode, flag); if (error) { if (will_write) mnt_drop_write(nd.path.mnt); @@ -1997,6 +1996,9 @@ asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode, error = mnt_want_write(nd.path.mnt); if (error) goto out_dput; + error = security_path_mknod(&nd.path, dentry, mode, dev); + if (error) + goto out_drop_write; switch (mode & S_IFMT) { case 0: case S_IFREG: error = vfs_create(nd.path.dentry->d_inode,dentry,mode,&nd); @@ -2009,6 +2011,7 @@ asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode, error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,0); break; } +out_drop_write: mnt_drop_write(nd.path.mnt); out_dput: dput(dentry); @@ -2068,7 +2071,11 @@ asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode) error = mnt_want_write(nd.path.mnt); if (error) goto out_dput; + error = security_path_mkdir(&nd.path, dentry, mode); + if (error) + goto out_drop_write; error = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode); +out_drop_write: mnt_drop_write(nd.path.mnt); out_dput: dput(dentry); @@ -2178,7 +2185,11 @@ static long do_rmdir(int dfd, const char __user *pathname) error = mnt_want_write(nd.path.mnt); if (error) goto exit3; + error = security_path_rmdir(&nd.path, dentry); + if (error) + goto exit4; error = vfs_rmdir(nd.path.dentry->d_inode, dentry); +exit4: mnt_drop_write(nd.path.mnt); exit3: dput(dentry); @@ -2263,7 +2274,11 @@ static long do_unlinkat(int dfd, const char __user *pathname) error = mnt_want_write(nd.path.mnt); if (error) goto exit2; + error = security_path_unlink(&nd.path, dentry); + if (error) + goto exit3; error = vfs_unlink(nd.path.dentry->d_inode, dentry); +exit3: mnt_drop_write(nd.path.mnt); exit2: dput(dentry); @@ -2344,7 +2359,11 @@ asmlinkage long sys_symlinkat(const char __user *oldname, error = mnt_want_write(nd.path.mnt); if (error) goto out_dput; + error = security_path_symlink(&nd.path, dentry, from); + if (error) + goto out_drop_write; error = vfs_symlink(nd.path.dentry->d_inode, dentry, from); +out_drop_write: mnt_drop_write(nd.path.mnt); out_dput: dput(dentry); @@ -2441,7 +2460,11 @@ asmlinkage long sys_linkat(int olddfd, const char __user *oldname, error = mnt_want_write(nd.path.mnt); if (error) goto out_dput; + error = security_path_link(old_path.dentry, &nd.path, new_dentry); + if (error) + goto out_drop_write; error = vfs_link(old_path.dentry, nd.path.dentry->d_inode, new_dentry); +out_drop_write: mnt_drop_write(nd.path.mnt); out_dput: dput(new_dentry); @@ -2677,8 +2700,13 @@ asmlinkage long sys_renameat(int olddfd, const char __user *oldname, error = mnt_want_write(oldnd.path.mnt); if (error) goto exit5; + error = security_path_rename(&oldnd.path, old_dentry, + &newnd.path, new_dentry); + if (error) + goto exit6; error = vfs_rename(old_dir->d_inode, old_dentry, new_dir->d_inode, new_dentry); +exit6: mnt_drop_write(oldnd.path.mnt); exit5: dput(new_dentry); @@ -2748,13 +2776,16 @@ int vfs_follow_link(struct nameidata *nd, const char *link) /* get the link contents into pagecache */ static char *page_getlink(struct dentry * dentry, struct page **ppage) { - struct page * page; + char *kaddr; + struct page *page; struct address_space *mapping = dentry->d_inode->i_mapping; page = read_mapping_page(mapping, 0, NULL); if (IS_ERR(page)) return (char*)page; *ppage = page; - return kmap(page); + kaddr = kmap(page); + nd_terminate_link(kaddr, dentry->d_inode->i_size, PAGE_SIZE - 1); + return kaddr; } int page_readlink(struct dentry *dentry, char __user *buffer, int buflen) @@ -2786,18 +2817,23 @@ void page_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) } } -int __page_symlink(struct inode *inode, const char *symname, int len, - gfp_t gfp_mask) +/* + * The nofs argument instructs pagecache_write_begin to pass AOP_FLAG_NOFS + */ +int __page_symlink(struct inode *inode, const char *symname, int len, int nofs) { struct address_space *mapping = inode->i_mapping; struct page *page; void *fsdata; int err; char *kaddr; + unsigned int flags = AOP_FLAG_UNINTERRUPTIBLE; + if (nofs) + flags |= AOP_FLAG_NOFS; retry: err = pagecache_write_begin(NULL, mapping, 0, len-1, - AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata); + flags, &page, &fsdata); if (err) goto fail; @@ -2821,7 +2857,7 @@ fail: int page_symlink(struct inode *inode, const char *symname, int len) { return __page_symlink(inode, symname, len, - mapping_gfp_mask(inode->i_mapping)); + !(mapping_gfp_mask(inode->i_mapping) & __GFP_FS)); } const struct inode_operations page_symlink_inode_operations = { @@ -2847,7 +2883,6 @@ EXPORT_SYMBOL(path_lookup); EXPORT_SYMBOL(kern_path); EXPORT_SYMBOL(vfs_path_lookup); EXPORT_SYMBOL(inode_permission); -EXPORT_SYMBOL(vfs_permission); EXPORT_SYMBOL(file_permission); EXPORT_SYMBOL(unlock_rename); EXPORT_SYMBOL(vfs_create); @@ -2863,3 +2898,10 @@ EXPORT_SYMBOL(vfs_symlink); EXPORT_SYMBOL(vfs_unlink); EXPORT_SYMBOL(dentry_unhash); EXPORT_SYMBOL(generic_readlink); + +/* to be mentioned only in INIT_TASK */ +struct fs_struct init_fs = { + .count = ATOMIC_INIT(1), + .lock = __RW_LOCK_UNLOCKED(init_fs.lock), + .umask = 0022, +};