From cb3ae6d25a5471be62bfe6ac1fccc0e91edeaba0 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Sat, 1 Oct 2016 07:32:32 +0200 Subject: fuse: listxattr: verify xattr list Make sure userspace filesystem is returning a well formed list of xattr names (zero or more nonzero length, null terminated strings). [Michael Theall: only verify in the nonzero size case] Signed-off-by: Miklos Szeredi Cc: diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index c47b778..b87c9bc 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -1801,6 +1801,23 @@ static ssize_t fuse_getxattr(struct dentry *entry, struct inode *inode, return ret; } +static int fuse_verify_xattr_list(char *list, size_t size) +{ + size_t origsize = size; + + while (size) { + size_t thislen = strnlen(list, size); + + if (!thislen || thislen == size) + return -EIO; + + size -= thislen + 1; + list += thislen + 1; + } + + return origsize; +} + static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size) { struct inode *inode = d_inode(entry); @@ -1836,6 +1853,8 @@ static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size) ret = fuse_simple_request(fc, &args); if (!ret && !size) ret = outarg.size; + if (ret > 0 && size) + ret = fuse_verify_xattr_list(list, ret); if (ret == -ENOSYS) { fc->no_listxattr = 1; ret = -EOPNOTSUPP; -- cgit v0.10.2 From 703c73629f93464ce210f5ad92d0c1fb95bfbadf Mon Sep 17 00:00:00 2001 From: Seth Forshee Date: Mon, 29 Aug 2016 08:46:36 -0500 Subject: fuse: Use generic xattr ops In preparation for posix acl support, rework fuse to use xattr handlers and the generic setxattr/getxattr/listxattr callbacks. Split the xattr code out into it's own file, and promote symbols to module-global scope as needed. Functionally these changes have no impact, as fuse still uses a single handler for all xattrs which uses the old callbacks. Signed-off-by: Seth Forshee Signed-off-by: Miklos Szeredi diff --git a/fs/fuse/Makefile b/fs/fuse/Makefile index e95eeb4..448aa27 100644 --- a/fs/fuse/Makefile +++ b/fs/fuse/Makefile @@ -5,4 +5,4 @@ obj-$(CONFIG_FUSE_FS) += fuse.o obj-$(CONFIG_CUSE) += cuse.o -fuse-objs := dev.o dir.o file.o inode.o control.o +fuse-objs := dev.o dir.o file.o inode.o control.o xattr.o diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index b87c9bc..7490db1 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -13,6 +13,7 @@ #include #include #include +#include static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx) { @@ -634,7 +635,7 @@ static int fuse_symlink(struct inode *dir, struct dentry *entry, return create_new_entry(fc, &args, dir, entry, S_IFLNK); } -static inline void fuse_update_ctime(struct inode *inode) +void fuse_update_ctime(struct inode *inode) { if (!IS_NOCMTIME(inode)) { inode->i_ctime = current_fs_time(inode->i_sb); @@ -1724,171 +1725,6 @@ static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry, return fuse_update_attributes(inode, stat, NULL, NULL); } -static int fuse_setxattr(struct dentry *unused, struct inode *inode, - const char *name, const void *value, - size_t size, int flags) -{ - struct fuse_conn *fc = get_fuse_conn(inode); - FUSE_ARGS(args); - struct fuse_setxattr_in inarg; - int err; - - if (fc->no_setxattr) - return -EOPNOTSUPP; - - memset(&inarg, 0, sizeof(inarg)); - inarg.size = size; - inarg.flags = flags; - args.in.h.opcode = FUSE_SETXATTR; - args.in.h.nodeid = get_node_id(inode); - args.in.numargs = 3; - args.in.args[0].size = sizeof(inarg); - args.in.args[0].value = &inarg; - args.in.args[1].size = strlen(name) + 1; - args.in.args[1].value = name; - args.in.args[2].size = size; - args.in.args[2].value = value; - err = fuse_simple_request(fc, &args); - if (err == -ENOSYS) { - fc->no_setxattr = 1; - err = -EOPNOTSUPP; - } - if (!err) { - fuse_invalidate_attr(inode); - fuse_update_ctime(inode); - } - return err; -} - -static ssize_t fuse_getxattr(struct dentry *entry, struct inode *inode, - const char *name, void *value, size_t size) -{ - struct fuse_conn *fc = get_fuse_conn(inode); - FUSE_ARGS(args); - struct fuse_getxattr_in inarg; - struct fuse_getxattr_out outarg; - ssize_t ret; - - if (fc->no_getxattr) - return -EOPNOTSUPP; - - memset(&inarg, 0, sizeof(inarg)); - inarg.size = size; - args.in.h.opcode = FUSE_GETXATTR; - args.in.h.nodeid = get_node_id(inode); - args.in.numargs = 2; - args.in.args[0].size = sizeof(inarg); - args.in.args[0].value = &inarg; - args.in.args[1].size = strlen(name) + 1; - args.in.args[1].value = name; - /* This is really two different operations rolled into one */ - args.out.numargs = 1; - if (size) { - args.out.argvar = 1; - args.out.args[0].size = size; - args.out.args[0].value = value; - } else { - args.out.args[0].size = sizeof(outarg); - args.out.args[0].value = &outarg; - } - ret = fuse_simple_request(fc, &args); - if (!ret && !size) - ret = outarg.size; - if (ret == -ENOSYS) { - fc->no_getxattr = 1; - ret = -EOPNOTSUPP; - } - return ret; -} - -static int fuse_verify_xattr_list(char *list, size_t size) -{ - size_t origsize = size; - - while (size) { - size_t thislen = strnlen(list, size); - - if (!thislen || thislen == size) - return -EIO; - - size -= thislen + 1; - list += thislen + 1; - } - - return origsize; -} - -static ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size) -{ - struct inode *inode = d_inode(entry); - struct fuse_conn *fc = get_fuse_conn(inode); - FUSE_ARGS(args); - struct fuse_getxattr_in inarg; - struct fuse_getxattr_out outarg; - ssize_t ret; - - if (!fuse_allow_current_process(fc)) - return -EACCES; - - if (fc->no_listxattr) - return -EOPNOTSUPP; - - memset(&inarg, 0, sizeof(inarg)); - inarg.size = size; - args.in.h.opcode = FUSE_LISTXATTR; - args.in.h.nodeid = get_node_id(inode); - args.in.numargs = 1; - args.in.args[0].size = sizeof(inarg); - args.in.args[0].value = &inarg; - /* This is really two different operations rolled into one */ - args.out.numargs = 1; - if (size) { - args.out.argvar = 1; - args.out.args[0].size = size; - args.out.args[0].value = list; - } else { - args.out.args[0].size = sizeof(outarg); - args.out.args[0].value = &outarg; - } - ret = fuse_simple_request(fc, &args); - if (!ret && !size) - ret = outarg.size; - if (ret > 0 && size) - ret = fuse_verify_xattr_list(list, ret); - if (ret == -ENOSYS) { - fc->no_listxattr = 1; - ret = -EOPNOTSUPP; - } - return ret; -} - -static int fuse_removexattr(struct dentry *entry, const char *name) -{ - struct inode *inode = d_inode(entry); - struct fuse_conn *fc = get_fuse_conn(inode); - FUSE_ARGS(args); - int err; - - if (fc->no_removexattr) - return -EOPNOTSUPP; - - args.in.h.opcode = FUSE_REMOVEXATTR; - args.in.h.nodeid = get_node_id(inode); - args.in.numargs = 1; - args.in.args[0].size = strlen(name) + 1; - args.in.args[0].value = name; - err = fuse_simple_request(fc, &args); - if (err == -ENOSYS) { - fc->no_removexattr = 1; - err = -EOPNOTSUPP; - } - if (!err) { - fuse_invalidate_attr(inode); - fuse_update_ctime(inode); - } - return err; -} - static const struct inode_operations fuse_dir_inode_operations = { .lookup = fuse_lookup, .mkdir = fuse_mkdir, @@ -1903,10 +1739,10 @@ static const struct inode_operations fuse_dir_inode_operations = { .mknod = fuse_mknod, .permission = fuse_permission, .getattr = fuse_getattr, - .setxattr = fuse_setxattr, - .getxattr = fuse_getxattr, + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, .listxattr = fuse_listxattr, - .removexattr = fuse_removexattr, + .removexattr = generic_removexattr, }; static const struct file_operations fuse_dir_operations = { @@ -1924,10 +1760,10 @@ static const struct inode_operations fuse_common_inode_operations = { .setattr = fuse_setattr, .permission = fuse_permission, .getattr = fuse_getattr, - .setxattr = fuse_setxattr, - .getxattr = fuse_getxattr, + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, .listxattr = fuse_listxattr, - .removexattr = fuse_removexattr, + .removexattr = generic_removexattr, }; static const struct inode_operations fuse_symlink_inode_operations = { @@ -1935,10 +1771,10 @@ static const struct inode_operations fuse_symlink_inode_operations = { .get_link = fuse_get_link, .readlink = generic_readlink, .getattr = fuse_getattr, - .setxattr = fuse_setxattr, - .getxattr = fuse_getxattr, + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, .listxattr = fuse_listxattr, - .removexattr = fuse_removexattr, + .removexattr = generic_removexattr, }; void fuse_init_common(struct inode *inode) diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index d98d8cc..6db54d0 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -902,6 +902,8 @@ int fuse_allow_current_process(struct fuse_conn *fc); u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id); +void fuse_update_ctime(struct inode *inode); + int fuse_update_attributes(struct inode *inode, struct kstat *stat, struct file *file, bool *refreshed); @@ -966,4 +968,7 @@ void fuse_set_initialized(struct fuse_conn *fc); void fuse_unlock_inode(struct inode *inode); void fuse_lock_inode(struct inode *inode); +ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size); +extern const struct xattr_handler *fuse_xattr_handlers[]; + #endif /* _FS_FUSE_I_H */ diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 4e05b51..1e535f3 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1071,6 +1071,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) } sb->s_magic = FUSE_SUPER_MAGIC; sb->s_op = &fuse_super_operations; + sb->s_xattr = fuse_xattr_handlers; sb->s_maxbytes = MAX_LFS_FILESIZE; sb->s_time_gran = 1; sb->s_export_op = &fuse_export_operations; diff --git a/fs/fuse/xattr.c b/fs/fuse/xattr.c new file mode 100644 index 0000000..e22980f --- /dev/null +++ b/fs/fuse/xattr.c @@ -0,0 +1,203 @@ +/* + * FUSE: Filesystem in Userspace + * Copyright (C) 2001-2016 Miklos Szeredi + * + * This program can be distributed under the terms of the GNU GPL. + * See the file COPYING. + */ + +#include "fuse_i.h" + +#include + +static int fuse_setxattr(struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + struct fuse_conn *fc = get_fuse_conn(inode); + FUSE_ARGS(args); + struct fuse_setxattr_in inarg; + int err; + + if (fc->no_setxattr) + return -EOPNOTSUPP; + + memset(&inarg, 0, sizeof(inarg)); + inarg.size = size; + inarg.flags = flags; + args.in.h.opcode = FUSE_SETXATTR; + args.in.h.nodeid = get_node_id(inode); + args.in.numargs = 3; + args.in.args[0].size = sizeof(inarg); + args.in.args[0].value = &inarg; + args.in.args[1].size = strlen(name) + 1; + args.in.args[1].value = name; + args.in.args[2].size = size; + args.in.args[2].value = value; + err = fuse_simple_request(fc, &args); + if (err == -ENOSYS) { + fc->no_setxattr = 1; + err = -EOPNOTSUPP; + } + if (!err) { + fuse_invalidate_attr(inode); + fuse_update_ctime(inode); + } + return err; +} + +static ssize_t fuse_getxattr(struct inode *inode, const char *name, + void *value, size_t size) +{ + struct fuse_conn *fc = get_fuse_conn(inode); + FUSE_ARGS(args); + struct fuse_getxattr_in inarg; + struct fuse_getxattr_out outarg; + ssize_t ret; + + if (fc->no_getxattr) + return -EOPNOTSUPP; + + memset(&inarg, 0, sizeof(inarg)); + inarg.size = size; + args.in.h.opcode = FUSE_GETXATTR; + args.in.h.nodeid = get_node_id(inode); + args.in.numargs = 2; + args.in.args[0].size = sizeof(inarg); + args.in.args[0].value = &inarg; + args.in.args[1].size = strlen(name) + 1; + args.in.args[1].value = name; + /* This is really two different operations rolled into one */ + args.out.numargs = 1; + if (size) { + args.out.argvar = 1; + args.out.args[0].size = size; + args.out.args[0].value = value; + } else { + args.out.args[0].size = sizeof(outarg); + args.out.args[0].value = &outarg; + } + ret = fuse_simple_request(fc, &args); + if (!ret && !size) + ret = outarg.size; + if (ret == -ENOSYS) { + fc->no_getxattr = 1; + ret = -EOPNOTSUPP; + } + return ret; +} + +static int fuse_verify_xattr_list(char *list, size_t size) +{ + size_t origsize = size; + + while (size) { + size_t thislen = strnlen(list, size); + + if (!thislen || thislen == size) + return -EIO; + + size -= thislen + 1; + list += thislen + 1; + } + + return origsize; +} + +ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size) +{ + struct inode *inode = d_inode(entry); + struct fuse_conn *fc = get_fuse_conn(inode); + FUSE_ARGS(args); + struct fuse_getxattr_in inarg; + struct fuse_getxattr_out outarg; + ssize_t ret; + + if (!fuse_allow_current_process(fc)) + return -EACCES; + + if (fc->no_listxattr) + return -EOPNOTSUPP; + + memset(&inarg, 0, sizeof(inarg)); + inarg.size = size; + args.in.h.opcode = FUSE_LISTXATTR; + args.in.h.nodeid = get_node_id(inode); + args.in.numargs = 1; + args.in.args[0].size = sizeof(inarg); + args.in.args[0].value = &inarg; + /* This is really two different operations rolled into one */ + args.out.numargs = 1; + if (size) { + args.out.argvar = 1; + args.out.args[0].size = size; + args.out.args[0].value = list; + } else { + args.out.args[0].size = sizeof(outarg); + args.out.args[0].value = &outarg; + } + ret = fuse_simple_request(fc, &args); + if (!ret && !size) + ret = outarg.size; + if (ret > 0 && size) + ret = fuse_verify_xattr_list(list, ret); + if (ret == -ENOSYS) { + fc->no_listxattr = 1; + ret = -EOPNOTSUPP; + } + return ret; +} + +static int fuse_removexattr(struct inode *inode, const char *name) +{ + struct fuse_conn *fc = get_fuse_conn(inode); + FUSE_ARGS(args); + int err; + + if (fc->no_removexattr) + return -EOPNOTSUPP; + + args.in.h.opcode = FUSE_REMOVEXATTR; + args.in.h.nodeid = get_node_id(inode); + args.in.numargs = 1; + args.in.args[0].size = strlen(name) + 1; + args.in.args[0].value = name; + err = fuse_simple_request(fc, &args); + if (err == -ENOSYS) { + fc->no_removexattr = 1; + err = -EOPNOTSUPP; + } + if (!err) { + fuse_invalidate_attr(inode); + fuse_update_ctime(inode); + } + return err; +} + +static int fuse_xattr_get(const struct xattr_handler *handler, + struct dentry *dentry, struct inode *inode, + const char *name, void *value, size_t size) +{ + return fuse_getxattr(inode, name, value, size); +} + +static int fuse_xattr_set(const struct xattr_handler *handler, + struct dentry *dentry, struct inode *inode, + const char *name, const void *value, size_t size, + int flags) +{ + if (!value) + return fuse_removexattr(inode, name); + + return fuse_setxattr(inode, name, value, size, flags); +} + +static const struct xattr_handler fuse_xattr_handler = { + .prefix = "", + .get = fuse_xattr_get, + .set = fuse_xattr_set, +}; + +const struct xattr_handler *fuse_xattr_handlers[] = { + &fuse_xattr_handler, + NULL +}; -- cgit v0.10.2