mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-26 12:26:11 +00:00
fuse update for 6.0
-----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQSQHSd0lITzzeNWNm3h3BK/laaZPAUCYvD4IQAKCRDh3BK/laaZ PDHHAP93H+2E9c6biGd5pEaL2ABChRY+wsQURzD+SZ6AL3JaUQD+KHxA4q0MJvws L6CWcf2XptUDCLe3P6sgSTvv5Gk1OAM= =FoXF -----END PGP SIGNATURE----- Merge tag 'fuse-update-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse updates from Miklos Szeredi: - Fix an issue with reusing the bdi in case of block based filesystems - Allow root (in init namespace) to access fuse filesystems in user namespaces if expicitly enabled with a module param - Misc fixes * tag 'fuse-update-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: retire block-device-based superblock on force unmount vfs: function to prevent re-use of block-device-based superblocks virtio_fs: Modify format for virtio_fs_direct_access virtiofs: delete unused parameter for virtio_fs_cleanup_vqs fuse: Add module param for CAP_SYS_ADMIN access bypassing allow_other fuse: Remove the control interface for virtio-fs fuse: ioctl: translate ENOSYS fuse: limit nsec fuse: avoid unnecessary spinlock bump fuse: fix deadlock between atomic O_TRUNC and page invalidation fuse: write inode in fuse_release()
This commit is contained in:
Linus Torvalds
commit
2bd5d41e0e
10 changed files with 132 additions and 33 deletions
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@ -279,7 +279,7 @@ How are requirements fulfilled?
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the filesystem or not.
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Note that the *ptrace* check is not strictly necessary to
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prevent B/2/i, it is enough to check if mount owner has enough
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prevent C/2/i, it is enough to check if mount owner has enough
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privilege to send signal to the process accessing the
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filesystem, since *SIGSTOP* can be used to get a similar effect.
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@ -288,10 +288,29 @@ I think these limitations are unacceptable?
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If a sysadmin trusts the users enough, or can ensure through other
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measures, that system processes will never enter non-privileged
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mounts, it can relax the last limitation with a 'user_allow_other'
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config option. If this config option is set, the mounting user can
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add the 'allow_other' mount option which disables the check for other
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users' processes.
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mounts, it can relax the last limitation in several ways:
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- With the 'user_allow_other' config option. If this config option is
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set, the mounting user can add the 'allow_other' mount option which
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disables the check for other users' processes.
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User namespaces have an unintuitive interaction with 'allow_other':
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an unprivileged user - normally restricted from mounting with
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'allow_other' - could do so in a user namespace where they're
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privileged. If any process could access such an 'allow_other' mount
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this would give the mounting user the ability to manipulate
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processes in user namespaces where they're unprivileged. For this
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reason 'allow_other' restricts access to users in the same userns
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or a descendant.
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- With the 'allow_sys_admin_access' module option. If this option is
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set, super user's processes have unrestricted access to mounts
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irrespective of allow_other setting or user namespace of the
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mounting user.
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Note that both of these relaxations expose the system to potential
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information leak or *DoS* as described in points B and C/2/i-ii in the
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preceding section.
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Kernel - userspace interface
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============================
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@ -258,7 +258,7 @@ int fuse_ctl_add_conn(struct fuse_conn *fc)
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struct dentry *parent;
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char name[32];
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if (!fuse_control_sb)
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if (!fuse_control_sb || fc->no_control)
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return 0;
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parent = fuse_control_sb->s_root;
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@ -296,7 +296,7 @@ void fuse_ctl_remove_conn(struct fuse_conn *fc)
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{
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int i;
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if (!fuse_control_sb)
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if (!fuse_control_sb || fc->no_control)
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return;
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for (i = fc->ctl_ndents - 1; i >= 0; i--) {
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@ -138,9 +138,9 @@ static struct fuse_dax_mapping *alloc_dax_mapping(struct fuse_conn_dax *fcd)
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WARN_ON(fcd->nr_free_ranges <= 0);
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fcd->nr_free_ranges--;
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}
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__kick_dmap_free_worker(fcd, 0);
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spin_unlock(&fcd->lock);
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kick_dmap_free_worker(fcd, 0);
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return dmap;
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}
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@ -11,6 +11,7 @@
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#include <linux/pagemap.h>
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#include <linux/file.h>
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#include <linux/fs_context.h>
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#include <linux/moduleparam.h>
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#include <linux/sched.h>
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#include <linux/namei.h>
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#include <linux/slab.h>
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@ -21,6 +22,11 @@
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#include <linux/types.h>
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#include <linux/kernel.h>
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static bool __read_mostly allow_sys_admin_access;
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module_param(allow_sys_admin_access, bool, 0644);
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MODULE_PARM_DESC(allow_sys_admin_access,
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"Allow users with CAP_SYS_ADMIN in initial userns to bypass allow_other access check");
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static void fuse_advise_use_readdirplus(struct inode *dir)
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{
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struct fuse_inode *fi = get_fuse_inode(dir);
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@ -537,6 +543,7 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
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struct fuse_file *ff;
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void *security_ctx = NULL;
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u32 security_ctxlen;
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bool trunc = flags & O_TRUNC;
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/* Userspace expects S_IFREG in create mode */
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BUG_ON((mode & S_IFMT) != S_IFREG);
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@ -561,7 +568,7 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
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inarg.mode = mode;
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inarg.umask = current_umask();
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if (fm->fc->handle_killpriv_v2 && (flags & O_TRUNC) &&
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if (fm->fc->handle_killpriv_v2 && trunc &&
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!(flags & O_EXCL) && !capable(CAP_FSETID)) {
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inarg.open_flags |= FUSE_OPEN_KILL_SUIDGID;
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}
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@ -623,6 +630,10 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
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} else {
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file->private_data = ff;
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fuse_finish_open(inode, file);
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if (fm->fc->atomic_o_trunc && trunc)
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truncate_pagecache(inode, 0);
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else if (!(ff->open_flags & FOPEN_KEEP_CACHE))
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invalidate_inode_pages2(inode->i_mapping);
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}
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return err;
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@ -1224,6 +1235,9 @@ int fuse_allow_current_process(struct fuse_conn *fc)
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{
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const struct cred *cred;
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if (allow_sys_admin_access && capable(CAP_SYS_ADMIN))
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return 1;
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if (fc->allow_other)
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return current_in_userns(fc->user_ns);
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@ -210,13 +210,9 @@ void fuse_finish_open(struct inode *inode, struct file *file)
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fi->attr_version = atomic64_inc_return(&fc->attr_version);
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i_size_write(inode, 0);
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spin_unlock(&fi->lock);
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truncate_pagecache(inode, 0);
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file_update_time(file);
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fuse_invalidate_attr_mask(inode, FUSE_STATX_MODSIZE);
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} else if (!(ff->open_flags & FOPEN_KEEP_CACHE)) {
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invalidate_inode_pages2(inode->i_mapping);
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}
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if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache)
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fuse_link_write_file(file);
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}
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@ -239,30 +235,38 @@ int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
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if (err)
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return err;
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if (is_wb_truncate || dax_truncate) {
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if (is_wb_truncate || dax_truncate)
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inode_lock(inode);
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fuse_set_nowrite(inode);
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}
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if (dax_truncate) {
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filemap_invalidate_lock(inode->i_mapping);
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err = fuse_dax_break_layouts(inode, 0, 0);
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if (err)
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goto out;
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goto out_inode_unlock;
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}
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if (is_wb_truncate || dax_truncate)
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fuse_set_nowrite(inode);
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err = fuse_do_open(fm, get_node_id(inode), file, isdir);
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if (!err)
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fuse_finish_open(inode, file);
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out:
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if (is_wb_truncate || dax_truncate)
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fuse_release_nowrite(inode);
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if (!err) {
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struct fuse_file *ff = file->private_data;
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if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC))
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truncate_pagecache(inode, 0);
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else if (!(ff->open_flags & FOPEN_KEEP_CACHE))
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invalidate_inode_pages2(inode->i_mapping);
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}
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if (dax_truncate)
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filemap_invalidate_unlock(inode->i_mapping);
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if (is_wb_truncate | dax_truncate) {
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fuse_release_nowrite(inode);
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out_inode_unlock:
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if (is_wb_truncate || dax_truncate)
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inode_unlock(inode);
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}
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return err;
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}
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@ -338,6 +342,15 @@ static int fuse_open(struct inode *inode, struct file *file)
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static int fuse_release(struct inode *inode, struct file *file)
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{
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struct fuse_conn *fc = get_fuse_conn(inode);
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/*
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* Dirty pages might remain despite write_inode_now() call from
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* fuse_flush() due to writes racing with the close.
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*/
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if (fc->writeback_cache)
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write_inode_now(inode, 1);
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fuse_release_common(file, false);
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/* return value is ignored by VFS */
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@ -180,6 +180,12 @@ void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
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inode->i_uid = make_kuid(fc->user_ns, attr->uid);
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inode->i_gid = make_kgid(fc->user_ns, attr->gid);
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inode->i_blocks = attr->blocks;
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/* Sanitize nsecs */
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attr->atimensec = min_t(u32, attr->atimensec, NSEC_PER_SEC - 1);
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attr->mtimensec = min_t(u32, attr->mtimensec, NSEC_PER_SEC - 1);
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attr->ctimensec = min_t(u32, attr->ctimensec, NSEC_PER_SEC - 1);
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inode->i_atime.tv_sec = attr->atime;
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inode->i_atime.tv_nsec = attr->atimensec;
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/* mtime from server may be stale due to local buffered write */
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@ -476,8 +482,14 @@ static void fuse_umount_begin(struct super_block *sb)
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{
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struct fuse_conn *fc = get_fuse_conn_super(sb);
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if (!fc->no_force_umount)
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fuse_abort_conn(fc);
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if (fc->no_force_umount)
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return;
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fuse_abort_conn(fc);
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// Only retire block-device-based superblocks.
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if (sb->s_bdev != NULL)
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retire_super(sb);
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}
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static void fuse_send_destroy(struct fuse_mount *fm)
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@ -9,6 +9,17 @@
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#include <linux/compat.h>
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#include <linux/fileattr.h>
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static ssize_t fuse_send_ioctl(struct fuse_mount *fm, struct fuse_args *args)
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{
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ssize_t ret = fuse_simple_request(fm, args);
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/* Translate ENOSYS, which shouldn't be returned from fs */
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if (ret == -ENOSYS)
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ret = -ENOTTY;
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return ret;
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}
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/*
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* CUSE servers compiled on 32bit broke on 64bit kernels because the
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* ABI was defined to be 'struct iovec' which is different on 32bit
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@ -259,7 +270,7 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
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ap.args.out_pages = true;
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ap.args.out_argvar = true;
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transferred = fuse_simple_request(fm, &ap.args);
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transferred = fuse_send_ioctl(fm, &ap.args);
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err = transferred;
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if (transferred < 0)
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goto out;
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@ -393,7 +404,7 @@ static int fuse_priv_ioctl(struct inode *inode, struct fuse_file *ff,
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args.out_args[1].size = inarg.out_size;
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args.out_args[1].value = ptr;
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err = fuse_simple_request(fm, &args);
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err = fuse_send_ioctl(fm, &args);
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if (!err) {
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if (outarg.result < 0)
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err = outarg.result;
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|
|
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@ -741,8 +741,7 @@ static int virtio_fs_setup_vqs(struct virtio_device *vdev,
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}
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/* Free virtqueues (device must already be reset) */
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static void virtio_fs_cleanup_vqs(struct virtio_device *vdev,
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struct virtio_fs *fs)
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static void virtio_fs_cleanup_vqs(struct virtio_device *vdev)
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{
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vdev->config->del_vqs(vdev);
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}
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@ -757,7 +756,7 @@ static long virtio_fs_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
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{
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struct virtio_fs *fs = dax_get_private(dax_dev);
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phys_addr_t offset = PFN_PHYS(pgoff);
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size_t max_nr_pages = fs->window_len/PAGE_SIZE - pgoff;
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size_t max_nr_pages = fs->window_len / PAGE_SIZE - pgoff;
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if (kaddr)
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*kaddr = fs->window_kaddr + offset;
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||||
|
|
@ -895,7 +894,7 @@ static int virtio_fs_probe(struct virtio_device *vdev)
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|||
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||||
out_vqs:
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||||
virtio_reset_device(vdev);
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virtio_fs_cleanup_vqs(vdev, fs);
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||||
virtio_fs_cleanup_vqs(vdev);
|
||||
kfree(fs->vqs);
|
||||
|
||||
out:
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||||
|
|
@ -927,7 +926,7 @@ static void virtio_fs_remove(struct virtio_device *vdev)
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virtio_fs_stop_all_queues(fs);
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||||
virtio_fs_drain_all_queues_locked(fs);
|
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virtio_reset_device(vdev);
|
||||
virtio_fs_cleanup_vqs(vdev, fs);
|
||||
virtio_fs_cleanup_vqs(vdev);
|
||||
|
||||
vdev->priv = NULL;
|
||||
/* Put device reference on virtio_fs object */
|
||||
|
|
|
|||
33
fs/super.c
33
fs/super.c
|
|
@ -422,6 +422,35 @@ bool trylock_super(struct super_block *sb)
|
|||
return false;
|
||||
}
|
||||
|
||||
/**
|
||||
* retire_super - prevents superblock from being reused
|
||||
* @sb: superblock to retire
|
||||
*
|
||||
* The function marks superblock to be ignored in superblock test, which
|
||||
* prevents it from being reused for any new mounts. If the superblock has
|
||||
* a private bdi, it also unregisters it, but doesn't reduce the refcount
|
||||
* of the superblock to prevent potential races. The refcount is reduced
|
||||
* by generic_shutdown_super(). The function can not be called
|
||||
* concurrently with generic_shutdown_super(). It is safe to call the
|
||||
* function multiple times, subsequent calls have no effect.
|
||||
*
|
||||
* The marker will affect the re-use only for block-device-based
|
||||
* superblocks. Other superblocks will still get marked if this function
|
||||
* is used, but that will not affect their reusability.
|
||||
*/
|
||||
void retire_super(struct super_block *sb)
|
||||
{
|
||||
WARN_ON(!sb->s_bdev);
|
||||
down_write(&sb->s_umount);
|
||||
if (sb->s_iflags & SB_I_PERSB_BDI) {
|
||||
bdi_unregister(sb->s_bdi);
|
||||
sb->s_iflags &= ~SB_I_PERSB_BDI;
|
||||
}
|
||||
sb->s_iflags |= SB_I_RETIRED;
|
||||
up_write(&sb->s_umount);
|
||||
}
|
||||
EXPORT_SYMBOL(retire_super);
|
||||
|
||||
/**
|
||||
* generic_shutdown_super - common helper for ->kill_sb()
|
||||
* @sb: superblock to kill
|
||||
|
|
@ -1216,7 +1245,7 @@ static int set_bdev_super_fc(struct super_block *s, struct fs_context *fc)
|
|||
|
||||
static int test_bdev_super_fc(struct super_block *s, struct fs_context *fc)
|
||||
{
|
||||
return s->s_bdev == fc->sget_key;
|
||||
return !(s->s_iflags & SB_I_RETIRED) && s->s_bdev == fc->sget_key;
|
||||
}
|
||||
|
||||
/**
|
||||
|
|
@ -1309,7 +1338,7 @@ EXPORT_SYMBOL(get_tree_bdev);
|
|||
|
||||
static int test_bdev_super(struct super_block *s, void *data)
|
||||
{
|
||||
return (void *)s->s_bdev == data;
|
||||
return !(s->s_iflags & SB_I_RETIRED) && (void *)s->s_bdev == data;
|
||||
}
|
||||
|
||||
struct dentry *mount_bdev(struct file_system_type *fs_type,
|
||||
|
|
|
|||
|
|
@ -1433,6 +1433,7 @@ extern int send_sigurg(struct fown_struct *fown);
|
|||
#define SB_I_SKIP_SYNC 0x00000100 /* Skip superblock at global sync */
|
||||
#define SB_I_PERSB_BDI 0x00000200 /* has a per-sb bdi */
|
||||
#define SB_I_TS_EXPIRY_WARNED 0x00000400 /* warned about timestamp range expiry */
|
||||
#define SB_I_RETIRED 0x00000800 /* superblock shouldn't be reused */
|
||||
|
||||
/* Possible states of 'frozen' field */
|
||||
enum {
|
||||
|
|
@ -2565,6 +2566,7 @@ extern struct dentry *mount_nodev(struct file_system_type *fs_type,
|
|||
int flags, void *data,
|
||||
int (*fill_super)(struct super_block *, void *, int));
|
||||
extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path);
|
||||
void retire_super(struct super_block *sb);
|
||||
void generic_shutdown_super(struct super_block *sb);
|
||||
void kill_block_super(struct super_block *sb);
|
||||
void kill_anon_super(struct super_block *sb);
|
||||
|
|
|
|||
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