[SRU][J][PATCH 1/2] UBUNTU: SAUCE: shiftfs: always rely on init_user_ns
Aleksandr Mikhalitsyn
aleksandr.mikhalitsyn at canonical.com
Tue Jan 31 17:40:15 UTC 2023
Please ignore this. New version
https://lists.ubuntu.com/archives/kernel-team/2023-January/136731.html
On Tue, Jan 31, 2023 at 6:31 PM Alexander Mikhalitsyn
<aleksandr.mikhalitsyn at canonical.com> wrote:
>
> From: Andrea Righi <andrea.righi at canonical.com>
>
> With the porting of shiftfs from 5.15 to 5.17 some filesystem-related
> functions are now passing struct user_namespace as argument, however
> shiftfs logic is still relying on the fact that these functions need to
> use the main filesystem namespace.
>
> Make sure to always use init_user_ns to prevent breakage of system
> components that rely on shiftfs.
>
> Without this fix lxd was showing some issues, like failing to create any
> file inside a container when shiftfs was used (e.g., using zfs as
> storage pool).
>
> Signed-off-by: Andrea Righi <andrea.righi at canonical.com>
> ---
> fs/shiftfs.c | 50 ++++++++++++++++++++++++--------------------------
> 1 file changed, 24 insertions(+), 26 deletions(-)
>
> diff --git a/fs/shiftfs.c b/fs/shiftfs.c
> index 76c54bc12018..a21624c529f0 100644
> --- a/fs/shiftfs.c
> +++ b/fs/shiftfs.c
> @@ -308,8 +308,7 @@ static const char *shiftfs_get_link(struct dentry *dentry, struct inode *inode,
> return p;
> }
>
> -static int shiftfs_setxattr(struct user_namespace *ns,
> - struct dentry *dentry, struct inode *inode,
> +static int shiftfs_setxattr(struct dentry *dentry, struct inode *inode,
> const char *name, const void *value,
> size_t size, int flags)
> {
> @@ -318,7 +317,7 @@ static int shiftfs_setxattr(struct user_namespace *ns,
> const struct cred *oldcred;
>
> oldcred = shiftfs_override_creds(dentry->d_sb);
> - err = vfs_setxattr(ns, lowerd, name, value, size, flags);
> + err = vfs_setxattr(&init_user_ns, lowerd, name, value, size, flags);
> revert_creds(oldcred);
>
> shiftfs_copyattr(lowerd->d_inode, inode);
> @@ -363,7 +362,7 @@ static int shiftfs_removexattr(struct user_namespace *ns,
> const struct cred *oldcred;
>
> oldcred = shiftfs_override_creds(dentry->d_sb);
> - err = vfs_removexattr(ns, lowerd, name);
> + err = vfs_removexattr(&init_user_ns, lowerd, name);
> revert_creds(oldcred);
>
> /* update c/mtime */
> @@ -379,8 +378,8 @@ static int shiftfs_xattr_set(const struct xattr_handler *handler,
> int flags)
> {
> if (!value)
> - return shiftfs_removexattr(ns, dentry, name);
> - return shiftfs_setxattr(ns, dentry, inode, name, value, size, flags);
> + return shiftfs_removexattr(&init_user_ns, dentry, name);
> + return shiftfs_setxattr(dentry, inode, name, value, size, flags);
> }
>
> static int shiftfs_inode_test(struct inode *inode, void *data)
> @@ -394,8 +393,7 @@ static int shiftfs_inode_set(struct inode *inode, void *data)
> return 0;
> }
>
> -static int shiftfs_create_object(struct user_namespace *ns,
> - struct inode *diri, struct dentry *dentry,
> +static int shiftfs_create_object(struct inode *diri, struct dentry *dentry,
> umode_t mode, const char *symlink,
> struct dentry *hardlink, bool excl)
> {
> @@ -457,7 +455,7 @@ static int shiftfs_create_object(struct user_namespace *ns,
> inode->i_state |= I_CREATING;
> spin_unlock(&inode->i_lock);
>
> - inode_init_owner(ns, inode, diri, mode);
> + inode_init_owner(&init_user_ns, inode, diri, mode);
> modei = inode->i_mode;
> }
>
> @@ -468,22 +466,22 @@ static int shiftfs_create_object(struct user_namespace *ns,
>
> if (hardlink) {
> lowerd_link = hardlink->d_fsdata;
> - err = vfs_link(lowerd_link, ns, loweri_dir, lowerd_new, NULL);
> + err = vfs_link(lowerd_link, &init_user_ns, loweri_dir, lowerd_new, NULL);
> } else {
> switch (modei & S_IFMT) {
> case S_IFDIR:
> - err = vfs_mkdir(ns, loweri_dir, lowerd_new, modei);
> + err = vfs_mkdir(&init_user_ns, loweri_dir, lowerd_new, modei);
> break;
> case S_IFREG:
> - err = vfs_create(ns, loweri_dir, lowerd_new, modei, excl);
> + err = vfs_create(&init_user_ns, loweri_dir, lowerd_new, modei, excl);
> break;
> case S_IFLNK:
> - err = vfs_symlink(ns, loweri_dir, lowerd_new, symlink);
> + err = vfs_symlink(&init_user_ns, loweri_dir, lowerd_new, symlink);
> break;
> case S_IFSOCK:
> /* fall through */
> case S_IFIFO:
> - err = vfs_mknod(ns, loweri_dir, lowerd_new, modei, 0);
> + err = vfs_mknod(&init_user_ns, loweri_dir, lowerd_new, modei, 0);
> break;
> default:
> err = -EINVAL;
> @@ -545,7 +543,7 @@ static int shiftfs_create(struct user_namespace *ns,
> {
> mode |= S_IFREG;
>
> - return shiftfs_create_object(ns, dir, dentry, mode, NULL, NULL, excl);
> + return shiftfs_create_object(dir, dentry, mode, NULL, NULL, excl);
> }
>
> static int shiftfs_mkdir(struct user_namespace *ns, struct inode *dir, struct dentry *dentry,
> @@ -553,13 +551,13 @@ static int shiftfs_mkdir(struct user_namespace *ns, struct inode *dir, struct de
> {
> mode |= S_IFDIR;
>
> - return shiftfs_create_object(ns, dir, dentry, mode, NULL, NULL, false);
> + return shiftfs_create_object(dir, dentry, mode, NULL, NULL, false);
> }
>
> static int shiftfs_link(struct dentry *hardlink, struct inode *dir,
> struct dentry *dentry)
> {
> - return shiftfs_create_object(&init_user_ns, dir, dentry, 0, NULL, hardlink, false);
> + return shiftfs_create_object(dir, dentry, 0, NULL, hardlink, false);
> }
>
> static int shiftfs_mknod(struct user_namespace *ns,
> @@ -569,13 +567,13 @@ static int shiftfs_mknod(struct user_namespace *ns,
> if (!S_ISFIFO(mode) && !S_ISSOCK(mode))
> return -EPERM;
>
> - return shiftfs_create_object(ns, dir, dentry, mode, NULL, NULL, false);
> + return shiftfs_create_object(dir, dentry, mode, NULL, NULL, false);
> }
>
> static int shiftfs_symlink(struct user_namespace *ns, struct inode *dir, struct dentry *dentry,
> const char *symlink)
> {
> - return shiftfs_create_object(ns, dir, dentry, S_IFLNK, symlink, NULL, false);
> + return shiftfs_create_object(dir, dentry, S_IFLNK, symlink, NULL, false);
> }
>
> static int shiftfs_rm(struct inode *dir, struct dentry *dentry, bool rmdir)
> @@ -716,12 +714,12 @@ static int shiftfs_permission(struct user_namespace *ns, struct inode *inode, in
> return -ECHILD;
> }
>
> - err = generic_permission(ns, inode, mask);
> + err = generic_permission(&init_user_ns, inode, mask);
> if (err)
> return err;
>
> oldcred = shiftfs_override_creds(inode->i_sb);
> - err = inode_permission(ns, loweri, mask);
> + err = inode_permission(&init_user_ns, loweri, mask);
> revert_creds(oldcred);
>
> return err;
> @@ -760,7 +758,7 @@ static int shiftfs_tmpfile(struct user_namespace *ns,
> return -EOPNOTSUPP;
>
> oldcred = shiftfs_override_creds(dir->i_sb);
> - err = loweri->i_op->tmpfile(ns, loweri, lowerd, mode);
> + err = loweri->i_op->tmpfile(&init_user_ns, loweri, lowerd, mode);
> revert_creds(oldcred);
>
> return err;
> @@ -776,7 +774,7 @@ static int shiftfs_setattr(struct user_namespace *ns, struct dentry *dentry, str
> struct shiftfs_super_info *sbinfo = sb->s_fs_info;
> int err;
>
> - err = setattr_prepare(ns, dentry, attr);
> + err = setattr_prepare(&init_user_ns, dentry, attr);
> if (err)
> return err;
>
> @@ -793,7 +791,7 @@ static int shiftfs_setattr(struct user_namespace *ns, struct dentry *dentry, str
>
> inode_lock(loweri);
> oldcred = shiftfs_override_creds(dentry->d_sb);
> - err = notify_change(ns, lowerd, &newattr, NULL);
> + err = notify_change(&init_user_ns, lowerd, &newattr, NULL);
> revert_creds(oldcred);
> inode_unlock(loweri);
>
> @@ -980,10 +978,10 @@ shiftfs_posix_acl_xattr_set(const struct xattr_handler *handler,
> shift_acl_xattr_ids(inode->i_sb->s_user_ns,
> loweri->i_sb->s_user_ns,
> (void *)value, size);
> - err = shiftfs_setxattr(ns, dentry, inode, handler->name, value,
> + err = shiftfs_setxattr(dentry, inode, handler->name, value,
> size, flags);
> } else {
> - err = shiftfs_removexattr(ns, dentry, handler->name);
> + err = shiftfs_removexattr(&init_user_ns, dentry, handler->name);
> }
>
> if (!err)
> --
> 2.34.1
>
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