diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/overlayfs/dir.c | 4 | ||||
| -rw-r--r-- | fs/overlayfs/namei.c | 74 | ||||
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 6 | ||||
| -rw-r--r-- | fs/overlayfs/readdir.c | 50 | ||||
| -rw-r--r-- | fs/overlayfs/super.c | 6 |
5 files changed, 130 insertions, 10 deletions
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index d0d6292e069a..a072c27e03bc 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -24,7 +24,7 @@ module_param_named(redirect_max, ovl_redirect_max, ushort, 0644); MODULE_PARM_DESC(ovl_redirect_max, "Maximum length of absolute redirect xattr value"); -void ovl_cleanup(struct inode *wdir, struct dentry *wdentry) +int ovl_cleanup(struct inode *wdir, struct dentry *wdentry) { int err; @@ -39,6 +39,8 @@ void ovl_cleanup(struct inode *wdir, struct dentry *wdentry) pr_err("overlayfs: cleanup of '%pd2' failed (%i)\n", wdentry, err); } + + return err; } struct dentry *ovl_lookup_temp(struct dentry *workdir) diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index 3bec4cb39967..4df37e805eb7 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -285,17 +285,17 @@ static int ovl_lookup_layer(struct dentry *base, struct ovl_lookup_data *d, } -static int ovl_check_origin(struct dentry *dentry, struct dentry *upperdentry, +static int ovl_check_origin(struct dentry *upperdentry, + struct path *lowerstack, unsigned int numlower, struct path **stackp, unsigned int *ctrp) { - struct ovl_entry *roe = dentry->d_sb->s_root->d_fsdata; struct vfsmount *mnt; struct dentry *origin = NULL; int i; - for (i = 0; i < roe->numlower; i++) { - mnt = roe->lowerstack[i].mnt; + for (i = 0; i < numlower; i++) { + mnt = lowerstack[i].mnt; origin = ovl_get_origin(upperdentry, mnt); if (IS_ERR(origin)) return PTR_ERR(origin); @@ -307,8 +307,9 @@ static int ovl_check_origin(struct dentry *dentry, struct dentry *upperdentry, if (!origin) return 0; - BUG_ON(*stackp || *ctrp); - *stackp = kmalloc(sizeof(struct path), GFP_TEMPORARY); + BUG_ON(*ctrp); + if (!*stackp) + *stackp = kmalloc(sizeof(struct path), GFP_TEMPORARY); if (!*stackp) { dput(origin); return -ENOMEM; @@ -379,6 +380,63 @@ fail: } /* + * Verify that an index entry name matches the origin file handle stored in + * OVL_XATTR_ORIGIN and that origin file handle can be decoded to lower path. + * Return 0 on match, -ESTALE on mismatch or stale origin, < 0 on error. + */ +int ovl_verify_index(struct dentry *index, struct path *lowerstack, + unsigned int numlower) +{ + struct ovl_fh *fh = NULL; + size_t len; + struct path origin = { }; + struct path *stack = &origin; + unsigned int ctr = 0; + int err; + + if (!d_inode(index)) + return 0; + + err = -EISDIR; + if (d_is_dir(index)) + goto fail; + + err = -EINVAL; + if (index->d_name.len < sizeof(struct ovl_fh)*2) + goto fail; + + err = -ENOMEM; + len = index->d_name.len / 2; + fh = kzalloc(len, GFP_TEMPORARY); + if (!fh) + goto fail; + + err = -EINVAL; + if (hex2bin((u8 *)fh, index->d_name.name, len) || len != fh->len) + goto fail; + + err = ovl_verify_origin_fh(index, fh); + if (err) + goto fail; + + err = ovl_check_origin(index, lowerstack, numlower, &stack, &ctr); + if (!err && !ctr) + err = -ESTALE; + if (err) + goto fail; + + dput(origin.dentry); +out: + kfree(fh); + return err; + +fail: + pr_warn_ratelimited("overlayfs: failed to verify index (%pd2, err=%i)\n", + index, err); + goto out; +} + +/* * Lookup in indexdir for the index entry of a lower real inode or a copy up * origin inode. The index entry name is the hex representation of the lower * inode file handle. @@ -541,8 +599,8 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, * number - it's the same as if we held a reference * to a dentry in lower layer that was moved under us. */ - err = ovl_check_origin(dentry, upperdentry, - &stack, &ctr); + err = ovl_check_origin(upperdentry, roe->lowerstack, + roe->numlower, &stack, &ctr); if (err) goto out; } diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 437a0301e1b6..f3e49cf34517 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -237,6 +237,8 @@ static inline bool ovl_is_impuredir(struct dentry *dentry) /* namei.c */ int ovl_verify_origin(struct dentry *dentry, struct vfsmount *mnt, struct dentry *origin, bool is_upper, bool set); +int ovl_verify_index(struct dentry *index, struct path *lowerstack, + unsigned int numlower); int ovl_get_index_name(struct dentry *origin, struct qstr *name); int ovl_path_next(int idx, struct dentry *dentry, struct path *path); struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags); @@ -250,6 +252,8 @@ void ovl_cache_free(struct list_head *list); int ovl_check_d_type_supported(struct path *realpath); void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, struct dentry *dentry, int level); +int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt, + struct path *lowerstack, unsigned int numlower); /* inode.c */ int ovl_setattr(struct dentry *dentry, struct iattr *attr); @@ -289,7 +293,7 @@ struct cattr { int ovl_create_real(struct inode *dir, struct dentry *newdentry, struct cattr *attr, struct dentry *hardlink, bool debug); -void ovl_cleanup(struct inode *dir, struct dentry *dentry); +int ovl_cleanup(struct inode *dir, struct dentry *dentry); /* copy_up.c */ int ovl_copy_up(struct dentry *dentry); diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index f241b4ee3d8a..0298463cf9c3 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -667,3 +667,53 @@ void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, ovl_cleanup(dir, dentry); } } + +int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt, + struct path *lowerstack, unsigned int numlower) +{ + int err; + struct inode *dir = dentry->d_inode; + struct path path = { .mnt = mnt, .dentry = dentry }; + LIST_HEAD(list); + struct ovl_cache_entry *p; + struct ovl_readdir_data rdd = { + .ctx.actor = ovl_fill_merge, + .dentry = NULL, + .list = &list, + .root = RB_ROOT, + .is_lowest = false, + }; + + err = ovl_dir_read(&path, &rdd); + if (err) + goto out; + + inode_lock_nested(dir, I_MUTEX_PARENT); + list_for_each_entry(p, &list, l_node) { + struct dentry *index; + + if (p->name[0] == '.') { + if (p->len == 1) + continue; + if (p->len == 2 && p->name[1] == '.') + continue; + } + index = lookup_one_len(p->name, dentry, p->len); + if (IS_ERR(index)) { + err = PTR_ERR(index); + break; + } + if (ovl_verify_index(index, lowerstack, numlower)) { + err = ovl_cleanup(dir, index); + if (err) + break; + } + dput(index); + } + inode_unlock(dir); +out: + ovl_cache_free(&list); + if (err) + pr_err("overlayfs: failed index dir cleanup (%i)\n", err); + return err; +} diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index a313af25dac2..791581c370f5 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1068,6 +1068,12 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) upperpath.dentry, true, true); if (err) pr_err("overlayfs: failed to verify index dir origin\n"); + + /* Cleanup bad/stale index entries */ + if (!err) + err = ovl_indexdir_cleanup(ufs->indexdir, + ufs->upper_mnt, + stack, numlower); } if (err || !ufs->indexdir) pr_warn("overlayfs: try deleting index dir or mounting with '-o index=off' to disable inodes index.\n"); |