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Diffstat (limited to 'fs/overlayfs')
-rw-r--r--fs/overlayfs/copy_up.c2
-rw-r--r--fs/overlayfs/dir.c46
-rw-r--r--fs/overlayfs/export.c6
-rw-r--r--fs/overlayfs/namei.c14
-rw-r--r--fs/overlayfs/overlayfs.h19
-rw-r--r--fs/overlayfs/params.c25
-rw-r--r--fs/overlayfs/readdir.c21
-rw-r--r--fs/overlayfs/super.c28
8 files changed, 92 insertions, 69 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 0c28e5fa3407..d7310fcf3888 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -618,7 +618,6 @@ static int ovl_link_up(struct ovl_copy_up_ctx *c)
err = PTR_ERR(upper);
if (!IS_ERR(upper)) {
err = ovl_do_link(ofs, ovl_dentry_upper(c->dentry), udir, upper);
- dput(upper);
if (!err) {
/* Restore timestamps on parent (best effort) */
@@ -626,6 +625,7 @@ static int ovl_link_up(struct ovl_copy_up_ctx *c)
ovl_dentry_set_upper_alias(c->dentry);
ovl_dentry_update_reval(c->dentry, upper);
}
+ dput(upper);
}
inode_unlock(udir);
if (err)
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index c9993ff66fc2..fe493f3ed6b6 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -138,37 +138,6 @@ kill_whiteout:
goto out;
}
-int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir,
- struct dentry **newdentry, umode_t mode)
-{
- int err;
- struct dentry *d, *dentry = *newdentry;
-
- err = ovl_do_mkdir(ofs, dir, dentry, mode);
- if (err)
- return err;
-
- if (likely(!d_unhashed(dentry)))
- return 0;
-
- /*
- * vfs_mkdir() may succeed and leave the dentry passed
- * to it unhashed and negative. If that happens, try to
- * lookup a new hashed and positive dentry.
- */
- d = ovl_lookup_upper(ofs, dentry->d_name.name, dentry->d_parent,
- dentry->d_name.len);
- if (IS_ERR(d)) {
- pr_warn("failed lookup after mkdir (%pd2, err=%i).\n",
- dentry, err);
- return PTR_ERR(d);
- }
- dput(dentry);
- *newdentry = d;
-
- return 0;
-}
-
struct dentry *ovl_create_real(struct ovl_fs *ofs, struct inode *dir,
struct dentry *newdentry, struct ovl_cattr *attr)
{
@@ -191,7 +160,8 @@ struct dentry *ovl_create_real(struct ovl_fs *ofs, struct inode *dir,
case S_IFDIR:
/* mkdir is special... */
- err = ovl_mkdir_real(ofs, dir, &newdentry, attr->mode);
+ newdentry = ovl_do_mkdir(ofs, dir, newdentry, attr->mode);
+ err = PTR_ERR_OR_ZERO(newdentry);
break;
case S_IFCHR:
@@ -219,7 +189,8 @@ struct dentry *ovl_create_real(struct ovl_fs *ofs, struct inode *dir,
}
out:
if (err) {
- dput(newdentry);
+ if (!IS_ERR(newdentry))
+ dput(newdentry);
return ERR_PTR(err);
}
return newdentry;
@@ -282,7 +253,8 @@ static int ovl_instantiate(struct dentry *dentry, struct inode *inode,
* XXX: if we ever use ovl_obtain_alias() to decode directory
* file handles, need to use ovl_get_inode_locked() and
* d_instantiate_new() here to prevent from creating two
- * hashed directory inode aliases.
+ * hashed directory inode aliases. We then need to return
+ * the obtained alias to ovl_mkdir().
*/
inode = ovl_get_inode(dentry->d_sb, &oip);
if (IS_ERR(inode))
@@ -687,10 +659,10 @@ static int ovl_create(struct mnt_idmap *idmap, struct inode *dir,
return ovl_create_object(dentry, (mode & 07777) | S_IFREG, 0, NULL);
}
-static int ovl_mkdir(struct mnt_idmap *idmap, struct inode *dir,
- struct dentry *dentry, umode_t mode)
+static struct dentry *ovl_mkdir(struct mnt_idmap *idmap, struct inode *dir,
+ struct dentry *dentry, umode_t mode)
{
- return ovl_create_object(dentry, (mode & 07777) | S_IFDIR, 0, NULL);
+ return ERR_PTR(ovl_create_object(dentry, (mode & 07777) | S_IFDIR, 0, NULL));
}
static int ovl_mknod(struct mnt_idmap *idmap, struct inode *dir,
diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c
index 444aeeccb6da..83f80fdb1567 100644
--- a/fs/overlayfs/export.c
+++ b/fs/overlayfs/export.c
@@ -385,11 +385,9 @@ static struct dentry *ovl_lookup_real_one(struct dentry *connected,
*/
take_dentry_name_snapshot(&name, real);
/*
- * No idmap handling here: it's an internal lookup. Could skip
- * permission checking altogether, but for now just use non-idmap
- * transformed ids.
+ * No idmap handling here: it's an internal lookup.
*/
- this = lookup_one_len(name.name.name, connected, name.name.len);
+ this = lookup_noperm(&name.name, connected);
release_dentry_name_snapshot(&name);
err = PTR_ERR(this);
if (IS_ERR(this)) {
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index be5c65d6f848..bf722daf19a9 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -205,8 +205,8 @@ static struct dentry *ovl_lookup_positive_unlocked(struct ovl_lookup_data *d,
struct dentry *base, int len,
bool drop_negative)
{
- struct dentry *ret = lookup_one_unlocked(mnt_idmap(d->layer->mnt), name,
- base, len);
+ struct dentry *ret = lookup_one_unlocked(mnt_idmap(d->layer->mnt),
+ &QSTR_LEN(name, len), base);
if (!IS_ERR(ret) && d_flags_negative(smp_load_acquire(&ret->d_flags))) {
if (drop_negative && ret->d_lockref.count == 1) {
@@ -757,7 +757,7 @@ struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh)
if (err)
return ERR_PTR(err);
- index = lookup_positive_unlocked(name.name, ofs->workdir, name.len);
+ index = lookup_noperm_positive_unlocked(&name, ofs->workdir);
kfree(name.name);
if (IS_ERR(index)) {
if (PTR_ERR(index) == -ENOENT)
@@ -789,8 +789,8 @@ struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
if (err)
return ERR_PTR(err);
- index = lookup_one_positive_unlocked(ovl_upper_mnt_idmap(ofs), name.name,
- ofs->workdir, name.len);
+ index = lookup_one_positive_unlocked(ovl_upper_mnt_idmap(ofs), &name,
+ ofs->workdir);
if (IS_ERR(index)) {
err = PTR_ERR(index);
if (err == -ENOENT) {
@@ -1371,7 +1371,7 @@ out:
bool ovl_lower_positive(struct dentry *dentry)
{
struct ovl_entry *poe = OVL_E(dentry->d_parent);
- const struct qstr *name = &dentry->d_name;
+ struct qstr *name = &dentry->d_name;
const struct cred *old_cred;
unsigned int i;
bool positive = false;
@@ -1396,7 +1396,7 @@ bool ovl_lower_positive(struct dentry *dentry)
this = lookup_one_positive_unlocked(
mnt_idmap(parentpath->layer->mnt),
- name->name, parentpath->dentry, name->len);
+ name, parentpath->dentry);
if (IS_ERR(this)) {
switch (PTR_ERR(this)) {
case -ENOENT:
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 0021e2025020..8baaba0a3fe5 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -241,13 +241,14 @@ static inline int ovl_do_create(struct ovl_fs *ofs,
return err;
}
-static inline int ovl_do_mkdir(struct ovl_fs *ofs,
- struct inode *dir, struct dentry *dentry,
- umode_t mode)
+static inline struct dentry *ovl_do_mkdir(struct ovl_fs *ofs,
+ struct inode *dir,
+ struct dentry *dentry,
+ umode_t mode)
{
- int err = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode);
- pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
- return err;
+ dentry = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode);
+ pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, PTR_ERR_OR_ZERO(dentry));
+ return dentry;
}
static inline int ovl_do_mknod(struct ovl_fs *ofs,
@@ -401,7 +402,7 @@ static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs,
const char *name,
struct dentry *base, int len)
{
- return lookup_one(ovl_upper_mnt_idmap(ofs), name, base, len);
+ return lookup_one(ovl_upper_mnt_idmap(ofs), &QSTR_LEN(name, len), base);
}
static inline bool ovl_open_flags_need_copy_up(int flags)
@@ -540,8 +541,6 @@ int ovl_set_metacopy_xattr(struct ovl_fs *ofs, struct dentry *d,
bool ovl_is_metacopy_dentry(struct dentry *dentry);
char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding);
int ovl_ensure_verity_loaded(struct path *path);
-int ovl_get_verity_xattr(struct ovl_fs *ofs, const struct path *path,
- u8 *digest_buf, int *buf_length);
int ovl_validate_verity(struct ovl_fs *ofs,
struct path *metapath,
struct path *datapath);
@@ -838,8 +837,6 @@ struct ovl_cattr {
#define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) })
-int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir,
- struct dentry **newdentry, umode_t mode);
struct dentry *ovl_create_real(struct ovl_fs *ofs,
struct inode *dir, struct dentry *newdentry,
struct ovl_cattr *attr);
diff --git a/fs/overlayfs/params.c b/fs/overlayfs/params.c
index 1115c22deca0..6759f7d040c8 100644
--- a/fs/overlayfs/params.c
+++ b/fs/overlayfs/params.c
@@ -59,6 +59,7 @@ enum ovl_opt {
Opt_metacopy,
Opt_verity,
Opt_volatile,
+ Opt_override_creds,
};
static const struct constant_table ovl_parameter_bool[] = {
@@ -155,6 +156,7 @@ const struct fs_parameter_spec ovl_parameter_spec[] = {
fsparam_enum("metacopy", Opt_metacopy, ovl_parameter_bool),
fsparam_enum("verity", Opt_verity, ovl_parameter_verity),
fsparam_flag("volatile", Opt_volatile),
+ fsparam_flag_no("override_creds", Opt_override_creds),
{}
};
@@ -662,6 +664,29 @@ static int ovl_parse_param(struct fs_context *fc, struct fs_parameter *param)
case Opt_userxattr:
config->userxattr = true;
break;
+ case Opt_override_creds: {
+ const struct cred *cred = NULL;
+
+ if (result.negated) {
+ swap(cred, ofs->creator_cred);
+ put_cred(cred);
+ break;
+ }
+
+ if (!current_in_userns(fc->user_ns)) {
+ err = -EINVAL;
+ break;
+ }
+
+ cred = prepare_creds();
+ if (cred)
+ swap(cred, ofs->creator_cred);
+ else
+ err = -ENOMEM;
+
+ put_cred(cred);
+ break;
+ }
default:
pr_err("unrecognized mount option \"%s\" or missing value\n",
param->key);
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 881ec5592da5..44e208da417c 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -271,7 +271,6 @@ static bool ovl_fill_merge(struct dir_context *ctx, const char *name,
static int ovl_check_whiteouts(const struct path *path, struct ovl_readdir_data *rdd)
{
int err;
- struct ovl_cache_entry *p;
struct dentry *dentry, *dir = path->dentry;
const struct cred *old_cred;
@@ -280,9 +279,11 @@ static int ovl_check_whiteouts(const struct path *path, struct ovl_readdir_data
err = down_write_killable(&dir->d_inode->i_rwsem);
if (!err) {
while (rdd->first_maybe_whiteout) {
- p = rdd->first_maybe_whiteout;
+ struct ovl_cache_entry *p =
+ rdd->first_maybe_whiteout;
rdd->first_maybe_whiteout = p->next_maybe_whiteout;
- dentry = lookup_one(mnt_idmap(path->mnt), p->name, dir, p->len);
+ dentry = lookup_one(mnt_idmap(path->mnt),
+ &QSTR_LEN(p->name, p->len), dir);
if (!IS_ERR(dentry)) {
p->is_whiteout = ovl_is_whiteout(dentry);
dput(dentry);
@@ -351,6 +352,7 @@ static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list,
struct path realpath;
struct ovl_readdir_data rdd = {
.ctx.actor = ovl_fill_merge,
+ .ctx.count = INT_MAX,
.dentry = dentry,
.list = list,
.root = root,
@@ -492,7 +494,7 @@ static int ovl_cache_update(const struct path *path, struct ovl_cache_entry *p,
}
}
/* This checks also for xwhiteouts */
- this = lookup_one(mnt_idmap(path->mnt), p->name, dir, p->len);
+ this = lookup_one(mnt_idmap(path->mnt), &QSTR_LEN(p->name, p->len), dir);
if (IS_ERR_OR_NULL(this) || !this->d_inode) {
/* Mark a stale entry */
p->is_whiteout = true;
@@ -571,6 +573,7 @@ static int ovl_dir_read_impure(const struct path *path, struct list_head *list,
struct ovl_cache_entry *p, *n;
struct ovl_readdir_data rdd = {
.ctx.actor = ovl_fill_plain,
+ .ctx.count = INT_MAX,
.list = list,
.root = root,
};
@@ -672,6 +675,7 @@ static bool ovl_fill_real(struct dir_context *ctx, const char *name,
struct ovl_readdir_translate *rdt =
container_of(ctx, struct ovl_readdir_translate, ctx);
struct dir_context *orig_ctx = rdt->orig_ctx;
+ bool res;
if (rdt->parent_ino && strcmp(name, "..") == 0) {
ino = rdt->parent_ino;
@@ -686,7 +690,10 @@ static bool ovl_fill_real(struct dir_context *ctx, const char *name,
name, namelen, rdt->xinowarn);
}
- return orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type);
+ res = orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type);
+ ctx->count = orig_ctx->count;
+
+ return res;
}
static bool ovl_is_impure_dir(struct file *file)
@@ -713,6 +720,7 @@ static int ovl_iterate_real(struct file *file, struct dir_context *ctx)
const struct ovl_layer *lower_layer = ovl_layer_lower(dir);
struct ovl_readdir_translate rdt = {
.ctx.actor = ovl_fill_real,
+ .ctx.count = ctx->count,
.orig_ctx = ctx,
.xinobits = ovl_xino_bits(ofs),
.xinowarn = ovl_xino_warn(ofs),
@@ -1073,6 +1081,7 @@ int ovl_check_d_type_supported(const struct path *realpath)
int err;
struct ovl_readdir_data rdd = {
.ctx.actor = ovl_check_d_type,
+ .ctx.count = INT_MAX,
.d_type_supported = false,
};
@@ -1094,6 +1103,7 @@ static int ovl_workdir_cleanup_recurse(struct ovl_fs *ofs, const struct path *pa
struct ovl_cache_entry *p;
struct ovl_readdir_data rdd = {
.ctx.actor = ovl_fill_plain,
+ .ctx.count = INT_MAX,
.list = &list,
};
bool incompat = false;
@@ -1178,6 +1188,7 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs)
struct ovl_cache_entry *p;
struct ovl_readdir_data rdd = {
.ctx.actor = ovl_fill_plain,
+ .ctx.count = INT_MAX,
.list = &list,
};
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 86ae6f6da36b..e19940d649ca 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -327,9 +327,10 @@ retry:
goto retry;
}
- err = ovl_mkdir_real(ofs, dir, &work, attr.ia_mode);
- if (err)
- goto out_dput;
+ work = ovl_do_mkdir(ofs, dir, work, attr.ia_mode);
+ err = PTR_ERR(work);
+ if (IS_ERR(work))
+ goto out_err;
/* Weird filesystem returning with hashed negative (kernfs)? */
err = -EINVAL;
@@ -1137,6 +1138,11 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
return ERR_PTR(-EINVAL);
}
+ if (ctx->nr == ctx->nr_data) {
+ pr_err("at least one non-data lowerdir is required\n");
+ return ERR_PTR(-EINVAL);
+ }
+
err = -EINVAL;
for (i = 0; i < ctx->nr; i++) {
l = &ctx->lower[i];
@@ -1305,6 +1311,7 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct ovl_fs *ofs = sb->s_fs_info;
struct ovl_fs_context *ctx = fc->fs_private;
+ const struct cred *old_cred = NULL;
struct dentry *root_dentry;
struct ovl_entry *oe;
struct ovl_layer *layers;
@@ -1318,10 +1325,15 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
sb->s_d_op = &ovl_dentry_operations;
err = -ENOMEM;
- ofs->creator_cred = cred = prepare_creds();
+ if (!ofs->creator_cred)
+ ofs->creator_cred = cred = prepare_creds();
+ else
+ cred = (struct cred *)ofs->creator_cred;
if (!cred)
goto out_err;
+ old_cred = ovl_override_creds(sb);
+
err = ovl_fs_params_verify(ctx, &ofs->config);
if (err)
goto out_err;
@@ -1481,11 +1493,19 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)
sb->s_root = root_dentry;
+ ovl_revert_creds(old_cred);
return 0;
out_free_oe:
ovl_free_entry(oe);
out_err:
+ /*
+ * Revert creds before calling ovl_free_fs() which will call
+ * put_cred() and put_cred() requires that the cred's that are
+ * put are not the caller's creds, i.e., current->cred.
+ */
+ if (old_cred)
+ ovl_revert_creds(old_cred);
ovl_free_fs(ofs);
sb->s_fs_info = NULL;
return err;
generated by cgit (git 2.34.1) at 2025-06-01 17:35:18 +0000