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Diffstat (limited to 'fs/overlayfs')
-rw-r--r--fs/overlayfs/dir.c46
-rw-r--r--fs/overlayfs/export.c6
-rw-r--r--fs/overlayfs/file.c4
-rw-r--r--fs/overlayfs/namei.c116
-rw-r--r--fs/overlayfs/overlayfs.h19
-rw-r--r--fs/overlayfs/ovl_entry.h2
-rw-r--r--fs/overlayfs/params.c65
-rw-r--r--fs/overlayfs/readdir.c25
-rw-r--r--fs/overlayfs/super.c23
-rw-r--r--fs/overlayfs/util.c9
10 files changed, 170 insertions, 145 deletions
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/file.c b/fs/overlayfs/file.c
index 969b458100fe..dfea7bd800cb 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -48,8 +48,8 @@ static struct file *ovl_open_realfile(const struct file *file,
if (!inode_owner_or_capable(real_idmap, realinode))
flags &= ~O_NOATIME;
- realfile = backing_file_open(&file->f_path, flags, realpath,
- current_cred());
+ realfile = backing_file_open(file_user_path((struct file *) file),
+ flags, realpath, current_cred());
}
ovl_revert_creds(old_cred);
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index be5c65d6f848..2043f0369059 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -16,6 +16,7 @@
struct ovl_lookup_data {
struct super_block *sb;
+ struct dentry *dentry;
const struct ovl_layer *layer;
struct qstr name;
bool is_dir;
@@ -24,6 +25,7 @@ struct ovl_lookup_data {
bool stop;
bool last;
char *redirect;
+ char *upperredirect;
int metacopy;
/* Referring to last redirect xattr */
bool absolute_redirect;
@@ -205,8 +207,8 @@ 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 +759,7 @@ 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 +791,8 @@ 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) {
@@ -1024,6 +1026,31 @@ int ovl_verify_lowerdata(struct dentry *dentry)
return ovl_maybe_validate_verity(dentry);
}
+/*
+ * Following redirects/metacopy can have security consequences: it's like a
+ * symlink into the lower layer without the permission checks.
+ *
+ * This is only a problem if the upper layer is untrusted (e.g comes from an USB
+ * drive). This can allow a non-readable file or directory to become readable.
+ *
+ * Only following redirects when redirects are enabled disables this attack
+ * vector when not necessary.
+ */
+static bool ovl_check_follow_redirect(struct ovl_lookup_data *d)
+{
+ struct ovl_fs *ofs = OVL_FS(d->sb);
+
+ if (d->metacopy && !ofs->config.metacopy) {
+ pr_warn_ratelimited("refusing to follow metacopy origin for (%pd2)\n", d->dentry);
+ return false;
+ }
+ if ((d->redirect || d->upperredirect) && !ovl_redirect_follow(ofs)) {
+ pr_warn_ratelimited("refusing to follow redirect for (%pd2)\n", d->dentry);
+ return false;
+ }
+ return true;
+}
+
struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
@@ -1039,7 +1066,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
unsigned int ctr = 0;
struct inode *inode = NULL;
bool upperopaque = false;
- char *upperredirect = NULL;
+ bool check_redirect = (ovl_redirect_follow(ofs) || ofs->numdatalayer);
struct dentry *this;
unsigned int i;
int err;
@@ -1047,12 +1074,14 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
int metacopy_size = 0;
struct ovl_lookup_data d = {
.sb = dentry->d_sb,
+ .dentry = dentry,
.name = dentry->d_name,
.is_dir = false,
.opaque = false,
.stop = false,
- .last = ovl_redirect_follow(ofs) ? false : !ovl_numlower(poe),
+ .last = check_redirect ? false : !ovl_numlower(poe),
.redirect = NULL,
+ .upperredirect = NULL,
.metacopy = 0,
};
@@ -1094,8 +1123,8 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
if (d.redirect) {
err = -ENOMEM;
- upperredirect = kstrdup(d.redirect, GFP_KERNEL);
- if (!upperredirect)
+ d.upperredirect = kstrdup(d.redirect, GFP_KERNEL);
+ if (!d.upperredirect)
goto out_put_upper;
if (d.redirect[0] == '/')
poe = roe;
@@ -1113,7 +1142,12 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
for (i = 0; !d.stop && i < ovl_numlower(poe); i++) {
struct ovl_path lower = ovl_lowerstack(poe)[i];
- if (!ovl_redirect_follow(ofs))
+ if (!ovl_check_follow_redirect(&d)) {
+ err = -EPERM;
+ goto out_put;
+ }
+
+ if (!check_redirect)
d.last = i == ovl_numlower(poe) - 1;
else if (d.is_dir || !ofs->numdatalayer)
d.last = lower.layer->idx == ovl_numlower(roe);
@@ -1126,13 +1160,6 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
if (!this)
continue;
- if ((uppermetacopy || d.metacopy) && !ofs->config.metacopy) {
- dput(this);
- err = -EPERM;
- pr_warn_ratelimited("refusing to follow metacopy origin for (%pd2)\n", dentry);
- goto out_put;
- }
-
/*
* If no origin fh is stored in upper of a merge dir, store fh
* of lower dir and set upper parent "impure".
@@ -1185,23 +1212,6 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
ctr++;
}
- /*
- * Following redirects can have security consequences: it's like
- * a symlink into the lower layer without the permission checks.
- * This is only a problem if the upper layer is untrusted (e.g
- * comes from an USB drive). This can allow a non-readable file
- * or directory to become readable.
- *
- * Only following redirects when redirects are enabled disables
- * this attack vector when not necessary.
- */
- err = -EPERM;
- if (d.redirect && !ovl_redirect_follow(ofs)) {
- pr_warn_ratelimited("refusing to follow redirect for (%pd2)\n",
- dentry);
- goto out_put;
- }
-
if (d.stop)
break;
@@ -1212,10 +1222,16 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
}
}
- /* Defer lookup of lowerdata in data-only layers to first access */
+ /*
+ * Defer lookup of lowerdata in data-only layers to first access.
+ * Don't require redirect=follow and metacopy=on in this case.
+ */
if (d.metacopy && ctr && ofs->numdatalayer && d.absolute_redirect) {
d.metacopy = 0;
ctr++;
+ } else if (!ovl_check_follow_redirect(&d)) {
+ err = -EPERM;
+ goto out_put;
}
/*
@@ -1298,20 +1314,26 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
/*
* It's safe to assign upperredirect here: the previous
- * assignment of happens only if upperdentry is non-NULL, and
+ * assignment happens only if upperdentry is non-NULL, and
* this one only if upperdentry is NULL.
*/
- upperredirect = ovl_get_redirect_xattr(ofs, &upperpath, 0);
- if (IS_ERR(upperredirect)) {
- err = PTR_ERR(upperredirect);
- upperredirect = NULL;
+ d.upperredirect = ovl_get_redirect_xattr(ofs, &upperpath, 0);
+ if (IS_ERR(d.upperredirect)) {
+ err = PTR_ERR(d.upperredirect);
+ d.upperredirect = NULL;
goto out_free_oe;
}
+
err = ovl_check_metacopy_xattr(ofs, &upperpath, NULL);
if (err < 0)
goto out_free_oe;
- uppermetacopy = err;
+ d.metacopy = uppermetacopy = err;
metacopy_size = err;
+
+ if (!ovl_check_follow_redirect(&d)) {
+ err = -EPERM;
+ goto out_free_oe;
+ }
}
if (upperdentry || ctr) {
@@ -1319,7 +1341,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
.upperdentry = upperdentry,
.oe = oe,
.index = index,
- .redirect = upperredirect,
+ .redirect = d.upperredirect,
};
/* Store lowerdata redirect for lazy lookup */
@@ -1361,7 +1383,7 @@ out_put_upper:
kfree(origin_path);
}
dput(upperdentry);
- kfree(upperredirect);
+ kfree(d.upperredirect);
out:
kfree(d.redirect);
ovl_revert_creds(old_cred);
@@ -1394,9 +1416,15 @@ bool ovl_lower_positive(struct dentry *dentry)
struct dentry *this;
struct ovl_path *parentpath = &ovl_lowerstack(poe)[i];
+ /*
+ * We need to make a non-const copy of dentry->d_name,
+ * because lookup_one_positive_unlocked() will hash name
+ * with parentpath base, which is on another (lower fs).
+ */
this = lookup_one_positive_unlocked(
mnt_idmap(parentpath->layer->mnt),
- name->name, parentpath->dentry, name->len);
+ &QSTR_LEN(name->name, name->len),
+ 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 be86d2ed71d6..497323128e5f 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -241,13 +241,16 @@ 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;
+ struct dentry *ret;
+
+ ret = vfs_mkdir(ovl_upper_mnt_idmap(ofs), dir, dentry, mode);
+ pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, PTR_ERR_OR_ZERO(ret));
+ return ret;
}
static inline int ovl_do_mknod(struct ovl_fs *ofs,
@@ -401,7 +404,7 @@ 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)
@@ -836,8 +839,6 @@ 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/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index cb449ab310a7..afb7762f873f 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -51,7 +51,7 @@ struct ovl_path {
struct ovl_entry {
unsigned int __numlower;
- struct ovl_path __lowerstack[];
+ struct ovl_path __lowerstack[] __counted_by(__numlower);
};
/* private information held for overlayfs's superblock */
diff --git a/fs/overlayfs/params.c b/fs/overlayfs/params.c
index 1115c22deca0..f42488c01957 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);
@@ -846,18 +871,6 @@ int ovl_fs_params_verify(const struct ovl_fs_context *ctx,
config->uuid = OVL_UUID_NULL;
}
- /* Resolve verity -> metacopy dependency */
- if (config->verity_mode && !config->metacopy) {
- /* Don't allow explicit specified conflicting combinations */
- if (set.metacopy) {
- pr_err("conflicting options: metacopy=off,verity=%s\n",
- ovl_verity_mode(config));
- return -EINVAL;
- }
- /* Otherwise automatically enable metacopy. */
- config->metacopy = true;
- }
-
/*
* This is to make the logic below simpler. It doesn't make any other
* difference, since redirect_dir=on is only used for upper.
@@ -865,18 +878,13 @@ int ovl_fs_params_verify(const struct ovl_fs_context *ctx,
if (!config->upperdir && config->redirect_mode == OVL_REDIRECT_FOLLOW)
config->redirect_mode = OVL_REDIRECT_ON;
- /* Resolve verity -> metacopy -> redirect_dir dependency */
+ /* metacopy -> redirect_dir dependency */
if (config->metacopy && config->redirect_mode != OVL_REDIRECT_ON) {
if (set.metacopy && set.redirect) {
pr_err("conflicting options: metacopy=on,redirect_dir=%s\n",
ovl_redirect_mode(config));
return -EINVAL;
}
- if (config->verity_mode && set.redirect) {
- pr_err("conflicting options: verity=%s,redirect_dir=%s\n",
- ovl_verity_mode(config), ovl_redirect_mode(config));
- return -EINVAL;
- }
if (set.redirect) {
/*
* There was an explicit redirect_dir=... that resulted
@@ -945,7 +953,7 @@ int ovl_fs_params_verify(const struct ovl_fs_context *ctx,
}
- /* Resolve userxattr -> !redirect && !metacopy && !verity dependency */
+ /* Resolve userxattr -> !redirect && !metacopy dependency */
if (config->userxattr) {
if (set.redirect &&
config->redirect_mode != OVL_REDIRECT_NOFOLLOW) {
@@ -957,11 +965,6 @@ int ovl_fs_params_verify(const struct ovl_fs_context *ctx,
pr_err("conflicting options: userxattr,metacopy=on\n");
return -EINVAL;
}
- if (config->verity_mode) {
- pr_err("conflicting options: userxattr,verity=%s\n",
- ovl_verity_mode(config));
- return -EINVAL;
- }
/*
* Silently disable default setting of redirect and metacopy.
* This shall be the default in the future as well: these
@@ -1000,11 +1003,6 @@ int ovl_fs_params_verify(const struct ovl_fs_context *ctx,
*/
}
- if (ctx->nr_data > 0 && !config->metacopy) {
- pr_err("lower data-only dirs require metacopy support.\n");
- return -EINVAL;
- }
-
return 0;
}
@@ -1053,17 +1051,16 @@ int ovl_show_options(struct seq_file *m, struct dentry *dentry)
seq_printf(m, ",redirect_dir=%s",
ovl_redirect_mode(&ofs->config));
if (ofs->config.index != ovl_index_def)
- seq_printf(m, ",index=%s", ofs->config.index ? "on" : "off");
+ seq_printf(m, ",index=%s", str_on_off(ofs->config.index));
if (ofs->config.uuid != ovl_uuid_def())
seq_printf(m, ",uuid=%s", ovl_uuid_mode(&ofs->config));
if (ofs->config.nfs_export != ovl_nfs_export_def)
- seq_printf(m, ",nfs_export=%s", ofs->config.nfs_export ?
- "on" : "off");
+ seq_printf(m, ",nfs_export=%s",
+ str_on_off(ofs->config.nfs_export));
if (ofs->config.xino != ovl_xino_def() && !ovl_same_fs(ofs))
seq_printf(m, ",xino=%s", ovl_xino_mode(&ofs->config));
if (ofs->config.metacopy != ovl_metacopy_def)
- seq_printf(m, ",metacopy=%s",
- ofs->config.metacopy ? "on" : "off");
+ seq_printf(m, ",metacopy=%s", str_on_off(ofs->config.metacopy));
if (ofs->config.ovl_volatile)
seq_puts(m, ",volatile");
if (ofs->config.userxattr)
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 881ec5592da5..474c80d210d1 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -13,6 +13,7 @@
#include <linux/security.h>
#include <linux/cred.h>
#include <linux/ratelimit.h>
+#include <linux/overflow.h>
#include "overlayfs.h"
struct ovl_cache_entry {
@@ -147,9 +148,8 @@ static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd,
u64 ino, unsigned int d_type)
{
struct ovl_cache_entry *p;
- size_t size = offsetof(struct ovl_cache_entry, name[len + 1]);
- p = kmalloc(size, GFP_KERNEL);
+ p = kmalloc(struct_size(p, name, len + 1), GFP_KERNEL);
if (!p)
return NULL;
@@ -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 b11094acdd8f..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;
@@ -1310,6 +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;
@@ -1323,10 +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;
@@ -1486,11 +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;
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 0819c739cc2f..dcccb4b4a66c 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -15,6 +15,7 @@
#include <linux/uuid.h>
#include <linux/namei.h>
#include <linux/ratelimit.h>
+#include <linux/overflow.h>
#include "overlayfs.h"
/* Get write access to upper mnt - may fail if upper sb was remounted ro */
@@ -145,9 +146,9 @@ void ovl_stack_free(struct ovl_path *stack, unsigned int n)
struct ovl_entry *ovl_alloc_entry(unsigned int numlower)
{
- size_t size = offsetof(struct ovl_entry, __lowerstack[numlower]);
- struct ovl_entry *oe = kzalloc(size, GFP_KERNEL);
+ struct ovl_entry *oe;
+ oe = kzalloc(struct_size(oe, __lowerstack, numlower), GFP_KERNEL);
if (oe)
oe->__numlower = numlower;
@@ -305,7 +306,9 @@ enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path)
struct dentry *ovl_dentry_upper(struct dentry *dentry)
{
- return ovl_upperdentry_dereference(OVL_I(d_inode(dentry)));
+ struct inode *inode = d_inode(dentry);
+
+ return inode ? ovl_upperdentry_dereference(OVL_I(inode)) : NULL;
}
struct dentry *ovl_dentry_lower(struct dentry *dentry)
generated by cgit v1.2.3 (git 2.39.0) at 2025-08-21 06:34:35 +0300