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ovl: port ovl_create_tmpfile() to cred guard 

Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-6-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2025-11-17 10:33:37 +01:00
parent 8368eb837e
commit 5f51dfe768
No known key found for this signature in database
GPG Key ID: 91C61BC06578DCA2
1 changed files with 26 additions and 32 deletions
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58
fs/overlayfs/dir.c
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@ -1317,7 +1317,7 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir,
static int ovl_create_tmpfile(struct file *file, struct dentry *dentry,
struct inode *inode, umode_t mode)
{
const struct cred *old_cred, *new_cred = NULL;
const struct cred *new_cred __free(put_cred) = NULL;
struct path realparentpath;
struct file *realfile;
struct ovl_file *of;
@ -1326,41 +1326,35 @@ static int ovl_create_tmpfile(struct file *file, struct dentry *dentry,
int flags = file->f_flags | OVL_OPEN_FLAGS;
int err;
old_cred = ovl_override_creds(dentry->d_sb);
new_cred = ovl_setup_cred_for_create(dentry, inode, mode, old_cred);
err = PTR_ERR(new_cred);
if (IS_ERR(new_cred)) {
new_cred = NULL;
goto out_revert_creds;
}
scoped_class(override_creds_ovl, old_cred, dentry->d_sb) {
new_cred = ovl_setup_cred_for_create(dentry, inode, mode, old_cred);
if (IS_ERR(new_cred))
return PTR_ERR(new_cred);
ovl_path_upper(dentry->d_parent, &realparentpath);
realfile = backing_tmpfile_open(&file->f_path, flags, &realparentpath,
mode, current_cred());
err = PTR_ERR_OR_ZERO(realfile);
pr_debug("tmpfile/open(%pd2, 0%o) = %i\n", realparentpath.dentry, mode, err);
if (err)
goto out_revert_creds;
ovl_path_upper(dentry->d_parent, &realparentpath);
realfile = backing_tmpfile_open(&file->f_path, flags, &realparentpath,
mode, current_cred());
err = PTR_ERR_OR_ZERO(realfile);
pr_debug("tmpfile/open(%pd2, 0%o) = %i\n", realparentpath.dentry, mode, err);
if (err)
return err;
of = ovl_file_alloc(realfile);
if (!of) {
fput(realfile);
err = -ENOMEM;
goto out_revert_creds;
}
of = ovl_file_alloc(realfile);
if (!of) {
fput(realfile);
return -ENOMEM;
}
/* ovl_instantiate() consumes the newdentry reference on success */
newdentry = dget(realfile->f_path.dentry);
err = ovl_instantiate(dentry, inode, newdentry, false, file);
if (!err) {
file->private_data = of;
} else {
dput(newdentry);
ovl_file_free(of);
/* ovl_instantiate() consumes the newdentry reference on success */
newdentry = dget(realfile->f_path.dentry);
err = ovl_instantiate(dentry, inode, newdentry, false, file);
if (!err) {
file->private_data = of;
} else {
dput(newdentry);
ovl_file_free(of);
}
}
out_revert_creds:
ovl_revert_creds(old_cred);
put_cred(new_cred);
return err;
}