From db7cfe87832d34bd9720d961f0e9176721c456a8 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Mon, 17 Nov 2025 10:34:10 +0100 Subject: [PATCH] ovl: port ovl_lower_positive() to cred guard Use the scoped ovl cred guard. Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-39-b31603935724@kernel.org Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner --- fs/overlayfs/namei.c | 72 +++++++++++++++++++++----------------------- 1 file changed, 35 insertions(+), 37 deletions(-) diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index 61c2dbd49b6fe..e9a69c95be918 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -1418,7 +1418,6 @@ bool ovl_lower_positive(struct dentry *dentry) { struct ovl_entry *poe = OVL_E(dentry->d_parent); const struct qstr *name = &dentry->d_name; - const struct cred *old_cred; unsigned int i; bool positive = false; bool done = false; @@ -1434,46 +1433,45 @@ bool ovl_lower_positive(struct dentry *dentry) if (!ovl_dentry_upper(dentry)) return true; - old_cred = ovl_override_creds(dentry->d_sb); - /* Positive upper -> have to look up lower to see whether it exists */ - for (i = 0; !done && !positive && i < ovl_numlower(poe); i++) { - struct dentry *this; - struct ovl_path *parentpath = &ovl_lowerstack(poe)[i]; + with_ovl_creds(dentry->d_sb) { + /* Positive upper -> have to look up lower to see whether it exists */ + for (i = 0; !done && !positive && i < ovl_numlower(poe); i++) { + 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), - &QSTR_LEN(name->name, name->len), - parentpath->dentry); - if (IS_ERR(this)) { - switch (PTR_ERR(this)) { - case -ENOENT: - case -ENAMETOOLONG: - break; - - default: - /* - * Assume something is there, we just couldn't - * access it. - */ - positive = true; - break; + /* + * 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), + &QSTR_LEN(name->name, name->len), + parentpath->dentry); + if (IS_ERR(this)) { + switch (PTR_ERR(this)) { + case -ENOENT: + case -ENAMETOOLONG: + break; + + default: + /* + * Assume something is there, we just couldn't + * access it. + */ + positive = true; + break; + } + } else { + struct path path = { + .dentry = this, + .mnt = parentpath->layer->mnt, + }; + positive = !ovl_path_is_whiteout(OVL_FS(dentry->d_sb), &path); + done = true; + dput(this); } - } else { - struct path path = { - .dentry = this, - .mnt = parentpath->layer->mnt, - }; - positive = !ovl_path_is_whiteout(OVL_FS(dentry->d_sb), &path); - done = true; - dput(this); } } - ovl_revert_creds(old_cred); return positive; } -- 2.47.3