diff options
author | Amir Goldstein <amir73il@gmail.com> | 2024-11-14 09:36:35 +0100 |
---|---|---|
committer | Amir Goldstein <amir73il@gmail.com> | 2024-11-14 13:15:46 +0100 |
commit | 711747e204ead127235aa41b350e518e92a87fcc (patch) | |
tree | ce95f3deeb06147510da6a1596bebe5b5a214b14 /fs/overlayfs | |
parent | fc5a1d2287bf23f67da1fc7a178cf26c5e6ba9d0 (diff) |
ovl: pass an explicit reference of creators creds to callers
ovl_setup_cred_for_create() decrements one refcount of new creds and
ovl_revert_creds() in callers decrements the last refcount.
In preparation to revert_creds_light() back to caller creds, pass an
explicit reference of the creators creds to the callers and drop the
refcount explicitly in the callers after ovl_revert_creds().
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Diffstat (limited to 'fs/overlayfs')
-rw-r--r-- | fs/overlayfs/dir.c | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 09db5eb19242..4b0bb7a91d37 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -553,15 +553,17 @@ out_cleanup: goto out_dput; } -static int ovl_setup_cred_for_create(struct dentry *dentry, struct inode *inode, - umode_t mode, const struct cred *old_cred) +static const struct cred *ovl_setup_cred_for_create(struct dentry *dentry, + struct inode *inode, + umode_t mode, + const struct cred *old_cred) { int err; struct cred *override_cred; override_cred = prepare_creds(); if (!override_cred) - return -ENOMEM; + return ERR_PTR(-ENOMEM); override_cred->fsuid = inode->i_uid; override_cred->fsgid = inode->i_gid; @@ -569,19 +571,18 @@ static int ovl_setup_cred_for_create(struct dentry *dentry, struct inode *inode, old_cred, override_cred); if (err) { put_cred(override_cred); - return err; + return ERR_PTR(err); } put_cred(override_creds(override_cred)); - put_cred(override_cred); - return 0; + return override_cred; } static int ovl_create_or_link(struct dentry *dentry, struct inode *inode, struct ovl_cattr *attr, bool origin) { int err; - const struct cred *old_cred; + const struct cred *old_cred, *new_cred = NULL; struct dentry *parent = dentry->d_parent; old_cred = ovl_override_creds(dentry->d_sb); @@ -610,9 +611,13 @@ static int ovl_create_or_link(struct dentry *dentry, struct inode *inode, * create a new inode, so just use the ovl mounter's * fs{u,g}id. */ - err = ovl_setup_cred_for_create(dentry, inode, attr->mode, old_cred); - if (err) + new_cred = ovl_setup_cred_for_create(dentry, inode, attr->mode, + old_cred); + err = PTR_ERR(new_cred); + if (IS_ERR(new_cred)) { + new_cred = NULL; goto out_revert_creds; + } } if (!ovl_dentry_is_whiteout(dentry)) @@ -622,6 +627,7 @@ static int ovl_create_or_link(struct dentry *dentry, struct inode *inode, out_revert_creds: ovl_revert_creds(old_cred); + put_cred(new_cred); return err; } @@ -1306,7 +1312,7 @@ out: static int ovl_create_tmpfile(struct file *file, struct dentry *dentry, struct inode *inode, umode_t mode) { - const struct cred *old_cred; + const struct cred *old_cred, *new_cred = NULL; struct path realparentpath; struct file *realfile; struct dentry *newdentry; @@ -1315,9 +1321,12 @@ static int ovl_create_tmpfile(struct file *file, struct dentry *dentry, int err; old_cred = ovl_override_creds(dentry->d_sb); - err = ovl_setup_cred_for_create(dentry, inode, mode, old_cred); - if (err) + 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; + } ovl_path_upper(dentry->d_parent, &realparentpath); realfile = backing_tmpfile_open(&file->f_path, flags, &realparentpath, @@ -1338,6 +1347,7 @@ static int ovl_create_tmpfile(struct file *file, struct dentry *dentry, } out_revert_creds: ovl_revert_creds(old_cred); + put_cred(new_cred); return err; } |