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BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-0.995]; MIME_GOOD(-0.10)[text/plain]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; MISSING_XM_UA(0.00)[]; TO_DN_SOME(0.00)[]; RCVD_TLS_ALL(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_FIVE(0.00)[5]; FROM_EQ_ENVFROM(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:email,imap1.dmz-prg2.suse.org:helo] X-Spam-Flag: NO X-Spam-Level: No callers of kern_path_locked() want a negative dentry. So change it to return -ENOENT instead. This simplifies callers. user_path_locked() needs to still return a negative dentry. The only caller of user_path_locked() wants a negative dentry so it can give the correct -EXDEV error when given a path on a different filesystem even when the final component of the path doesn't exist. Signed-off-by: NeilBrown --- This is an alternate version of 1/2 which doesn't change user_path_locked_at() or bcachefs. I'm only sending it to VFS emails and Kent. Please let me know if it is OK but you would rather I resent the whole series. Thanks, NeilBrown drivers/base/devtmpfs.c | 65 +++++++++++++++++++---------------------- fs/namei.c | 13 +++++++-- kernel/audit_watch.c | 12 ++++---- 3 files changed, 46 insertions(+), 44 deletions(-) diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c index b848764ef018..c9e34842139f 100644 --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -245,15 +245,12 @@ static int dev_rmdir(const char *name) dentry = kern_path_locked(name, &parent); if (IS_ERR(dentry)) return PTR_ERR(dentry); - if (d_really_is_positive(dentry)) { - if (d_inode(dentry)->i_private == &thread) - err = vfs_rmdir(&nop_mnt_idmap, d_inode(parent.dentry), - dentry); - else - err = -EPERM; - } else { - err = -ENOENT; - } + if (d_inode(dentry)->i_private == &thread) + err = vfs_rmdir(&nop_mnt_idmap, d_inode(parent.dentry), + dentry); + else + err = -EPERM; + dput(dentry); inode_unlock(d_inode(parent.dentry)); path_put(&parent); @@ -310,6 +307,8 @@ static int handle_remove(const char *nodename, struct device *dev) { struct path parent; struct dentry *dentry; + struct kstat stat; + struct path p; int deleted = 0; int err; @@ -317,32 +316,28 @@ static int handle_remove(const char *nodename, struct device *dev) if (IS_ERR(dentry)) return PTR_ERR(dentry); - if (d_really_is_positive(dentry)) { - struct kstat stat; - struct path p = {.mnt = parent.mnt, .dentry = dentry}; - err = vfs_getattr(&p, &stat, STATX_TYPE | STATX_MODE, - AT_STATX_SYNC_AS_STAT); - if (!err && dev_mynode(dev, d_inode(dentry), &stat)) { - struct iattr newattrs; - /* - * before unlinking this node, reset permissions - * of possible references like hardlinks - */ - newattrs.ia_uid = GLOBAL_ROOT_UID; - newattrs.ia_gid = GLOBAL_ROOT_GID; - newattrs.ia_mode = stat.mode & ~0777; - newattrs.ia_valid = - ATTR_UID|ATTR_GID|ATTR_MODE; - inode_lock(d_inode(dentry)); - notify_change(&nop_mnt_idmap, dentry, &newattrs, NULL); - inode_unlock(d_inode(dentry)); - err = vfs_unlink(&nop_mnt_idmap, d_inode(parent.dentry), - dentry, NULL); - if (!err || err == -ENOENT) - deleted = 1; - } - } else { - err = -ENOENT; + p.mnt = parent.mnt; + p.dentry = dentry; + err = vfs_getattr(&p, &stat, STATX_TYPE | STATX_MODE, + AT_STATX_SYNC_AS_STAT); + if (!err && dev_mynode(dev, d_inode(dentry), &stat)) { + struct iattr newattrs; + /* + * before unlinking this node, reset permissions + * of possible references like hardlinks + */ + newattrs.ia_uid = GLOBAL_ROOT_UID; + newattrs.ia_gid = GLOBAL_ROOT_GID; + newattrs.ia_mode = stat.mode & ~0777; + newattrs.ia_valid = + ATTR_UID|ATTR_GID|ATTR_MODE; + inode_lock(d_inode(dentry)); + notify_change(&nop_mnt_idmap, dentry, &newattrs, NULL); + inode_unlock(d_inode(dentry)); + err = vfs_unlink(&nop_mnt_idmap, d_inode(parent.dentry), + dentry, NULL); + if (!err || err == -ENOENT) + deleted = 1; } dput(dentry); inode_unlock(d_inode(parent.dentry)); diff --git a/fs/namei.c b/fs/namei.c index 3a4039acdb3f..e53427083342 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2721,7 +2721,8 @@ static int filename_parentat(int dfd, struct filename *name, } /* does lookup, returns the object with parent locked */ -static struct dentry *__kern_path_locked(int dfd, struct filename *name, struct path *path) +static struct dentry *__kern_path_locked(int dfd, struct filename *name, + struct path *path, bool require_positive) { struct dentry *d; struct qstr last; @@ -2736,6 +2737,10 @@ static struct dentry *__kern_path_locked(int dfd, struct filename *name, struct } inode_lock_nested(path->dentry->d_inode, I_MUTEX_PARENT); d = lookup_one_qstr_excl(&last, path->dentry, 0); + if (!IS_ERR(d) && d_is_negative(d) && !require_positive) { + dput(d); + d = ERR_PTR(-ENOENT); + } if (IS_ERR(d)) { inode_unlock(path->dentry->d_inode); path_put(path); @@ -2743,19 +2748,21 @@ static struct dentry *__kern_path_locked(int dfd, struct filename *name, struct return d; } +/* kern_path_locked() always returns a positive dentry or an error */ struct dentry *kern_path_locked(const char *name, struct path *path) { struct filename *filename = getname_kernel(name); - struct dentry *res = __kern_path_locked(AT_FDCWD, filename, path); + struct dentry *res = __kern_path_locked(AT_FDCWD, filename, path, true); putname(filename); return res; } +/* user_path_locks() may return a negative dentry */ struct dentry *user_path_locked_at(int dfd, const char __user *name, struct path *path) { struct filename *filename = getname(name); - struct dentry *res = __kern_path_locked(dfd, filename, path); + struct dentry *res = __kern_path_locked(dfd, filename, path, false); putname(filename); return res; diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c index 7f358740e958..e3130675ee6b 100644 --- a/kernel/audit_watch.c +++ b/kernel/audit_watch.c @@ -350,11 +350,10 @@ static int audit_get_nd(struct audit_watch *watch, struct path *parent) struct dentry *d = kern_path_locked(watch->path, parent); if (IS_ERR(d)) return PTR_ERR(d); - if (d_is_positive(d)) { - /* update watch filter fields */ - watch->dev = d->d_sb->s_dev; - watch->ino = d_backing_inode(d)->i_ino; - } + /* update watch filter fields */ + watch->dev = d->d_sb->s_dev; + watch->ino = d_backing_inode(d)->i_ino; + inode_unlock(d_backing_inode(parent->dentry)); dput(d); return 0; @@ -419,7 +418,7 @@ int audit_add_watch(struct audit_krule *krule, struct list_head **list) /* caller expects mutex locked */ mutex_lock(&audit_filter_mutex); - if (ret) { + if (ret && ret != -ENOENT) { audit_put_watch(watch); return ret; } @@ -438,6 +437,7 @@ int audit_add_watch(struct audit_krule *krule, struct list_head **list) h = audit_hash_ino((u32)watch->ino); *list = &audit_inode_hash[h]; + ret = 0; error: path_put(&parent_path); audit_put_watch(watch);