Commit 49246466a989 ("fsnotify: move fsnotify_nameremove() hook out of
d_delete()") moved the fsnotify delete hook before d_delete() so fsnotify
will have access to a positive dentry.
This allowed a race where opening the deleted file via cached dentry
is now possible after receiving the IN_DELETE event.
To fix the regression in pseudo filesystems, convert d_delete() calls
to d_drop() (see commit 46c46f8df9aa ("devpts_pty_kill(): don't bother
with d_delete()") and move the fsnotify hook after d_drop().
Add a missing fsnotify_unlink() hook in nfsdfs that was found during
the audit of fsnotify hooks in pseudo filesystems.
Note that the fsnotify hooks in simple_recursive_removal() follow
d_invalidate(), so they require no change.
Reported-by: Ivan Delalande <colona@xxxxxxxxxx>
Link: https://lore.kernel.org/linux-fsdevel/YeNyzoDM5hP5LtGW@visor/
Fixes: 49246466a989 ("fsnotify: move fsnotify_nameremove() hook out of d_delete()")
Cc: stable@xxxxxxxxxxxxxxx # v5.3+
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
fs/configfs/dir.c | 6 +++---
fs/devpts/inode.c | 2 +-
fs/nfsd/nfsctl.c | 5 +++--
net/sunrpc/rpc_pipe.c | 4 ++--
4 files changed, 9 insertions(+), 8 deletions(-)
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 1466b5d01cbb..d3cd2a94d1e8 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -1780,8 +1780,8 @@ void configfs_unregister_group(struct config_group *group)
configfs_detach_group(&group->cg_item);
d_inode(dentry)->i_flags |= S_DEAD;
dont_mount(dentry);
+ d_drop(dentry);
fsnotify_rmdir(d_inode(parent), dentry);
- d_delete(dentry);
inode_unlock(d_inode(parent));
dput(dentry);
@@ -1922,10 +1922,10 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
configfs_detach_group(&group->cg_item);
d_inode(dentry)->i_flags |= S_DEAD;
dont_mount(dentry);
- fsnotify_rmdir(d_inode(root), dentry);
inode_unlock(d_inode(dentry));
- d_delete(dentry);
+ d_drop(dentry);
+ fsnotify_rmdir(d_inode(root), dentry);
inode_unlock(d_inode(root));
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index 42e5a766d33c..4f25015aa534 100644
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -621,8 +621,8 @@ void devpts_pty_kill(struct dentry *dentry)
dentry->d_fsdata = NULL;
drop_nlink(dentry->d_inode);
- fsnotify_unlink(d_inode(dentry->d_parent), dentry);
d_drop(dentry);
+ fsnotify_unlink(d_inode(dentry->d_parent), dentry);
dput(dentry); /* d_alloc_name() in devpts_pty_new() */
}
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 51a49e0cfe37..d0761ca8cb54 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -1249,7 +1249,8 @@ static void nfsdfs_remove_file(struct inode *dir, struct dentry *dentry)
clear_ncl(d_inode(dentry));
dget(dentry);
ret = simple_unlink(dir, dentry);
- d_delete(dentry);
+ d_drop(dentry);
+ fsnotify_unlink(dir, dentry);
dput(dentry);
WARN_ON_ONCE(ret);
}
@@ -1340,8 +1341,8 @@ void nfsd_client_rmdir(struct dentry *dentry)
dget(dentry);
ret = simple_rmdir(dir, dentry);
WARN_ON_ONCE(ret);
+ d_drop(dentry);
fsnotify_rmdir(dir, dentry);
- d_delete(dentry);
dput(dentry);
inode_unlock(dir);
}
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index ee5336d73fdd..35588f0afa86 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -600,9 +600,9 @@ static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
dget(dentry);
ret = simple_rmdir(dir, dentry);
+ d_drop(dentry);
if (!ret)
fsnotify_rmdir(dir, dentry);
- d_delete(dentry);
dput(dentry);
return ret;
}
@@ -613,9 +613,9 @@ static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
dget(dentry);
ret = simple_unlink(dir, dentry);
+ d_drop(dentry);
if (!ret)
fsnotify_unlink(dir, dentry);
- d_delete(dentry);
dput(dentry);
return ret;
}
--
2.34.1
