From patchwork Sun Feb 4 02:17:27 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Al Viro X-Patchwork-Id: 13544406 Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ACBBC6FA8; Sun, 4 Feb 2024 02:17:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.89.141.173 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707013064; cv=none; b=mCkDyvVh3RmGzDwoVrJzY0dWQ678j9YRE/LTuqWysCDw6flnnu8rJb+LyfTV5YkoL8K/WZSBiFIh06UHotNJn3El71bkyU9nF6W97CeMMeUa42zePgI+yNebWAhiK1Yabzc+ydM7glJ2uLK20xpvoa2R2y35HTvXj2g+yX9V2lk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707013064; c=relaxed/simple; bh=j6rsvNN8oo5Bvj0EJ/yVmFHfs8Um7QkVVzBq0K42Rqw=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=cPgtVnBcKCWxjXzi7+XVXHH0zFHCgwZ+zZKo749MYFARMsaH2v/qnNpx4PCaCQ50yS1KZflORTm8Eg9ahQvuxVTW0VU1xYBIwI89aVhj5p5N+ig5oTtviOnxt1Vg8NXrH9mB+0cIcojiOaMGn7766pRFg/OPDElmY0cFCWv34pQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk; spf=none smtp.mailfrom=ftp.linux.org.uk; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b=BfiaI6RP; arc=none smtp.client-ip=62.89.141.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=ftp.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b="BfiaI6RP" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=1HFI4KKL79Sd/NlR6QYbK/LO3YNDNZj8ruRJ2Po8n78=; b=BfiaI6RPnXysexAqLOvzi/xd4/ xNQPKqHFXPKgXHMATcWLBhPpjAX2hBrdsZ4f2kv8pFN9qnEXeVAY/T/0zHISphhPHGp983TaopYhX JiEhRug4uAeivhZ62q8RBH8BwurRmaVlNA1rrxGt8VaXyN1F6MeVAYVwVaU2/Ficj/n1MLKSqBm8K koW3ZUCW855MWUF1bfbFJBFasSiwUaGxg4mXy5aTcN9Woh5mqF0sOTyPKg3TEC3/QJx4HsDKAe90F Tp1hdtHYVWhp05Uq7XiM2VqM0KEfl6fQwDbgJmGRk5d0g0ZKc2lEjYLtjlvY+eZSGgv/puzMo0UXt NvAu0mpw==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.96 #2 (Red Hat Linux)) id 1rWS4h-004rCn-2m; Sun, 04 Feb 2024 02:17:40 +0000 From: Al Viro To: linux-fsdevel@vger.kernel.org Cc: Linus Torvalds , Christian Brauner , linux-ext4@vger.kernel.org, linux-nfs@vger.kernel.org, Miklos Szeredi , linux-cifs@vger.kernel.org Subject: [PATCH 01/13] fs/super.c: don't drop ->s_user_ns until we free struct super_block itself Date: Sun, 4 Feb 2024 02:17:27 +0000 Message-Id: <20240204021739.1157830-1-viro@zeniv.linux.org.uk> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240204021436.GH2087318@ZenIV> References: <20240204021436.GH2087318@ZenIV> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Sender: Al Viro Avoids fun races in RCU pathwalk... Same goes for freeing LSM shite hanging off super_block's arse. Signed-off-by: Al Viro Reviewed-by: Christian Brauner Reviewed-by: Jeff Layton --- fs/super.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/fs/super.c b/fs/super.c index d35e85295489..d6efeba0d0ce 100644 --- a/fs/super.c +++ b/fs/super.c @@ -274,9 +274,10 @@ static void destroy_super_work(struct work_struct *work) { struct super_block *s = container_of(work, struct super_block, destroy_work); - int i; - - for (i = 0; i < SB_FREEZE_LEVELS; i++) + security_sb_free(s); + put_user_ns(s->s_user_ns); + kfree(s->s_subtype); + for (int i = 0; i < SB_FREEZE_LEVELS; i++) percpu_free_rwsem(&s->s_writers.rw_sem[i]); kfree(s); } @@ -296,9 +297,6 @@ static void destroy_unused_super(struct super_block *s) super_unlock_excl(s); list_lru_destroy(&s->s_dentry_lru); list_lru_destroy(&s->s_inode_lru); - security_sb_free(s); - put_user_ns(s->s_user_ns); - kfree(s->s_subtype); shrinker_free(s->s_shrink); /* no delays needed */ destroy_super_work(&s->destroy_work); @@ -409,9 +407,6 @@ static void __put_super(struct super_block *s) WARN_ON(s->s_dentry_lru.node); WARN_ON(s->s_inode_lru.node); WARN_ON(!list_empty(&s->s_mounts)); - security_sb_free(s); - put_user_ns(s->s_user_ns); - kfree(s->s_subtype); call_rcu(&s->rcu, destroy_super_rcu); } }