From mboxrd@z Thu Jan 1 00:00:00 1970 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 45A522500A0; Sun, 24 Nov 2024 19:47:03 +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=1732477626; cv=none; b=PcAiw2+LQ7hD1/y/VhL85VmvIoQFpta53cFAqZGCB4wR0pIKCSGRG0ZAbTBf2HFv5FhfZPXtwTAukwD4gAvWl/p4u2+TwAfz5e8sdAKU3Wwps7ip7gU/Z+X6BJvitgc8v4Bc1Hj9ptVq7G8bm2jJm8fpM4H66+ocolpYz5Qs74A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732477626; c=relaxed/simple; bh=V+EtD5AFgjUn1Hh0hSk/ZUvhWf/V0hP09gwjOxmHp8A=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=L0ueUkf4F1625KlxRzXYyGb+PPxcdLBlw+9/Mb5hnfmGNe7YUsaZyiwUhYtsBImKBbq6LuFS90xNVwhTPCf5mDD0glXrFXCSA+bc3fvp4vLI7VN+BIoI8Yl33Z8/dxuekqyVBg1BwKU7dUXo6rHRLZIGxMaolAGoXfnxKnTHKzU= 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=cOrZ0QxI; 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="cOrZ0QxI" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=N8Ughgy84J+TxL5bBLTSQ7toDLa8snkul2Vje56+ZEA=; b=cOrZ0QxIscJxcejq6UnesPC3ZH OJygjFvte/VS+UbymsT1q0RCbgVtzHz91x7pJMuj2jPQpx1FkFK7eQuGGqVtY/X7ykS5ZDf+eG41C XBBav+Hz3NYYg+OO32mqc82uDmqu0hbCDw8JG8lAJGlO3rsD0mRQEGz+5lqx3ZgsSGltoTOOOBfhN QdPhVUe97ugMaQ/REHVmD/N5vud9PM5FGChGbgoN3CMeNwOKOTBXtmdsAVqT3FoYhj/BiHA6mKxId x+NxzH/qKtqllkXYU0LVLS6QIDIBKl+cK1SFZRr+kNdnrLCkeYvn1I+FZm2+U8lHNGE+GGjUFNQUU JyDwnC5w==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.98 #2 (Red Hat Linux)) id 1tFIZR-00000001IYK-3YAk; Sun, 24 Nov 2024 19:47:01 +0000 Date: Sun, 24 Nov 2024 19:47:01 +0000 From: Al Viro To: syzbot Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, surajsonawane0215@gmail.com, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [fs?] WARNING in minix_unlink Message-ID: <20241124194701.GY3387508@ZenIV> References: <6743814d.050a0220.1cc393.0049.GAE@google.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6743814d.050a0220.1cc393.0049.GAE@google.com> Sender: Al Viro On Sun, Nov 24, 2024 at 11:41:01AM -0800, syzbot wrote: > Hello, > > syzbot has tested the proposed patch but the reproducer is still triggering an issue: > WARNING in minix_unlink Predictably, since the warning has nothing to do with marking an unchanged buffer dirty... What happens there is that on a badly corrupt image we have an on-disk inode with link count below the actual number of links. And after unlinks remove enough of those to drive the link count to 0, inode is freed. After that point, all remaining links are pointing to a freed on-disk inode, which is discovered when they need to decrement of link count that is already 0. Which does deserve a warning, probably without a stack trace. There's nothing the kernel can do about that, short of scanning the entire filesystem at mount time and verifying that link counts are accurate...