From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail3-163.sinamail.sina.com.cn (mail3-163.sinamail.sina.com.cn [202.108.3.163]) (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 62A3921A928 for ; Thu, 17 Jul 2025 23:42:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.108.3.163 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752795755; cv=none; b=glGSi58yKVdcPCP/b8nXOOUw2tmEZX2mRL89skAPLj6dFy/x27i0N3PESqfYZ8vBUC6C0QbUccFVxrQcii1cRUBQofKVAS7RyABbEg+mW5UMz7Y2ZIj541EXDmFVPbH/FjYataDk9nNHFYNfYST2quRXU1GBA3XjaWaRgw0WBZs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752795755; c=relaxed/simple; bh=tLMeuWcY5dZ/SP2YIJD/jIA7A4PgzYheE3z+47KMQRI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UXzg0YvpG6lFFc5q1YAifYwu5k3IX4F0ivXhjd4VtbtPkBwsxb61jTofcXsaZw7K7j5LKBZ4VcPE1BBfgs+X1oTJn6vvLOUzQr0DPb/uj5aEewHcnRJPBJeO29C9m+4fYwh8aNvXJdjaRKeNcNNINY+vCa15aAdW0FssS8q2Fpk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b=NkbcIlH5; arc=none smtp.client-ip=202.108.3.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b="NkbcIlH5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sina.com; s=201208; t=1752795750; bh=0gdzAFi3nL1mlUMjX1WcxIl7a1Y3sVw0Mhg8EU6lFuQ=; h=From:Subject:Date:Message-ID; b=NkbcIlH5XMoQRyj58il5+8Z6+aHUmvQcpK+UcEXk/uW7ova3Cz6EISlfBXyPVAJOl pPsj+GrwlB8tZlwbpzxUNi1ea0H9Gjqh6JzWxkQ86FwMOh0CKMFN9s2MKqoOuxG5iq Do7LD5G/MfChq23b4GAE/8BA8YcHaI4kX4nQuHaY= X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([114.249.58.236]) by sina.com (10.54.253.34) with ESMTP id 68798A5C000060FC; Thu, 18 Jul 2025 07:42:21 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 091516291755 X-SMAIL-UIID: 730DF730D7E4429D9DCD6571EC87227F-20250718-074222-1 From: Hillf Danton To: Lorenzo Stoakes Cc: syzbot , akpm@linux-foundation.org, liam.howlett@oracle.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, vbabka@suse.cz Subject: Re: [syzbot] [mm?] KASAN: slab-use-after-free Read in mas_next_slot (2) Date: Fri, 18 Jul 2025 07:42:11 +0800 Message-ID: <20250717234212.2329-1-hdanton@sina.com> In-Reply-To: <4c29e030-4ba8-48e3-96bb-015d43768db0@lucifer.local> References: <20250717014623.2253-1-hdanton@sina.com> <68787417.a70a0220.693ce.0037.GAE@google.com> <8a2f1892-3184-4aaf-91ea-522e9ba2391b@lucifer.local> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Thu, 17 Jul 2025 17:06:34 +0100 Lorenzo Stoakes Top reply is not encouraged lad. > OK on second thoughts, there is one additional thing we need to do on each > loop to avoid observing the same VMA, either the prior logic of checking > directly or a vma_next(). > > So this may be a consequence of that. > > I will respin the series to make life easier... > Better after syzbot gives you Tested-by. > On Thu, Jul 17, 2025 at 05:18:17AM +0100, Lorenzo Stoakes wrote: > > This looks to be unrelated to my patch and some issue with syzbot (it's doing > > weird injection stuff). > > > > As I said, I have tested the change with reproducer locally and it fixes the > > issue, and I have been able to reliably observe that (note, without any of the > > below stuff happening). > > > > Thanks