From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3A87D389472; Mon, 13 Jul 2026 22:57:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783983443; cv=none; b=QQXHdAsZM4TDPZRQreXvQlHFsHpdEVUffhMU81WjNVDTKf+yYFcFAZURjtS1WwxMInKta1smcF4WXf/PUWHyYYXX4IkHLP734cTyUNY2mc1YSeAxbJ6pRFId1c0KVNM5FSdtnqFjTTqdVBw+tvaVRBLZwhrN/iH0jw02E4kk88o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783983443; c=relaxed/simple; bh=lAlbkyuFtk9eMY8meXRDlCOUUy9LoUu0C8gYdKsgKpw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DXCALMaUoX2ZKShH3TSUgULECzssFCz+7fjbSId0e7tVXLI8/pIRvyncFXCdQQWjFJ9NLJJpr1AyMkziDaDRT/oelHQKtZtC3MLQKKgehxjPrdd5vegHaWjLrOtKuf4ww9Uzt1EJWWhkLOMQnB5pkriCf+IsgHIEfeJVhTwlXg4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fBcWzFBI; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fBcWzFBI" Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id DA3821F000E9; Mon, 13 Jul 2026 22:57:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783983441; bh=gIY0Sz1b1fly6B4i18qKb2IWQRktJK8W9xo6mITWjgE=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=fBcWzFBIpFxRaH1CDVIv+IGL2Se4WfXqoagWgaue96FWv6wq4Mj+eHkhMcoImX2Hg 9y2OXZAZgP3g8gltsMHyOzo/DradtLxMR+AzYvCDi9YmYsabCleejmtyz6Rq+44kIQ TSJkXoVdmZsYj67VIzbwJMYNX6YvghLgr0VSZdFXuy5sBaOtX2V0GOmAjqxTnhq2H9 EMY33ZYb3XgDz5hMbkpBUqHt4pn4xqp4oXIornneXpUhATZykZUTKbU6NLEiroIcY7 YsuGuRcnoA++QP+EmFTXAiHQueQZepg17bxckc+YBmcSmkcB35JpgB2HwgbkbFDqWp XWOD1Xl8stwqQ== Date: Mon, 13 Jul 2026 15:57:21 -0700 From: "Darrick J. Wong" To: Xiang Mei Cc: Carlos Maiolino , linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, bestswngs@gmail.com Subject: Re: [PATCH] xfs: reject log continuation for a header-only item in recovery Message-ID: <20260713225721.GM7195@frogsfrogsfrogs> References: <20260712220854.3131445-1-xmei5@asu.edu> Precedence: bulk X-Mailing-List: linux-kernel@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: <20260712220854.3131445-1-xmei5@asu.edu> On Sun, Jul 12, 2026 at 03:08:54PM -0700, Xiang Mei wrote: > On an XLOG_WAS_CONT_TRANS op, xlog_recover_add_to_cont_trans() extends the > tail item's last region via item->ri_buf[item->ri_cnt-1] without checking > that the item has one. A header-only item, created by > xlog_recover_add_to_trans() when a transaction's first op is a bare > sizeof(struct xfs_trans_header) op carrying XFS_TRANS_HEADER_MAGIC, sits on > r_itemq with ri_cnt == 0 and ri_buf == NULL. A crafted log whose ops are > XLOG_START_TRANS, that header op, then XLOG_WAS_CONT_TRANS thus > dereferences ((struct kvec *)NULL)[-1] and faults during mount(2) log > recovery of an untrusted XFS image. > > A valid XLOG_WAS_CONT_TRANS only follows a region written with > XLOG_CONTINUE_TRANS, so ri_cnt >= 1 always holds for a real log. Reject the > ri_cnt == 0 case as corruption with -EFSCORRUPTED, which the caller already > propagates to abort recovery. > > BUG: unable to handle page fault for address: fffffffffffffff0 > #PF: supervisor read access in kernel mode > Oops: 0000 [#1] SMP KASAN NOPTI > RIP: 0010:xlog_recover_add_to_cont_trans (fs/xfs/xfs_log_recover.c:2135) > Call Trace: > xlog_recovery_process_trans (fs/xfs/xfs_log_recover.c:2306) > xlog_recover_process_data (fs/xfs/xfs_log_recover.c:2500) > xlog_do_recovery_pass (fs/xfs/xfs_log_recover.c:3243) > xlog_do_log_recovery (fs/xfs/xfs_log_recover.c:3331) > xlog_do_recover (fs/xfs/xfs_log_recover.c:3368) > xlog_recover (fs/xfs/xfs_log_recover.c:3493) > xfs_log_mount (fs/xfs/xfs_log.c:617) > xfs_mountfs (fs/xfs/xfs_mount.c:1031) > xfs_fs_fill_super (fs/xfs/xfs_super.c:1940) > get_tree_bdev_flags (fs/super.c:1634) > vfs_get_tree (fs/super.c:1694) > fc_mount (fs/namespace.c:1198) > path_mount (fs/namespace.c:4161) > __x64_sys_mount (fs/namespace.c:4367) > do_syscall_64 (arch/x86/entry/syscall_64.c:94) > entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) > Kernel panic - not syncing: Fatal exception > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Reported-by: Weiming Shi > Assisted-by: Claude:claude-opus-4-8 > Signed-off-by: Xiang Mei > --- > fs/xfs/xfs_log_recover.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c > index 5f984bf5698a..fa8e04bf1aac 100644 > --- a/fs/xfs/xfs_log_recover.c > +++ b/fs/xfs/xfs_log_recover.c > @@ -2131,6 +2131,9 @@ xlog_recover_add_to_cont_trans( > item = list_entry(trans->r_itemq.prev, struct xlog_recover_item, > ri_list); > > + if (item->ri_cnt == 0) > + return -EFSCORRUPTED; Didn't Weiming Shi already post a similar patch? Is this a duplicate, or a complement? --D > + > old_ptr = item->ri_buf[item->ri_cnt-1].iov_base; > old_len = item->ri_buf[item->ri_cnt-1].iov_len; > > -- > 2.43.0 > >