From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EF4A0108E1FE for ; Thu, 19 Mar 2026 12:17:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 15A366B049D; Thu, 19 Mar 2026 08:17:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 10A016B049E; Thu, 19 Mar 2026 08:17:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 01F306B049F; Thu, 19 Mar 2026 08:17:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id E52B46B049D for ; Thu, 19 Mar 2026 08:17:14 -0400 (EDT) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 9C371C1EDD for ; Thu, 19 Mar 2026 12:17:14 +0000 (UTC) X-FDA: 84562712388.02.00D1B4B Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf05.hostedemail.com (Postfix) with ESMTP id 04DE210000B for ; Thu, 19 Mar 2026 12:17:12 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=keYiv5Gg; spf=pass (imf05.hostedemail.com: domain of broonie@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=broonie@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1773922633; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=emBGB9p5VsV2bWJ2GlBh0Rm15v/DEORykhqYZtuDxHE=; b=a1tUxQyyU7CRSkuZd2GkbAIkgiyTbTSMRNSEbHbk35TdTAvppAcWcJ475gS+8a0Kv570SU BlKnEJXzWeYtqSXKlfsewBkJroxWi72sg4TchnIF6yiQ7d43OjE/k/BFF2LhFUxzxEbxPc ZdxTAuxwyBH7xH4ThUqBWlopoCYroPo= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=keYiv5Gg; spf=pass (imf05.hostedemail.com: domain of broonie@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=broonie@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1773922633; a=rsa-sha256; cv=none; b=psDZoYiXjz8PreY1E9ZQ0ig19T1tihEAWEnei08MgATmZtpgGB56DH2k7l+YRhvY3R+4Er ulKwNP7eKazilSkgIAtfXdY0Oy3/XtVI5eJun9rdx2+/cLLmt38moiKXRg4z2RO7Yc6XaI fq1Pp4p+i8nOuKAKe9I4BwMw/CL34EM= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 6E136600AD; Thu, 19 Mar 2026 12:17:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 37652C19424; Thu, 19 Mar 2026 12:17:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773922632; bh=yDuN8W2IxSeMcfgbtfBkaW+G8+mALZNQqoWRx/nA/PQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=keYiv5GglJEbfYr2eGpLbX9Y+aslCrMg/8n0qHaCHjWPFAdCcdAsOygNGi7xbcQvi qRHBYLx6fohQd+zElGqnRy30rtvOIE3VOEUBHXVqi1cRoYZBg+QG9a0LaEAhNSCcEh SlD9vLOp7lUKpTQD7S3Ln1sHll1erEYwcnWbADzKVgk7ls0nxQqrbLm3TWypfsIvHs KneKsY2xR7Nk1B8VWsfgtzMgmRVwiqtAJavcNzZymrEF58e89/zp3uQpSGa8g+DZKl cjgRkl1z7leAPOiF9hq8BlaHNpjzLsSnp50tqp6qEcrrpvzHWzCl4ePMmwYS8mNYG1 cBebCs09pEShQ== Date: Thu, 19 Mar 2026 12:17:05 +0000 From: Mark Brown To: Vlastimil Babka Cc: Lance Yang , syzbot , david@kernel.org, ljs@kernel.org, willy@infradead.org, baolin.wang@linux.alibaba.com, npache@redhat.com, linux-mm@kvack.org, baohua@kernel.org, ryan.roberts@arm.com, syzkaller-bugs@googlegroups.com, dev.jain@arm.com, ziy@nvidia.com, linux-kernel@vger.kernel.org, Liam.Howlett@oracle.com, akpm@linux-foundation.org Subject: Re: [syzbot] [mm?] kernel BUG in collapse_scan_file Message-ID: <44cb1295-c2d4-4b94-a9d7-9ad369d0f2f2@sirena.org.uk> References: <69bba3c0.050a0220.227207.002b.GAE@google.com> <5eaa234e-76e5-45ec-833d-64d76903d1bf@suse.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="mR/c5f4Ns8MnS+yp" Content-Disposition: inline In-Reply-To: <5eaa234e-76e5-45ec-833d-64d76903d1bf@suse.com> X-Cookie: Given my druthers, I'd druther not. X-Stat-Signature: 7o6t56thk7js7wusnaahuz9yxqqfkgdf X-Rspamd-Server: rspam09 X-Rspam-User: X-Rspamd-Queue-Id: 04DE210000B X-HE-Tag: 1773922632-235960 X-HE-Meta: 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 Krp5h0Zr XSkYJsCQl+fXgAzf1XCjvAEyEfJ1HkSgD4LcVX3WIPpiuNe3PPawE3EuVCb0zvstp1g0sh0YeMtE0JA6aMkzIFp1z+/4aokfL38itKh989M1Cs+1igX8UrD4OWvOnHM71TYI02tOPqJ8eVkCHPf5QhM5ahrVmZRD0EIvd45DsCcw2/4GSAEYKKwmc3GK1WXSYA0b7PblRNDT7SAMnDezQfT/nE9OiSDew4/xIE4SQtXT0kKBPLNcOicIrgpdgZunPNAezQBI7Kc4emD6ORxKlSyEg2Y9YFECo0x8PXizvOmXcWMYzyw5YkKPcXao3kocWcgoAp6VW0eaFbxwuLc7NNMVI5CdFu6W/64IVh5hjI4G73ED9hbsxAUxrR0La+XZkja2Gs1o3P3Gv/g+Bv0XaRiU530nwoI5ers8uIg4hwdPSKM4JUfBIqqnT3UGNi0yR+Bjad0/LZILls5SSj6gJPray4hSeqgsQxamSAnCOBH00oySwEAxGlUcGak0WTHL2J9XQ8YCyPjPBaNZY64/+oOBM29+ZU1wKABrObZTus8EtGdiHpDJ+g+Ne5A== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: --mR/c5f4Ns8MnS+yp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Mar 19, 2026 at 11:56:21AM +0100, Vlastimil Babka wrote: > On 3/19/26 09:05, Lance Yang wrote: > > IIUC, this is a dup of the earlier report[1], which I looked into back > > in January. The root cause is the same: collapse_file() calls > > xas_lock_irq() without resetting the xas state first, tripping the > > XAS_INVALID() assertion: > >=20 > > #define xas_lock_irq(xas) xa_lock_irq(XAS_INVALID(xas)->xa) > >=20 > > static inline struct xa_state *XAS_INVALID(struct xa_state *xas) > > { > > XA_NODE_BUG_ON(xas->xa_node, xas_valid(xas)); > > return xas; > > } =2E.. > > I posted a HACK fix at the time[2], but David pointed out that Willy > > had mentioned it likely needs more thought[3]. =2E.. > That "needs more thought" was Jan 5. After 2.5 months later this is still > messing up linux-next testing due to a known unfixed problem. Completely > unnaceptable. Willy, you need to drop the new bug check until the known > problem is fixed. > Mark, please drop https://git.infradead.org/users/willy/xarray.git from > linux-next until it stops breaking linux-next. Thanks. I just saw this mail, I already started running the merge beforehand and don't 100% trust the scripts not to fall over if I make a change at this point - I can drop from tomorrow if things aren't sorted by then. I see the xarray tree hasn't been updated since before Christmas. --mR/c5f4Ns8MnS+yp Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmm76UAACgkQJNaLcl1U h9DvVQf/SfEDJuXK9yMz0xZ0P3v+CGLRi08+h9qxzkKqDofhZdRQufFv7rUa/W8r +Hc0bgaTeASHWTvmxKSRH00dial53xs6LcjKX+bsmv7wNasirCtm2sakhudTEgdy THmJprH5rISrlaP+msx1Az0qcQ6dsAUWrZyEMCeWZLG2ZmAcL2h0Ut/ILB8QLlYk ZYARhZSH5snLc16f44eJQ4nxXPteO2XoDnFg/SNRws+PPBT+iro2cBvuVP6QdW0Y fTJJY+a2eSKt6jXLKetpREEOCPOlJlJmGChJ7tvjzpBqmejS+PGuKVnk0BIfdFt0 Prs8DEO+uAdpY/akG6GZBz/5fi/GdA== =xXhS -----END PGP SIGNATURE----- --mR/c5f4Ns8MnS+yp--