From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yx2-f3.google.com (mail-yx2-f3.google.com [74.125.224.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 660CE1A0B0E for ; Tue, 28 Jul 2026 23:57:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.224.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785283024; cv=none; b=IXPGqTm7ePYLgYv6MuSQsZhAvbLp2OVWb/RZV578MBqL2SAP0+TXYLNKXEYYQWFpNoh691p/bEq3Hp1CUjnisIkaArJ8wS3xUr+quGkuJ8Qt2M/YvtB4sLz77qxmqnOZYlRvnitN5O0H8g91VdpAeaW5VlXGIJ1N34POhdFLfHk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785283024; c=relaxed/simple; bh=8naspTudp50xj0goy0S849XPvZ79RoJ4z+jOViVzzAk=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=VlTqCX/x5ttibGVAYEXek7zw4fHKnb8gsT5/mVKA/yVxtTyHjvl9Glc02qHPDQe5JppJT9VcP+lvxnK3oHxh3jGce43wUCEsCoVgUl0jetEqKvpClNJ4sG/DtJwu1et5n2xYmKoPwRHCJjeIX4pvqQchQGO10ZOq/a7bd+/oNyQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=dubeyko.com; spf=pass smtp.mailfrom=dubeyko.com; dkim=pass (2048-bit key) header.d=dubeyko-com.20251104.gappssmtp.com header.i=@dubeyko-com.20251104.gappssmtp.com header.b=qqYEcBGv; arc=none smtp.client-ip=74.125.224.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=dubeyko.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=dubeyko.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=dubeyko-com.20251104.gappssmtp.com header.i=@dubeyko-com.20251104.gappssmtp.com header.b="qqYEcBGv" Received: by mail-yx2-f3.google.com with SMTP id 00721157ae682-81ea8feb828so3402017b3.1 for ; Tue, 28 Jul 2026 16:57:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dubeyko-com.20251104.gappssmtp.com; s=20251104; t=1785283021; x=1785887821; darn=vger.kernel.org; h=mime-version:user-agent:content-transfer-encoding:content-type :autocrypt:references:in-reply-to:date:cc:to:from:subject:message-id :from:to:cc:subject:date:message-id:reply-to:content-type; bh=32wKGwvjwqfLOfIf5NfxbpKtE655uaW4tNdfVjx28Qk=; b=qqYEcBGv5sLus500zX2AnDTuQvmhPkqtOLdzytbL7x3JyF0xBFoLg9pBXbP5rrlUfr 3NhHP0w+qJM143AlUOINbm6tabe1yIwsMNVZ5x+Cukow2YNg/uO8V/REMquCpeW43YEs +FlOucPGCnu0HuAJKPbvYXKjJW2Ipkqq54t3QIwK4+mNA5GCsnjmNoGUyfo9+PWHg9nP X/EnaDRox3KJ9n6RlJRu3EmM//dyVIVC2A4A8bRaDIbnl7wd7bWPPfRfp7RQErLdv1kW aiKNneIrp4xvYlAZyVsSv5UbxX57+UxU7aUFGW+IRrt9MHch+xNj21fuQwcxnXzdA4FT Qmzg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785283021; x=1785887821; h=mime-version:user-agent:content-transfer-encoding:content-type :autocrypt:references:in-reply-to:date:cc:to:from:subject:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=32wKGwvjwqfLOfIf5NfxbpKtE655uaW4tNdfVjx28Qk=; b=Djrh0I/C0EvKG9/M5gC0KbVyxbXcfwZiCweZhMKkqTvlVx6PEAdhnAFstc0Qf8VF3S YZ0/nGxZmAougEdiQrpP/7P40KwfT/vcvoDyWfpn1sOkcqliSd4FmPoCXInsN0OdIVVz /YSrodKms/VUFrIAfqGCIL0UVeCkG/2Yc1JBrgLozXk40ggD0afj8tCscp1xHK8QNi9U BAkDpNNQv6l83r7fv/OcNPB/aCEm2b+CAnF4wIk2hk7DnsHvFlfGBFD0Cp3sOzXmVWty wOVZzZqUEKlwArTzJXq6ga7+jP23WwubuKeTn1ieALbKLLk1+EI3E0+apWVgI5g+X44t eYrQ== X-Forwarded-Encrypted: i=1; AHgh+RoSOUeZTQ7E8mOc4/zCxO17OExMBL4Oe4mv0M47QzRp7S/nlqvl4yimtLQ2WA61Fdqgu4+ZRnFT386t1ro=@vger.kernel.org X-Gm-Message-State: AOJu0Yxylk9Jdh/jjeIfO74LX9kTHPZ4jzKu95uo0p6N8P/QjMIMByH6 8rGK0r1TvVZEJRbEPcmryX1YAPtIbv8NfSrfa/C845gsIwqOHJgyrVgxDFdl+iddFbg= X-Gm-Gg: AR+sD126tNpwCEtbViDf/ENEguNjRb0vMgU8T4LjJtGSoR07s15YwFNH4cRv0U3dG7B RdG7pmFBRfkx9VppKVzwndBm0lgHoIs0AuFA5kISxnDIsom1NscACaKD2gPTao7v1O4gGB4821q ksqklx2dqAzTOirBCgMqcVvASbPJAF6oh5HOA0ZGtJP05onVub4obp5vse7T9p1QMaTfoliZyV7 BKV8iN2nbVYnyFpg5s4fWKyQ56coO/ZIWv/2q5Dn7EI56MVjfuA3E+4/XwA+T7a/3XTJzIKfJD7 eQmJ2SJw7Bos9JlEBkrCVGSSBTfKfiMJ5Ae2/0aZmYJeiXb4kaHwUrsyCoBk06gCEn3CRQUZFHV 3uVSZd+WKi2papbke8nxphPbNa/qKtDwnN3T9LkFhWiG8YB0a9j9nDe8Soh8fVq+wgi/GXTJa+k 7ISB6jlQZUGZIQhYepsw0bKLN9eaCbLsEAdfoUWIBurcseg+adKF+evNLEZS8s5LC64V1ZK/HCs khS00Cun4G481LZw+QSxbg5EPBUMQ/CEVftVmgRyiV+1JI/Mrl1Lvu6qKnZJqW4d6/FlSuR8D6e n6CJnnvdF2CRyxBSsuowuRtCwt6/zUlU/10upm67y2AZN7TgyYlSj9U= X-Received: by 2002:a05:690c:3681:b0:81e:d8ec:d855 with SMTP id 00721157ae682-81f9936c55dmr20768427b3.62.1785283021318; Tue, 28 Jul 2026 16:57:01 -0700 (PDT) Received: from [10.0.0.3] (162-197-212-70.lightspeed.sntcca.sbcglobal.net. [162.197.212.70]) by smtp.gmail.com with ESMTPSA id 00721157ae682-81fa27592e9sm8541417b3.8.2026.07.28.16.57.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jul 2026 16:57:00 -0700 (PDT) Message-ID: <66ad542bb23dbc1798b7c69f7912bf86cb79c8f7.camel@dubeyko.com> Subject: Re: [PATCH] nilfs2: fix BUG in nilfs_copy_dirty_pages() on dirty state mismatch From: Viacheslav Dubeyko To: Ryusuke Konishi Cc: linux-nilfs , LKML , syzbot+8baf9a79a3ffc6271cb6@syzkaller.appspotmail.com, syzkaller-bugs@googlegroups.com Date: Tue, 28 Jul 2026 16:56:59 -0700 In-Reply-To: <20260720141716.205384-1-konishi.ryusuke@gmail.com> References: <20260720141716.205384-1-konishi.ryusuke@gmail.com> Autocrypt: addr=slava@dubeyko.com; prefer-encrypt=mutual; keydata=mQINBGgaTLYBEADaJc/WqWTeunGetXyyGJ5Za7b23M/ozuDCWCp+yWUa2GqQKH40dxRIR zshgOmAue7t9RQJU9lxZ4ZHWbi1Hzz85+0omefEdAKFmxTO6+CYV0g/sapU0wPJws3sC2Pbda9/eJ ZcvScAX2n/PlhpTnzJKf3JkHh3nM1ACO3jzSe2/muSQJvqMLG2D71ccekr1RyUh8V+OZdrPtfkDam V6GOT6IvyE+d+55fzmo20nJKecvbyvdikWwZvjjCENsG9qOf3TcCJ9DDYwjyYe1To8b+mQM9nHcxp jUsUuH074BhISFwt99/htZdSgp4csiGeXr8f9BEotRB6+kjMBHaiJ6B7BIlDmlffyR4f3oR/5hxgy dvIxMocqyc03xVyM6tA4ZrshKkwDgZIFEKkx37ec22ZJczNwGywKQW2TGXUTZVbdooiG4tXbRBLxe ga/NTZ52ZdEkSxAUGw/l0y0InTtdDIWvfUT+WXtQcEPRBE6HHhoeFehLzWL/o7w5Hog+0hXhNjqte fzKpI2fWmYzoIb6ueNmE/8sP9fWXo6Av9m8B5hRvF/hVWfEysr/2LSqN+xjt9NEbg8WNRMLy/Y0MS p5fgf9pmGF78waFiBvgZIQNuQnHrM+0BmYOhR0JKoHjt7r5wLyNiKFc8b7xXndyCDYfniO3ljbr0j tXWRGxx4to6FwARAQABtCZWaWFjaGVzbGF2IER1YmV5a28gPHNsYXZhQGR1YmV5a28uY29tPokCVw QTAQoAQQIbAQUJA8JnAAULCQgHAgYVCgkICwIEFgIDAQIeAQIXgBYhBFXDC2tnzsoLQtrbBDlc2cL fhEB1BQJoGl5PAhkBAAoJEDlc2cLfhEB17DsP/jy/Dx19MtxWOniPqpQf2s65enkDZuMIQ94jSg7B F2qTKIbNR9SmsczjyjC+/J7m7WZRmcqnwFYMOyNfh12aF2WhjT7p5xEAbvfGVYwUpUrg/lcacdT0D Yk61GGc5ZB89OAWHLr0FJjI54bd7kn7E/JRQF4dqNsxU8qcPXQ0wLHxTHUPZu/w5Zu/cO+lQ3H0Pj pSEGaTAh+tBYGSvQ4YPYBcV8+qjTxzeNwkw4ARza8EjTwWKP2jWAfA/ay4VobRfqNQ2zLoo84qDtN Uxe0zPE2wobIXELWkbuW/6hoQFPpMlJWz+mbvVms57NAA1HO8F5c1SLFaJ6dN0AQbxrHi45/cQXla 9hSEOJjxcEnJG/ZmcomYHFneM9K1p1K6HcGajiY2BFWkVet9vuHygkLWXVYZ0lr1paLFR52S7T+cf 6dkxOqu1ZiRegvFoyzBUzlLh/elgp3tWUfG2VmJD3lGpB3m5ZhwQ3rFpK8A7cKzgKjwPp61Me0o9z HX53THoG+QG+o0nnIKK7M8+coToTSyznYoq9C3eKeM/J97x9+h9tbizaeUQvWzQOgG8myUJ5u5Dr4 6tv9KXrOJy0iy/dcyreMYV5lwODaFfOeA4Lbnn5vRn9OjuMg1PFhCi3yMI4lA4umXFw0V2/OI5rgW BQELhfvW6mxkihkl6KLZX8m1zcHitCpWaWFjaGVzbGF2IER1YmV5a28gPFNsYXZhLkR1YmV5a29Aa WJtLmNvbT6JAlQEEwEKAD4WIQRVwwtrZ87KC0La2wQ5XNnC34RAdQUCaBpd7AIbAQUJA8JnAAULCQ gHAgYVCgkICwIEFgIDAQIeAQIXgAAKCRA5XNnC34RAdYjFEACiWBEybMt1xjRbEgaZ3UP5i2bSway DwYDvgWW5EbRP7JcqOcZ2vkJwrK3gsqC3FKpjOPh7ecE0I4vrabH1Qobe2N8B2Y396z24mGnkTBbb 16Uz3PC93nFN1BA0wuOjlr1/oOTy5gBY563vybhnXPfSEUcXRd28jI7z8tRyzXh2tL8ZLdv1u4vQ8 E0O7lVJ55p9yGxbwgb5vXU4T2irqRKLxRvU80rZIXoEM7zLf5r7RaRxgwjTKdu6rYMUOfoyEQQZTD 4Xg9YE/X8pZzcbYFs4IlscyK6cXU0pjwr2ssjearOLLDJ7ygvfOiOuCZL+6zHRunLwq2JH/RmwuLV mWWSbgosZD6c5+wu6DxV15y7zZaR3NFPOR5ErpCFUorKzBO1nA4dwOAbNym9OGkhRgLAyxwpea0V0 ZlStfp0kfVaSZYo7PXd8Bbtyjali0niBjPpEVZdgtVUpBlPr97jBYZ+L5GF3hd6WJFbEYgj+5Af7C UjbX9DHweGQ/tdXWRnJHRzorxzjOS3003ddRnPtQDDN3Z/XzdAZwQAs0RqqXrTeeJrLppFUbAP+HZ TyOLVJcAAlVQROoq8PbM3ZKIaOygjj6Yw0emJi1D9OsN2UKjoe4W185vamFWX4Ba41jmCPrYJWAWH fAMjjkInIPg7RLGs8FiwxfcpkILP0YbVWHiNAabQoVmlhY2hlc2xhdiBEdWJleWtvIDx2ZHViZXlr b0BrZXJuZWwub3JnPokCVAQTAQoAPhYhBFXDC2tnzsoLQtrbBDlc2cLfhEB1BQJoVemuAhsBBQkDw mcABQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAAAoJEDlc2cLfhEB1GRwP/1scX5HO9Sk7dRicLD/fxo ipwEs+UbeA0/TM8OQfdRI4C/tFBYbQCR7lD05dfq8VsYLEyrgeLqP/iRhabLky8LTaEdwoAqPDc/O 9HRffx/faJZqkKc1dZryjqS6b8NExhKOVWmDqN357+Cl/H4hT9wnvjCj1YEqXIxSd/2Pc8+yw/KRC AP7jtRzXHcc/49Lpz/NU5irScusxy2GLKa5o/13jFK3F1fWX1wsOJF8NlTx3rLtBy4GWHITwkBmu8 zI4qcJGp7eudI0l4xmIKKQWanEhVdzBm5UnfyLIa7gQ2T48UbxJlWnMhLxMPrxgtC4Kos1G3zovEy Ep+fJN7D1pwN9aR36jVKvRsX7V4leIDWGzCdfw1FGWkMUfrRwgIl6i3wgqcCP6r9YSWVQYXdmwdMu 1RFLC44iF9340S0hw9+30yGP8TWwd1mm8V/+zsdDAFAoAwisi5QLLkQnEsJSgLzJ9daAsE8KjMthv hUWHdpiUSjyCpigT+KPl9YunZhyrC1jZXERCDPCQVYgaPt+Xbhdjcem/ykv8UVIDAGVXjuk4OW8la nf8SP+uxkTTDKcPHOa5rYRaeNj7T/NClRSd4z6aV3F6pKEJnEGvv/DFMXtSHlbylhyiGKN2Amd0b4 9jg+DW85oNN7q2UYzYuPwkHsFFq5iyF1QggiwYYTpoVXsw Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.60.1 (by Flathub.org) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Mon, 2026-07-20 at 23:16 +0900, Ryusuke Konishi wrote: > Syzbot reported a kernel BUG triggered within > nilfs_copy_dirty_pages(), > which copies dirty DAT file folios/pages to its shadow page cache.=C2=A0 > The > BUG occurs when a retrieved dirty folio/page unexpectedly loses its > 'dirty' status. >=20 > This issue arises because, since the commit referenced below, the > 'dirty' > flag of a folio/page can be cleared asynchronously after the > filesystem > detects metadata corruption and transitions to read-only mode. >=20 > Resolve the issue by returning an -EROFS error if the filesystem has > transitioned to read-only mode.=C2=A0 Also change the behavior to issue a > kernel warning only once instead of triggering a kernel BUG when this > unexpected 'dirty' state is detected while the filesystem is not in > read-only mode. >=20 > Reported-by: syzbot+8baf9a79a3ffc6271cb6@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=3D8baf9a79a3ffc6271cb6 > Fixes: 8c26c4e2694a ("nilfs2: fix issue with flush kernel thread > after remount in RO mode because of driver's internal error or > metadata corruption") > Signed-off-by: Ryusuke Konishi > --- > Viacheslav, please apply this for the next cycle. >=20 > This fixes an issue reported by syzbot where a kernel BUG could be > triggered depending on timing after filesystem corruption is > detected. >=20 > Thanks, > Ryusuke Konishi >=20 > =C2=A0fs/nilfs2/page.c | 17 +++++++++++++++-- > =C2=A01 file changed, 15 insertions(+), 2 deletions(-) >=20 > diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c > index a9d8aa65416f..1d00bce21c37 100644 > --- a/fs/nilfs2/page.c > +++ b/fs/nilfs2/page.c > @@ -243,6 +243,7 @@ static void nilfs_copy_folio(struct folio *dst, > struct folio *src, > =C2=A0int nilfs_copy_dirty_pages(struct address_space *dmap, > =C2=A0 =C2=A0=C2=A0 struct address_space *smap) > =C2=A0{ > + struct inode *smap_inode =3D smap->host; > =C2=A0 struct folio_batch fbatch; > =C2=A0 unsigned int i; > =C2=A0 pgoff_t index =3D 0; > @@ -258,8 +259,19 @@ int nilfs_copy_dirty_pages(struct address_space > *dmap, > =C2=A0 struct folio *folio =3D fbatch.folios[i], *dfolio; > =C2=A0 > =C2=A0 folio_lock(folio); > - if (unlikely(!folio_test_dirty(folio))) > - NILFS_FOLIO_BUG(folio, "inconsistent dirty > state"); > + if (unlikely(!folio_test_dirty(folio))) { > + if (WARN_ONCE(!sb_rdonly(smap_inode->i_sb), > + "inconsistent dirty > state\n")) > + goto unlock_folio; > + > + /* > + * If the filesystem has been forced to > read-only > + * due to metadata corruption. > + */ > + folio_unlock(folio); > + err =3D -EROFS; > + break; > + } > =C2=A0 > =C2=A0 dfolio =3D filemap_grab_folio(dmap, folio->index); > =C2=A0 if (IS_ERR(dfolio)) { > @@ -277,6 +289,7 @@ int nilfs_copy_dirty_pages(struct address_space > *dmap, > =C2=A0 > =C2=A0 folio_unlock(dfolio); > =C2=A0 folio_put(dfolio); > +unlock_folio: > =C2=A0 folio_unlock(folio); > =C2=A0 } > =C2=A0 folio_batch_release(&fbatch); Applied. Thanks, Slava.