From nobody Sun Feb 8 16:50:13 2026 Received: from air.basealt.ru (air.basealt.ru [193.43.8.18]) (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 9A1B938F91 for ; Tue, 24 Dec 2024 14:55:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.43.8.18 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735052106; cv=none; b=fm1L2N89FUT0Hnkh/uj7NIpzvh/6I14yq4MAOrTmjtkF39oL6erBtXsQPD6HCLQMczOEPAqIyYASrGmcRAe/kIfKtzPbkx3yUm/i2jqSUojgohXdwMsuOniBf3ofdFmcVGpx+41Ry6t/wZvIwRrHdvCcEJkj3Lf7l8imzzJT9NE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735052106; c=relaxed/simple; bh=CBYXLkNd12+jvfnIlbEUOdPG952WG7cnTmWtLmst6W4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=GfhHoS93y+ewlVtX4JZfWMWfo4+NuxcFxklhIkRoxaHwUzYF8l7xUJBQ6Q3r7V3rF0j7QhiCudi8W1GZp7zib1u1A4SoYQ5VEx8/bkZE9HOeAr5rXhpCXXvqkgq9NapamQOBd4ddkEhCAaSRmKYf2IvHW6duONXboH5FsJ9zNoc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=altlinux.org; spf=pass smtp.mailfrom=altlinux.org; arc=none smtp.client-ip=193.43.8.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=altlinux.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=altlinux.org Received: from altlinux.ipa.basealt.ru (unknown [178.76.204.78]) by air.basealt.ru (Postfix) with ESMTPSA id 9A035233B5; Tue, 24 Dec 2024 17:49:29 +0300 (MSK) From: Vasiliy Kovalev To: Dave Kleikamp , Josef Bacik , Matthew Wilcox , Christian Brauner , jfs-discussion@lists.sourceforge.net, linux-kernel@vger.kernel.org Cc: lvc-project@linuxtesting.org, kovalev@altlinux.org, syzbot+4e89b5368baba8324e07@syzkaller.appspotmail.com Subject: [PATCH 2/2] jfs: add check read-only before truncation in jfs_truncate_nolock() Date: Tue, 24 Dec 2024 17:49:14 +0300 Message-Id: <20241224144914.976419-3-kovalev@altlinux.org> X-Mailer: git-send-email 2.33.8 In-Reply-To: <20241224144914.976419-1-kovalev@altlinux.org> References: <20241224144914.976419-1-kovalev@altlinux.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Added a check for "read-only" mode in the `jfs_truncate_nolock` function to avoid errors related to writing to a read-only filesystem. Call stack: block_write_begin() { jfs_write_failed() { jfs_truncate() { jfs_truncate_nolock() { txEnd() { ... log =3D JFS_SBI(tblk->sb)->log; // (log =3D=3D NULL) If the `isReadOnly(ip)` condition is triggered in `jfs_truncate_nolock`, the function execution will stop, and no further data modification will occur. Instead, the `xtTruncate` function will be called with the "COMMIT_WMAP" flag, preventing modifications in "read-only" mode. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+4e89b5368baba8324e07@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=3D4e89b5368baba8324e07 Signed-off-by: Vasiliy Kovalev --- fs/jfs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c index 07cfdc4405968b..60fc92dee24d20 100644 --- a/fs/jfs/inode.c +++ b/fs/jfs/inode.c @@ -369,7 +369,7 @@ void jfs_truncate_nolock(struct inode *ip, loff_t lengt= h) =20 ASSERT(length >=3D 0); =20 - if (test_cflag(COMMIT_Nolink, ip)) { + if (test_cflag(COMMIT_Nolink, ip) || isReadOnly(ip)) { xtTruncate(0, ip, length, COMMIT_WMAP); return; } --=20 2.33.8