From nobody Mon Feb 9 01:47:55 2026 Received: from ewsoutbound.kpnmail.nl (ewsoutbound.kpnmail.nl [195.121.94.167]) (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 9209E3B2A0 for ; Sun, 2 Nov 2025 18:25:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.121.94.167 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762107950; cv=none; b=mdnO//Y8KcQ6ic5kdlwE/beQl3Oyx1IsTkJ7FD6/06ntN+FGeybfS1znxCrA7E+Fv9cv1LJmW+DsUjNLxtyUgTr8zCLgiFOOuA0qir6/SXnxtSh2FTo5HWL67PtiOaHRCywWA8EaNbwBiYXksrbBZ+1uqvzRLyXwtx2TB2SxFUg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762107950; c=relaxed/simple; bh=TwHlJpZFsemf3UqLD8y60ujlqNUNm6ogZpd52yNfdYU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Mw8xaQM+Td37xy2b4BZu5CyfyQLPUv/AUO9ofo0uA7qYZoBUm/9Gtk2Z188Zl4qCLrl/is5baglrINPL/Cj/lv1hPd6w9gFC1XvVQZh/z+byMRgG3Ooujk6i01prhN8v0zgV4QcAgUAeFZeOFEZwKJMTmNgBKQPtwJ2uboCeJbc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=xs4all.nl; spf=pass smtp.mailfrom=xs4all.nl; dkim=pass (2048-bit key) header.d=xs4all.nl header.i=@xs4all.nl header.b=hqvy2c3r; arc=none smtp.client-ip=195.121.94.167 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=xs4all.nl Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xs4all.nl Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=xs4all.nl header.i=@xs4all.nl header.b="hqvy2c3r" X-KPN-MessageId: 9deae9ae-b819-11f0-a27d-005056abbe64 Received: from smtp.kpnmail.nl (unknown [10.31.155.39]) by ewsoutbound.so.kpn.org (Halon) with ESMTPS id 9deae9ae-b819-11f0-a27d-005056abbe64; Sun, 02 Nov 2025 19:27:41 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=xs4all.nl; s=xs4all01; h=mime-version:message-id:date:subject:to:from; bh=KjXwryYYJOl8pKhYag2MoDq8K98eIOWKWxcpjBWJmE8=; b=hqvy2c3rGUuSNYocAoJ2uK8OMM/WjmCMiPrJB6srMDRETV2WLoKv+mb3FEA/PizKVIMUnIfEx0JGA mK8UDidp43r77dfA0DsswDmIfBjcKOl7C5o+NFfSe6YPcqpJtMaVQzPxWtalBjEBTZcbC4CetbT2mw jBjtYodhAI1IRZm2aKbaU+ExgYCTB7oEqt+bWEyYEeF70jJ762ylVGwN3eP2gFg4G+D6UWcSba/DZq I6oCNjLEhmhFfefbDTlbacw9nPWJKA3oE5BiI2pWbTDzjhUKKiPh7FohuYJd9mliTd3mWVTD7n6Ya3 yUY//28t3L3SmTJgLDJ6orK1gbZQlxw== X-KPN-MID: 33|WBqdOdxHIk2PXkHzOI9dNj37wqZGkw5swjJuThHlmoU7qgPDwlHJ6UllP968jvC 5Kk1q7MXDq1dDgkqfa1mBgy5m1c6CD2LWLaxZfCLKnlc= X-KPN-VerifiedSender: Yes X-CMASSUN: 33|tHYjJi9VeW1esH8G21B3SpgmYURe7J00XQGgTl23hGEiXhttym9apfFPAEKvwYs W9w8Uc95WTEYlJfkC/yNJzA== Received: from daedalus.home (unknown [178.231.20.253]) by smtp.xs4all.nl (Halon) with ESMTPSA id 54f7d97a-b819-11f0-8005-005056ab7447; Sun, 02 Nov 2025 19:25:39 +0100 (CET) From: Jori Koolstra To: Christian Brauner , Tetsuo Handa , Taotao Chen , Jeff Layton , Jan Kara , NeilBrown Cc: jkoolstra@xs4all.nl, linux-kernel@vger.kernel.org, syzbot+a65e824272c5f741247d@syzkaller.appspotmail.com Subject: [PATCH] Fix a drop_nlink warning in minix_rename Date: Sun, 2 Nov 2025 19:25:32 +0100 Message-ID: <20251102182532.2442670-1-jkoolstra@xs4all.nl> X-Mailer: git-send-email 2.51.1.dirty 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" Syzbot found a drop_nlink warning that is triggered by an easy to detect nlink corruption. This patch adds sanity checks to minix_unlink and minix_rename to prevent the warning and instead return EFSCORRUPTED to the caller. The changes were tested using the syzbot reproducer as well as local testing. Signed-off-by: Jori Koolstra Reported-by: syzbot+a65e824272c5f741247d@syzkaller.appspotmail.com Closes: https://syzbot.org/bug?extid=3Da65e824272c5f741247d --- fs/minix/namei.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/fs/minix/namei.c b/fs/minix/namei.c index a8d5a7e22b7b..4bc1d9c31284 100644 --- a/fs/minix/namei.c +++ b/fs/minix/namei.c @@ -145,6 +145,12 @@ static int minix_unlink(struct inode * dir, struct den= try *dentry) struct minix_dir_entry * de; int err; =20 + if (inode->i_nlink < 1) { + printk(KERN_CRIT "minix-fs error: inode (ino: %ld) " + "has corrupted nlink", inode->i_ino); + return -EFSCORRUPTED; + } + de =3D minix_find_entry(dentry, &folio); if (!de) return -ENOENT; @@ -218,6 +224,13 @@ static int minix_rename(struct mnt_idmap *idmap, if (dir_de && !minix_empty_dir(new_inode)) goto out_dir; =20 + err =3D -EFSCORRUPTED; + if (new_inode->i_nlink =3D=3D 0 || (dir_de && new_inode->i_nlink !=3D 2)= ) { + printk(KERN_CRIT "minix-fs error: inode (ino: %ld) " + "has corrupted nlink", new_inode->i_ino); + goto out_dir; + } + err =3D -ENOENT; new_de =3D minix_find_entry(new_dentry, &new_folio); if (!new_de) --=20 2.51.1.dirty