From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f70.google.com (mail-ot1-f70.google.com [209.85.210.70]) (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 B68C33B5307 for ; Fri, 17 Apr 2026 10:12:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776420762; cv=none; b=c0akgn7q+0AiZXbEg2IitAczfqeXxAQMuSaKRhl56ZC+lxgzsi5hPk7eyhXTafA2o+MLcirblD22aMXdEPrH9tqvgPFU6eoRkbIkVvfSAc4A8x8QCOdNbAQ/yI/y8JuU/+7w781fD9XX/VNjYn9M7Z1mfXi6Usi+8arOUhEElds= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776420762; c=relaxed/simple; bh=EmKjoCVaY4M6HeEndZYV193QpWr/xiKv5DVMEMPXV4s=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=qOT+RnwDlcopA9oyFlYSANJS1FjacyWaWa0bu3w35l502zh3QUlMTLLS3DkuQUXlNd41fEORcRq8nj97j3ywsU1NXvEsV+kxTlU9nBk9m/Lk2MKZ28j946TK8KIxClIUcCSvmemOfNW6dZAMjp7+FRbjhOfW1LzlpdPOzx71ZOc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.210.70 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-ot1-f70.google.com with SMTP id 46e09a7af769-7d7fd0be5e3so3085262a34.0 for ; Fri, 17 Apr 2026 03:12:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776420760; x=1777025560; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=XyitjPt+U16JxgOMYgCzNFydahXzSZsgjiwu6PkdO7k=; b=OZVvwmvIK/GzThtwfs+Nmf+1oZXIcmrt9l97S3XLTvLG9tKiFZzIH2GET3Gt0CPsOj StEYlQwCs+u4Y37qDSAjeyc/g7Ghop8gez31NNPfIvq9/xWfjH38BTh8HAkA4MMQOWrm 47tmI3edNuKfzyPqDtk2ZTEsWV19ve7EHRGNwMTl2eiUGH4ZqXDleTfAtNjNHnc6Fctb t+jQo7nHqznnZsLEZJMu+MVknh4w3oyFa8qbf5YehoFylAe9d1Jg/GdJmBW2FHm8CAe4 zL5LVyk1uQKuW/4J+dhu7O+2WOOGOkrys503bGKl1VLkb5U+3QxR7G8WAOb9PhkVp9Zg +RIg== X-Gm-Message-State: AOJu0YzD0+VXqsN/XDqr88KXgJQsW/WGmIYkdmG9q6ezXvoP4AWBkKEW nuVvj3OoDT+Aj1h/MX0KVv79RU5UkQo7p0AbnJDhAoXYL3lO0AQoOixDGR7QSBF2j89vBKWSpLK MAZBrNTMuBfo9OWnD1vX4OxV0HKlfbXP7rKFCvTgNTIEUvyEhklHH0w8B8HE= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a4a:d507:0:b0:683:121c:5aa with SMTP id 006d021491bc7-694636dce91mr710508eaf.10.1776420759841; Fri, 17 Apr 2026 03:12:39 -0700 (PDT) Date: Fri, 17 Apr 2026 03:12:39 -0700 In-Reply-To: <001a11c1461c14bf9e0568fd0cd6@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69e20797.050a0220.1de265.0012.GAE@google.com> Subject: Forwarded: [PATCH] hfs: return error when bnode already hashed in From: syzbot To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com. *** Subject: [PATCH] hfs: return error when bnode already hashed in Author: tristmd@gmail.com From: Tristan Madani #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master hfs_bnode_create hfs_bnode_create() checks if the requested node number is already present in the B-tree hash table. If it is, the function emits a WARN_ON(1) and returns the existing node: if (node) { pr_crit("new node %u already hashed?\n", num); WARN_ON(1); return node; } On crafted HFS images with inconsistent B-tree bitmap data, the allocator can repeatedly request creation of node 0 which is already hashed, triggering this WARNING reliably on every mkdir. Replace the WARN_ON with an error return. The node being already hashed when creation is requested indicates filesystem corruption -- returning ERR_PTR(-EIO) allows the caller to handle this gracefully rather than generating a kernel stack trace. Reported-by: syzbot+a19ca73b21fe8bc69101@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=a19ca73b21fe8bc69101 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Tristan Madani --- fs/hfs/bnode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/hfs/bnode.c b/fs/hfs/bnode.c index XXXXXXX..XXXXXXX 100644 --- a/fs/hfs/bnode.c +++ b/fs/hfs/bnode.c @@ -517,8 +517,8 @@ struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num) spin_unlock(&tree->hash_lock); if (node) { pr_crit("new node %u already hashed?\n", num); - WARN_ON(1); - return node; + return ERR_PTR(-EIO); } node = __hfs_bnode_create(tree, num); if (!node) -- 2.43.0