From nobody Sat Feb 7 15:10:55 2026 Received: from mail-oa1-f72.google.com (mail-oa1-f72.google.com [209.85.160.72]) (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 7B5FF3D9052 for ; Thu, 22 Jan 2026 23:34:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.72 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769124863; cv=none; b=oPhyPX1Fd/Carytu9YN5wPdLzrGsRV4B1Y/3afC9WIp1RvJwKob9PB7jUm0d1vens13kbdHufntCe6iZUYELI67t69rqlnIYhnYR/9BRhCRaGe5WQp1KzJ5IcbC3GGdsulAMljdP2ekcaH7Ri+Q9fpfvAmKIPV+DnFHqCuIK0i0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769124863; c=relaxed/simple; bh=rJmpGCShSEw5nqdZF3cnjWus3JXYvjleo4fDiEEVgnc=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=Z0EV+KZQGY7e9lS5ke8jx4rpW6AymQFKRkNnRRz5j53aN6tsqILw8jEB7yJFOfdxs7xy540EeLh563K1a7R3TDYz77HPKrGXuAji5Sr/ZUEuKV0LVDpdhOuy4VlVMawOiSgH9yXwM4LpGzxKMDp3IkSfwIo2llFToEOkF8rXf1c= 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=209.85.160.72 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-oa1-f72.google.com with SMTP id 586e51a60fabf-40805ab764fso4604469fac.1 for ; Thu, 22 Jan 2026 15:34:16 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769124855; x=1769729655; 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=Ll6yMm4YB+jVSU0eIinVBSyDOJJwuthG/XyfSavnIW8=; b=cRhtHEzNB618bgU2CPQUR1obQUDT+OJRJs0F2+O6Z1M8GW4ED6FWXbhEBKYkzbp3pB c22nxB35gDmxMC4dgK1Wh75SQo3evNqMFB8UJQO1nv2bl/wGB2dfku3EAk65q0ygX8no XnEp7IsUkaX4SkPhTX/U90eVYMPGVJ0RC8hBzr+RD+ao+QnAu347e7SyAXT5QsxtZ9hD 0s8EqA+ICQd381v+ewDDCX94KLDEXCRD62BF/2x9OmAikBnwOzXh71f6fDOnobcrSkxQ oVONUCsJPajMRzFGW0ClKcO75F+xYL/o0tOR0mf8EuuNdXYomvlnrG0RLlH8h2e/MEXv uYSQ== X-Gm-Message-State: AOJu0YwZBCRahVKR7RW0jvsKr9ZWQzmRiSHAjvEmUqjxV8EAH7Hyz6a5 KDOjyUl1groUJgTYnzLYBko/R2S4Vlh2p8sGunOH7XLpB2Ecat3R99J+DrzZVzVfOThL/Cn3CD0 lG/cItBUMI+5WNl9vTNZ7+SY368Kx+gZ2/bJl0cPeEMZPiyI6MdjkG6D0XNs= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:458d:b0:65c:fe8b:53b3 with SMTP id 006d021491bc7-662caadf031mr557396eaf.9.1769124854973; Thu, 22 Jan 2026 15:34:14 -0800 (PST) Date: Thu, 22 Jan 2026 15:34:14 -0800 In-Reply-To: <696ea368.a70a0220.34546f.04b7.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6972b3f6.a70a0220.35de72.0001.GAE@google.com> Subject: Forwarded: [PATCH] hfsplus: add debug printk to show partial reads in hfs_brec_read From: syzbot To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Transfer-Encoding: quoted-printable 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] hfsplus: add debug printk to show partial reads in hfs_bre= c_read Author: kartikey406@gmail.com #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git= master Debug patch to demonstrate how hfs_brec_read() can read less data than requested when filesystem is corrupted, leaving uninitialized data in the destination buffer. NOT-FOR-MERGE: debug only Link: https://syzkaller.appspot.com/bug?extid=3Dd80abb5b890d39261e72 Signed-off-by: Deepanshu Kartikey --- fs/hfsplus/bfind.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/hfsplus/bfind.c b/fs/hfsplus/bfind.c index 336d654861c5..9b89dce00ee9 100644 --- a/fs/hfsplus/bfind.c +++ b/fs/hfsplus/bfind.c @@ -217,9 +217,19 @@ int hfs_brec_read(struct hfs_find_data *fd, void *rec,= u32 rec_len) res =3D hfs_brec_find(fd, hfs_find_rec_by_key); if (res) return res; - if (fd->entrylength > rec_len) + printk(KERN_ALERT "HFSPLUS_BREC_READ: rec_len=3D%u, fd->entrylength=3D%u\= n",rec_len, fd->entrylength); + if (fd->entrylength > rec_len) { + printk(KERN_ALERT "HFSPLUS_BREC_READ: ERROR - entrylength > rec_len\n"); return -EINVAL; + } + + if (fd->entrylength < rec_len) { + printk(KERN_ALERT "HFSPLUS_BREC_READ: WARNING - entrylength (%u) < rec_l= en (%u) - PARTIAL READ!\n",fd->entrylength, rec_len); + } + hfs_bnode_read(fd->bnode, rec, fd->entryoffset, fd->entrylength); + + printk(KERN_ALERT "HFSPLUS_BREC_READ: Successfully read %u bytes (expecte= d %u)\n",fd->entrylength, rec_len); return 0; } =20 --=20 2.43.0