From nobody Sun Feb 8 15:58:50 2026 Received: from mail-oo1-f71.google.com (mail-oo1-f71.google.com [209.85.161.71]) (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 9A62D410D05 for ; Thu, 22 Jan 2026 08:42:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.71 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769071353; cv=none; b=jcNFo2rACBsDWJEfJcCPhh0tGxx86y7viESawidHhGIpqxOFfD+iupuFy3M+R+eDIygPOEbvoyIChr/KPXDbwkY5WRYTDvhl7qALo/5sXVY5NNQTjnR5wOruAqleN6uQQrYy2GVfUY5n2QfYU+Fx+QfdkRLHLMji50vv5Gq16hk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769071353; c=relaxed/simple; bh=rJmpGCShSEw5nqdZF3cnjWus3JXYvjleo4fDiEEVgnc=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=gj8Q69bdc0L+dEq0k1Gy5n2y20sFLh2jgseqqPd6MhBuUf9Yzl9QE+Zc6SCuU/rA4G4pn8uxKhZipx9HIj8g+/h+oX4c60B0e8/QazWF9pPzUm4u7uNZx6SOCEcqGpdDGQyei2BlRZFwZQlu631Pzlt7khj9ChsyLoR3+prP754= 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=209.85.161.71 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-oo1-f71.google.com with SMTP id 006d021491bc7-662c684f8f3so175017eaf.3 for ; Thu, 22 Jan 2026 00:42:31 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769071350; x=1769676150; 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=OkDCMqy97XeHHwIk5ZgYM/WiVNKWQXTyahNpeqnpJ6w17r3f9n5sbjpc/jLhSz9XGo 37RKZ8iVabEzOclYawNZPz9JuHMeF0mS8C9fzdhbldWaqXjc6/K1SDsyqnWOMeidGbfk Hw/oxHBZ2cJlrNGTFnLIFkO/cf37OFSZpO1XLU458gy5/Xa/0cwYbLUZhiS3EiF9nwd2 vEkYxKit1t9x4Pcqeqk6HHFqYyi6oZEvrNorJx3F6oNcNoUiZxEf8oC6MnDG4tOeimeH KEEHjY7QWqefCf2NtEBXSLOfaeKOnsrRYCnt7zoQ2Ku6oMdIaYUb2f/tRyVfdN4O/wag zbXA== X-Gm-Message-State: AOJu0YzezSZSJUdyVRt+da0KjCZJ8IO3lYncuDfkt2SeOLseuXcvSr4X q90fzIYolZDuTsr7TG5vsgjO0sbZ9S897/4MCminU9ldZSi0RkkzOG9PFTS9cqkmDciJWqo0dEx G/PHgIv35SPMbcMPIJgo2eM0u4mOYQ9Lb7hUvReoJ1XHYkJ1Uvohr8HToQ0Y= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:1896:b0:65d:2f7:6eab with SMTP id 006d021491bc7-661189002b5mr7878481eaf.32.1769071350563; Thu, 22 Jan 2026 00:42:30 -0800 (PST) Date: Thu, 22 Jan 2026 00:42:30 -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: <6971e2f6.a70a0220.111c58.002a.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