From nobody Sat Feb 7 21:11:08 2026 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 BE1C7239085 for ; Wed, 21 Jan 2026 05:24:58 +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=1768973100; cv=none; b=VTl7QleCW6btWoHD1WoyTgPgg9vJbLAG/ueWKkL7Y02Zt5O3hDL9TUjkFtBFo0bdHSeMqvV6aqFd3j0Q6MfHAHX0ebkGYaSB3afXZmeYKxH1RbHClTbAaTF/f8VXVIEiCpFgKKlcbX1Nav3jASAKt9c6cLLMm+05VlB+1CLkJhM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768973100; c=relaxed/simple; bh=4jlqdxbHCOSodc+vZxreH2Aah3l1XBIlkapuHnwfvXQ=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=a9QaqX0Pbtw9KplyOrHE76ROrr8JgIo0GQHlmVBMup7NTLY0bknoA05+pBABC8H0r4cyyyxNNGUzs1PZLn/ONmHthBhuiUwnfHC2U2rfrvEg2Fs7icOhYloHyB6SpnjK0sYZsJdWpbprXRgweF7bYPPhWbkEPh/2Cp/91NCIr8A= 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 46e09a7af769-7cfd1080f66so11815640a34.2 for ; Tue, 20 Jan 2026 21:24:58 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768973097; x=1769577897; 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=pCw3Pj4hrp/GJU6mlzZsHnLr87XoNEXua/A4W8WA9mo=; b=ojG+r6WTVC8oujEd5kxIAyVP/1L4bFbUZQ8qOAS6ppCmLyGzFzkNI0uYrhZOAoGjOr 9hdm09zv7ncPRY/omfK1cZSjIxTl+oWORxSKbrusRoLY8eM+G82gws0RjNYonL5W2oiM T0BfLTAS1BMOXC8Y34OjpQrqULoHS3pQBxUoBjJBAgZkYqIoXW+SJrn7VB+W8ssSqpuK aLNFLZarLAsvaW8zk3pwr/je1/LO2rxyLwbu/K8E1s+w9q9x39xZtKGruGzlTZpyEpbx uinuO1GRy8dKckM9ufIpfJ4EWPJEsODr0XxqeD4bN7DOO/V2D37VzCFHPDTjwh269IsN IQZw== X-Gm-Message-State: AOJu0YxwgEeYyPdWon2UB/mwFzEh0LaAy9ts/5emd0pE2Udn1NoxI15X C0q9l97tL9taqPQWkYHAxCYSOhtQJgwacsjwofhhFUesJDyQTJQxsc158/OUjLxbPCmINGiQCxc eDNs2lDi41QmkiXWKUUf0ehupD4QVGMEzQYNxR+z5iySGJK1IdfhXHibteuE= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:2911:b0:65d:3c7:b62 with SMTP id 006d021491bc7-662affdd5d9mr1740201eaf.35.1768973097721; Tue, 20 Jan 2026 21:24:57 -0800 (PST) Date: Tue, 20 Jan 2026 21:24:57 -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: <69706329.050a0220.706b.0009.GAE@google.com> Subject: Forwarded: [PATCH] hfsplus: add debug printk to show uninitialized values in case_fold 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 uninitialized values in = case_fold Author: kartikey406@gmail.com #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git= master This is a debug patch to demonstrate the uninit-value bug reported by syzbot. Added printk in case_fold() to show what uninitialized values are being read from the unicode array and used as array indices. This patch intentionally does NOT include the fix (no initialization of tmp variable) to demonstrate the bug behavior. Link: https://syzkaller.appspot.com/bug?extid=3Dd80abb5b890d39261e72 Signed-off-by: Deepanshu Kartikey --- fs/hfsplus/unicode.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/fs/hfsplus/unicode.c b/fs/hfsplus/unicode.c index d3a142f4518b..418806c27943 100644 --- a/fs/hfsplus/unicode.c +++ b/fs/hfsplus/unicode.c @@ -11,7 +11,6 @@ =20 #include #include - #include =20 #include "hfsplus_fs.h" @@ -22,12 +21,18 @@ static inline u16 case_fold(u16 c) { u16 tmp; - + pr_alert("CASE_FOLD: Input c=3D0x%04x, c>>8=3D0x%02x (this is array index= !)\n", c, c >> 8); tmp =3D hfsplus_case_fold_table[c >> 8]; - if (tmp) + pr_alert("CASE_FOLD: table[0x%02x]=3D0x%04x\n", c >> 8, tmp); + + if (tmp) { + pr_alert("CASE_FOLD: Second lookup: table[0x%04x + 0x%02x]\n",tmp, c & 0= xff); tmp =3D hfsplus_case_fold_table[tmp + (c & 0xff)]; - else + } else { tmp =3D c; + } + pr_alert("CASE_FOLD: Final result=3D0x%04x\n", tmp); + return tmp; } =20 --=20 2.43.0