From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f53.google.com (mail-pj1-f53.google.com [209.85.216.53]) (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 97A75227B95 for ; Mon, 13 Oct 2025 13:47:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760363249; cv=none; b=owZOn1Z1yToo/KQrUc0FHOTscwjmngTv/gWNx17DiR6GuDniozaicAvffFK25L1uqm+hfTi0rgKLf10MkCup0YsNGD77s6dGdY5uC3xYnm/tFXNwC4tcaA2ZmWNp+V//lzC+PBSO4qjKRTS9co6YZRFDsOI0RvGK384oL97Zuy8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760363249; c=relaxed/simple; bh=Swp4+xHTqvgYr+z64DMuU57MVlL3j0v8jDSlSv8/1Rs=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=amHPzRm1S+EyFIqB2v7+deHGLiC4sBKLXE4BuxYaMTh36+TyWyhjqP0UFzhxFnzGKVtNc6yqK7xtF1diNlWGoupMWAfegDU7iJ4fupQCXj1lsnfOtBOENkz0DpQkGBc0PQxJ3mNCmbkBGv8J4ksQWVbVc5nx9AVZleDXPx9fd4o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=io1hlNIi; arc=none smtp.client-ip=209.85.216.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="io1hlNIi" Received: by mail-pj1-f53.google.com with SMTP id 98e67ed59e1d1-3306eb96da1so3321782a91.1 for ; Mon, 13 Oct 2025 06:47:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1760363247; x=1760968047; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=teOPnCrlstkFyH9+vuIz1dE4A6eVshfJueJ5oAZ3QHs=; b=io1hlNIiVqXlc1wjOO1Rak6dG0PCmd87m6yKf7aSc0mEZV0nxR+OmHBUv4xbgPmchU UT+ohTXQGkOWgu7RQUvjFsuw3jx95XXtFJj20VylppMWy9L9VAsDDkBiNpYVMusvyQ3o 5wjdI0ZxwK366brx/sQD+9O8TEEWQm7k3m7aFlh6Nc3UJ0aqRWHBeoXzgROm4kJ/VXaI 3pp5GEfkHcyzG+rdmiiYdmYN4N9F+SvKTQaUK/x/f4/7Fajd7S3IkP6Zi9AcdDIoz+tV 1+5p1fKcdPVgXYtm6+w3qn6va/Hm+qiv9MFZnQXvkRaD0TGc+zOt81ZvR423VgKgR1Xu jzOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760363247; x=1760968047; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=teOPnCrlstkFyH9+vuIz1dE4A6eVshfJueJ5oAZ3QHs=; b=HQHT+2OJ6Brnn8ZQxYBttmHBvuMFj7u6O3d9g3z8cx89QR1jeVSFTUgMwNBI/MhqST aC9KR29f3BTKeSiUP9MvDcrWxKkbf16Mv1ZD03VOT4RnTKt/do6vkE3FMn0KXcgnNxuH cneDdP0x9ZD5A99zIEcAPHZyhY4RNkNzZC1hNPsqTGISR63HctWqvLGAw0ws0n4wM8Y8 qn8JcgkV4COfOoYqNX9kXDvRISp/4uXlcf05tZ7etQALuRNy6FbwDu+4BIvu6DrfjoU+ j49rALUaTDAyweqkXfNvrJC6sSATUdbcxQkiFSK3axhqDb8c4twxllgKrI8kYhzeI/Io 69Dg== X-Forwarded-Encrypted: i=1; AJvYcCVHzOwM3Vtib61ryzl7No4VVreDhso7rdlZlm2i6zkD1mTx7oWvyxI2HHFk5xWlMWjV6998+cWtpNCaRsEg@vger.kernel.org X-Gm-Message-State: AOJu0YxGcDcRFu615TBStkwogc3hlozDbFUVOc4kmzz9qWjfTmU6jtNV Fs+BudXz0hHs6uqIsqSLdSjhaZZlvrREZ3NJUIBCydl0qtlFbp5+hLY1 X-Gm-Gg: ASbGnctp7rAyfjHzmFhrt09pzSsC08fYdMpiVgivAGGl3PgW5cKT/klIoL2vYIAj9mO b5LilXxMdivEbYdTBz5eF5trNa6Y9mqgQSj+GDY1urYWv3O7MVv4NxrIHIAYO7RB60fMCHHUodR 7qqbkAsBFIeKKLCie5pIxuhIwO6jEGLbGXDmYS3xim+0ExxU0VrdzQ/V13RYgmUeXiOxIs93dko tZxv8lIPQHxQpWu9n2Fi5RF2aPAEtjLXZUeaRjJKCIdKSEK2gCC8a0ezohx8B4tqtN5TmG2nHAZ +7UTyy07hDil3RQaxF35Ufm8lZIrot7omk4ByAiWwhrfBz2YpfCTbbT16iuOd02G7OVcRq1B1HT tYPB2wFwnafLY+aV74X387RuqE6YW4hMvczWpbIwuflAsCEiScjBWQGxgj33Dyx8EQ/qJ X-Google-Smtp-Source: AGHT+IFD9xM53HQ+bQQDPEQgAUdL3IwH91zz8prxo1co6ZEPN18n39S7OZmUBWp8Eqf4/zWeSLysJQ== X-Received: by 2002:a17:90b:1d06:b0:32e:2c90:99a with SMTP id 98e67ed59e1d1-33b513b4b51mr31706554a91.35.1760363246720; Mon, 13 Oct 2025 06:47:26 -0700 (PDT) Received: from name2965-Precision-7820-Tower.. ([121.185.186.233]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-33b626d61aasm12295067a91.17.2025.10.13.06.47.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Oct 2025 06:47:26 -0700 (PDT) From: Jeongjun Park To: Namjae Jeon , Sungjong Seo Cc: Yuezhang Mo , Al Viro , pali@kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, syzbot+98cc76a76de46b3714d4@syzkaller.appspotmail.com, Jeongjun Park Subject: [PATCH v3] exfat: fix out-of-bounds in exfat_nls_to_ucs2() Date: Mon, 13 Oct 2025 22:47:08 +0900 Message-Id: <20251013134708.1270704-1-aha310510@gmail.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Since the len argument value passed to exfat_ioctl_set_volume_label() from exfat_nls_to_utf16() is passed 1 too large, an out-of-bounds read occurs when dereferencing p_cstring in exfat_nls_to_ucs2() later. And because of the NLS_NAME_OVERLEN macro, another error occurs when creating a file with a period at the end using utf8 and other iocharsets, so the NLS_NAME_OVERLEN macro should be removed and the len argument value should be passed as FSLABEL_MAX - 1. Cc: Reported-by: syzbot+98cc76a76de46b3714d4@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=98cc76a76de46b3714d4 Fixes: 370e812b3ec1 ("exfat: add nls operations") Signed-off-by: Jeongjun Park --- fs/exfat/file.c | 2 +- fs/exfat/nls.c | 3 --- 2 files changed, 1 insertion(+), 4 deletions(-) diff --git a/fs/exfat/file.c b/fs/exfat/file.c index f246cf439588..7ce0fb6f2564 100644 --- a/fs/exfat/file.c +++ b/fs/exfat/file.c @@ -521,7 +521,7 @@ static int exfat_ioctl_set_volume_label(struct super_block *sb, memset(&uniname, 0, sizeof(uniname)); if (label[0]) { - ret = exfat_nls_to_utf16(sb, label, FSLABEL_MAX, + ret = exfat_nls_to_utf16(sb, label, FSLABEL_MAX - 1, &uniname, &lossy); if (ret < 0) return ret; diff --git a/fs/exfat/nls.c b/fs/exfat/nls.c index 8243d94ceaf4..57db08a5271c 100644 --- a/fs/exfat/nls.c +++ b/fs/exfat/nls.c @@ -616,9 +616,6 @@ static int exfat_nls_to_ucs2(struct super_block *sb, unilen++; } - if (p_cstring[i] != '\0') - lossy |= NLS_NAME_OVERLEN; - *uniname = '\0'; p_uniname->name_len = unilen; p_uniname->name_hash = exfat_calc_chksum16(upname, unilen << 1, 0, --