From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f43.google.com (mail-oa1-f43.google.com [209.85.160.43]) (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 A6759DDB8 for ; Sat, 1 Jun 2024 02:57:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.43 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717210640; cv=none; b=RPi13Di3FuoRzHvtda7ZqIo+2SIoLCEqPo4uFOfgnZKojZv1/F4+MfOKdYhdHh9Dcm8t5EX887E5iNMKWPqaA1O0h32aF4HvulGc/olgXv22ingJi7jvTvOGZLWBjPYK6gGdbXeFZRz5qy2XshrSMX0lvKw8kSgA/YoePJnUsFM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717210640; c=relaxed/simple; bh=W66ss44jfXYw49cQTw3aqHq6yM0zLeS4PO8jf+eIcX0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Qhvg6aO4muPTuMuhbk9/OwMVw+/t6TsJbRrYgv0AGBWKg4Gk6Kp/cco3dJVew+/AuE5a64TyYC0Vqq3dQVLYF0tDCh/cbyNJ5/LFXDsedHKX/BNffziRMGk2kSyzyfm2u/crf0gtvVkklgHjTAnPY32OrwZ0KPleXbthz12DDAU= 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=TyFyonTs; arc=none smtp.client-ip=209.85.160.43 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="TyFyonTs" Received: by mail-oa1-f43.google.com with SMTP id 586e51a60fabf-24ca21014ccso1364270fac.1 for ; Fri, 31 May 2024 19:57:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1717210637; x=1717815437; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=6g0RzMq72+EjgwD7VB3pJoWW1gkEWDC8hXVu7dCphXQ=; b=TyFyonTsHnAs26YeThZrPR2OvUqL61psKfZKPzyaDJBYWfSaIyD8loiD+0pg2gx7Ib Rzf1zvM/GWKys29CquLBgbpzzMoEHZNNeIrgUQ6icbksN3gYAKDROVukjhRKo+b/M17s nMmmi+Y4lPfzNbmfDLukdo+hOV8/hOPPEtvDK3Asb3OLNdXl7pp36+6jDI1SoRr60sGC iNwiefvEKIVDBjtvwjXkTZ3vh86lunMBWbu8fyYeNWzwhCtSEcBkpZXsvrwy5RcNAvxZ ROD+7TPT85mSXIsdpiRwaREXqEiTidRooVMITp1irIKQj+0BO2MjD9Svleh9XGlv7SqT Rt4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1717210637; x=1717815437; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=6g0RzMq72+EjgwD7VB3pJoWW1gkEWDC8hXVu7dCphXQ=; b=RQ+zKRE8U+lr8swJVzjf0W4ccwHm2BKl87TCj+FBKocGCicdNBU2lbwX5yK/Ydtjdi a4yLnPrU7Gib9mptKQwSDWfHhQqM2HDnamgRI5HrjYCJFNzMVgmNC620vz4xF40Nr2mQ 72rtrSeM205RiDK83fMWWjla/M00EYg3M6zQgeyjesYDx96Uz0fhsh8GEojKqU2lzGQ8 WbTBLm/pQD8SGnAY652KX5lM7k6NLDZnJn42A1zpIRTFSePsHNCEOZ1gPflnCc+5NPyU hXvU/YWlfAIbI7aha8KLtd0U/8l+fhw7oQT0rqwOWC4JxT8YD53JzuYQ/C79oqbgWISt lOBQ== X-Forwarded-Encrypted: i=1; AJvYcCXG0XpF0LaDoV3dNf+JA7lmAHRFCDbh/zTryYeISgqYac1dXSXxBcpF/6Dnf7lakuhojg1l8QI5U8yX3nA46M630/vPLaUfLCxL6c8Q X-Gm-Message-State: AOJu0Yzq+fH2WumUOyHqmEoBxh80LuV2yquwf3+VPNT5Y04wrSGLx8NI AUowu/Sw6x8RCbxLap04z5bpM6IXRjrhoJyZzwptB+4ydEoUlBen X-Google-Smtp-Source: AGHT+IGAZS0BCANLIKut5FzDyIGtcZaKcQ5YilJ7KyLkjBQmdPnJI/dVBGizPg/F+4WeIJEri8LItw== X-Received: by 2002:a05:6870:82a9:b0:24f:eebc:64f1 with SMTP id 586e51a60fabf-2508c118a9bmr4053088fac.40.1717210637444; Fri, 31 May 2024 19:57:17 -0700 (PDT) Received: from localhost.localdomain ([121.185.186.233]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-70242b300ddsm2047503b3a.191.2024.05.31.19.57.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 31 May 2024 19:57:17 -0700 (PDT) From: Jeongjun Park To: darklight2357@gmail.com Cc: aha310510@gmail.com, linux-kernel@vger.kernel.org, syzbot+13e8cd4926977f8337b6@syzkaller.appspotmail.com, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [jfs?] UBSAN: shift-out-of-bounds in extAlloc (2) Date: Sat, 1 Jun 2024 11:56:07 +0900 Message-Id: <20240601025607.22180-1-aha310510@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi, Thanks to the points you pointed out, I was able to confirm that there was a rudimentary mistake in my patch. And as you suggested, I think it would be a good idea to handle the two situations separately. However, if you only check when there is a value of sizeof(s64) * 8 or more in bmp->db_maxfreebud, the value will change to a negative number when bmp->db_maxfreebud is 63 because max is an s64 data type. Therefore, I think it is right to slightly modify the conditions. Regards. --- fs/jfs/jfs_extent.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/jfs/jfs_extent.c b/fs/jfs/jfs_extent.c index 63d21822d309..3d1273d35b13 100644 --- a/fs/jfs/jfs_extent.c +++ b/fs/jfs/jfs_extent.c @@ -316,6 +316,9 @@ extBalloc(struct inode *ip, s64 hint, s64 * nblocks, s64 * blkno) if (bmp->db_maxfreebud == -1) return -ENOSPC; + if (bmp->db_maxfreebud >= sizeof(s64) * 8 - 1) + return -EINVAL; + max = (s64) 1 << bmp->db_maxfreebud; if (*nblocks >= max && *nblocks > nbperpage) nb = nblks = (max > nbperpage) ? max : nbperpage; -- 2.34.1