From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ACA081FB2; Fri, 12 Apr 2024 02:32:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712889179; cv=none; b=QXZvJjlC83CxLBmAFD4QWxbLj9Y1Zb2sRkbllIEptN9jkMO8jzneGcz//P7KBuDUP8KIxebW8E7yw02JFcScYbp1PnQNVfD5NnGMUm/AvMDtn4t9zUbRSLSQ2FUBVGTyhIS5KYr0cWhFcYsqlD0RLDuY1vdDHTK0cQCkhNyhLzg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712889179; c=relaxed/simple; bh=A/sZDwPAha0gA/b8dbHLzPkdENaxz954GdpTnaChuH4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=c891j+KJYJQs3gpaALwBwgpgllMuxzEq+cuQuJ1dI1HjBEBHxnNtYKmoY/4pBaRqkR+glRhOHioBxhGKP/IcdzmFO6kG/tDWqhlmVwlKI33yUukwhvtDo4K6Q+XFFSpEhlBT/wEwM7UsQouzHkj7diubgclxBVXGx2qTgZm3/04= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Y1y6jJbH; arc=none smtp.client-ip=192.198.163.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Y1y6jJbH" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1712889178; x=1744425178; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=A/sZDwPAha0gA/b8dbHLzPkdENaxz954GdpTnaChuH4=; b=Y1y6jJbHem8cvcUziQJPcvIK/oSvwQJJQMbHWxDoLng3LDcrYqE2s1K9 E/GHcx2BnZkDFImosvEAk/mUxjWGOsQqFIDvPerO2NWCcwJ15vau7MCPp ZvrdxqvfaiDrNJoIqnNVHxziMj6tCTf5IxQqzHEsY9J54wLi8h6E8seDp AMPnmtmQo5uF5LvdS+NidvjmVK3zi2Jh0ItAT2vtQuLy6S7SYoypln8Pi OTiltqkpGbRcrepUq8g78Hc1Wx7K7cxBGIOHU06g/kPof8CJRPBOch9z9 3/V77VKTQFblW94HJiEJzG7qzCTSaOHyivzXRfjzOfc/CiF/YCZ7DdSke g==; X-CSE-ConnectionGUID: 5yg44BzARVm+jY6AgPMudw== X-CSE-MsgGUID: kKtdSaD3TQ+WsGXqsPRUtg== X-IronPort-AV: E=McAfee;i="6600,9927,11041"; a="8890568" X-IronPort-AV: E=Sophos;i="6.07,194,1708416000"; d="scan'208";a="8890568" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Apr 2024 19:32:57 -0700 X-CSE-ConnectionGUID: KwdjDq55T1msDG2s3IaoFA== X-CSE-MsgGUID: O7WPwnZ+TnypsvhasJK0Qg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,194,1708416000"; d="scan'208";a="25880955" Received: from qzhang4-desk.sh.intel.com (HELO localhost) ([10.239.147.49]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Apr 2024 19:32:55 -0700 Date: Fri, 12 Apr 2024 10:32:53 +0800 From: Qiang Zhang To: Masami Hiramatsu , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Qiang Zhang Subject: Re: [PATCH] bootconfig: use memblock_free_late to free xbc memory to buddy Message-ID: References: <20240412020325.290330-1-qiang4.zhang@linux.intel.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240412020325.290330-1-qiang4.zhang@linux.intel.com> On Fri, Apr 12, 2024 at 10:03:26AM +0800, qiang4.zhang@linux.intel.com wrote: >From: Qiang Zhang > >On the time to free xbc memory, memblock has handed over memory to buddy >allocator. So it doesn't make sense to free memory back to memblock. >memblock_free() called by xbc_exit() even causes UAF bugs on architectures >with CONFIG_ARCH_KEEP_MEMBLOCK disabled like x86. Following KASAN logs >shows this case. > >[ 9.410890] ================================================================== >[ 9.418962] BUG: KASAN: use-after-free in memblock_isolate_range+0x12d/0x260 >[ 9.426850] Read of size 8 at addr ffff88845dd30000 by task swapper/0/1 > >[ 9.435901] CPU: 9 PID: 1 Comm: swapper/0 Tainted: G U 6.9.0-rc3-00208-g586b5dfb51b9 #5 >[ 9.446403] Hardware name: Intel Corporation RPLP LP5 (CPU:RaptorLake)/RPLP LP5 (ID:13), BIOS IRPPN02.01.01.00.00.19.015.D-00000000 Dec 28 2023 >[ 9.460789] Call Trace: >[ 9.463518] >[ 9.465859] dump_stack_lvl+0x53/0x70 >[ 9.469949] print_report+0xce/0x610 >[ 9.473944] ? __virt_addr_valid+0xf5/0x1b0 >[ 9.478619] ? memblock_isolate_range+0x12d/0x260 >[ 9.483877] kasan_report+0xc6/0x100 >[ 9.487870] ? memblock_isolate_range+0x12d/0x260 >[ 9.493125] memblock_isolate_range+0x12d/0x260 >[ 9.498187] memblock_phys_free+0xb4/0x160 >[ 9.502762] ? __pfx_memblock_phys_free+0x10/0x10 >[ 9.508021] ? mutex_unlock+0x7e/0xd0 >[ 9.512111] ? __pfx_mutex_unlock+0x10/0x10 >[ 9.516786] ? kernel_init_freeable+0x2d4/0x430 >[ 9.521850] ? __pfx_kernel_init+0x10/0x10 >[ 9.526426] xbc_exit+0x17/0x70 >[ 9.529935] kernel_init+0x38/0x1e0 >[ 9.533829] ? _raw_spin_unlock_irq+0xd/0x30 >[ 9.538601] ret_from_fork+0x2c/0x50 >[ 9.542596] ? __pfx_kernel_init+0x10/0x10 >[ 9.547170] ret_from_fork_asm+0x1a/0x30 >[ 9.551552] > >[ 9.555649] The buggy address belongs to the physical page: >[ 9.561875] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x45dd30 >[ 9.570821] flags: 0x200000000000000(node=0|zone=2) >[ 9.576271] page_type: 0xffffffff() >[ 9.580167] raw: 0200000000000000 ffffea0011774c48 ffffea0012ba1848 0000000000000000 >[ 9.588823] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 >[ 9.597476] page dumped because: kasan: bad access detected > >[ 9.605362] Memory state around the buggy address: >[ 9.610714] ffff88845dd2ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >[ 9.618786] ffff88845dd2ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >[ 9.626857] >ffff88845dd30000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >[ 9.634930] ^ >[ 9.638534] ffff88845dd30080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >[ 9.646605] ffff88845dd30100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >[ 9.654675] ================================================================== Sorry. Forget to Cc stable. Will send a new one. > >Signed-off-by: Qiang Zhang >--- > lib/bootconfig.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > >diff --git a/lib/bootconfig.c b/lib/bootconfig.c >index c59d26068a64..4524ee944df0 100644 >--- a/lib/bootconfig.c >+++ b/lib/bootconfig.c >@@ -63,7 +63,7 @@ static inline void * __init xbc_alloc_mem(size_t size) > > static inline void __init xbc_free_mem(void *addr, size_t size) > { >- memblock_free(addr, size); >+ memblock_free_late(__pa(addr), size); > } > > #else /* !__KERNEL__ */ >-- >2.39.2 >