From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 825B622EE0; Fri, 12 Apr 2024 21:07:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712956023; cv=none; b=nwSx6XLxSsJfvDDPVNebrR8cSrYptJo6WhCzMQpaRRNuaC4MmdeX7gHmevlk6Xq2ckajS0sbnFZcze17twaQ/PSli2Dd4xUSo/yUq9jRSmKM/UPyPHm4PbPfH+R12XsjqGI+Y/8ALScuzZ+4vm+lmLocH5SVPy6Ba+KnY+Zv3ZU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712956023; c=relaxed/simple; bh=TrVRtQL5XvcfsmBWDYPf9U6S3WrO82Xflk08cB4VDXs=; h=Date:To:From:Subject:Message-Id; b=QpT1zBo5jIkZ2Z6vVTVYg6N/22wr9zbEOwxINN9qHS8CcJw6uJFLbt7lEed8yzhZ1iak38BesHfpRs9LX0y3wjWeQfiBJbODH2fHa9knYpOySgIikgJh13jsOzR17b5PLoplpNZmk3ZHQjcTCZDzmRnws4nV01uEYLOteFI7bQw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=cjCtmVxl; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="cjCtmVxl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D676EC113CC; Fri, 12 Apr 2024 21:07:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1712956022; bh=TrVRtQL5XvcfsmBWDYPf9U6S3WrO82Xflk08cB4VDXs=; h=Date:To:From:Subject:From; b=cjCtmVxl2ZnJ7Iq+OjqA0BnYrKLzeO1kHi/L2SgGrJNPgjP4C87Hk68Jwi2eImI6U eiltDsKMnLkkI89hPqtjsloEsTrBjaRTn5p7YQI/myvXkipgoKoecfHLu/+NqGqlz9 LCvO8tXOKJNSkDlEq27klEyq2wkFZTTe3+dGAKc4= Date: Fri, 12 Apr 2024 14:07:02 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,rppt@linux.ibm.com,mhiramat@kernel.org,qiang4.zhang@intel.com,akpm@linux-foundation.org From: Andrew Morton Subject: + bootconfig-use-memblock_free_late-to-free-xbc-memory-to-buddy.patch added to mm-hotfixes-unstable branch Message-Id: <20240412210702.D676EC113CC@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: bootconfig: use memblock_free_late to free xbc memory to buddy has been added to the -mm mm-hotfixes-unstable branch. Its filename is bootconfig-use-memblock_free_late-to-free-xbc-memory-to-buddy.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/bootconfig-use-memblock_free_late-to-free-xbc-memory-to-buddy.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Qiang Zhang Subject: bootconfig: use memblock_free_late to free xbc memory to buddy Date: Fri, 12 Apr 2024 10:41:04 +0800 At 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] ================================================================== Link: https://lkml.kernel.org/r/20240412024103.3078378-1-qiang4.zhang@linux.intel.com Signed-off-by: Qiang Zhang Cc: Masami Hiramatsu Cc: Mike Rapoport Cc: Signed-off-by: Andrew Morton --- lib/bootconfig.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/bootconfig.c~bootconfig-use-memblock_free_late-to-free-xbc-memory-to-buddy +++ a/lib/bootconfig.c @@ -63,7 +63,7 @@ static inline void * __init xbc_alloc_me static inline void __init xbc_free_mem(void *addr, size_t size) { - memblock_free(addr, size); + memblock_free_late(__pa(addr), size); } #else /* !__KERNEL__ */ _ Patches currently in -mm which might be from qiang4.zhang@intel.com are bootconfig-use-memblock_free_late-to-free-xbc-memory-to-buddy.patch