From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.10]) (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 EE73A367F31; Mon, 27 Apr 2026 05:40:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777268462; cv=none; b=vC+ILb/368+XfPtRTRpz1JV3Pdg6vkqgYdEg1Cb0TStk2B4wKNK/ULWzReOfX94VC9OSJN2r40ldX9aylYV06f16UFD8l/8P2Tp4od3oMaBB/TEtxML6ldpq+MHEKvYlkP+aWk+a6ke+BtbxnOJQ7suoc0NQiRni1QbiNb6aKiI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777268462; c=relaxed/simple; bh=dUPf/X9No1sq9njMsSwhAAxQEorToDmrXCtKtn3sOBY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AqQhSISmm4AeJIS5p3HenEtwOkMV41KsVblRm8L78x30Yb6Di1dsT2AHon9UUrg+EH7BRgsuj+IZG6CjoZfe5z1kCOSfobqd8298vQliZC5eatgfBOeGnTFtrSZ3rQrXsY6jsiwMAtlb91wrj8iTiEQjELLAnPW5B80RSvSJ5Ew= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=VpHG8tlt; arc=none smtp.client-ip=192.198.163.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass 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="VpHG8tlt" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1777268460; x=1808804460; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=dUPf/X9No1sq9njMsSwhAAxQEorToDmrXCtKtn3sOBY=; b=VpHG8tltuzsBPmr4MtVtobSaOr2D6iHPziAFUcmvT+rNY7dznh+A4vBo hyRXu0JtCL4S/mEJrOGTQAzUGsw5b1rLkRK3DScGEMahjRoYycO0YNkjY 2tkzUqFycICdCB5+MoFE3U/pEdFt6YbwHPmC0eSdVBbZRUR1Iikk+oH57 7SKxGCrJL+SoZsXuKC4Bjw+ouzchCTnRObwgLPVPKdkGePyflbqDhChUl 7pO56xn+FhriOIs9QVV26oBpMCmRXknb2E1WrqZpVkPyiW08VBeu3TPgh tNrnxXaUggOnA5SuFsFqFDISWomfgIkiNMBCfKWGVFhWr4MkiF52Xw+Uq g==; X-CSE-ConnectionGUID: 36O9zWppRXKDN7uuzvu2GA== X-CSE-MsgGUID: v2GqHLLHSmOZHN0O3hDCQQ== X-IronPort-AV: E=McAfee;i="6800,10657,11768"; a="89528069" X-IronPort-AV: E=Sophos;i="6.23,201,1770624000"; d="scan'208";a="89528069" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by fmvoesa104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Apr 2026 22:40:59 -0700 X-CSE-ConnectionGUID: 3n3IXWR+Q1KZMfnb1TTmDQ== X-CSE-MsgGUID: buhYigEkQ9GVVzmojM+6xg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,201,1770624000"; d="scan'208";a="235313399" Received: from black.igk.intel.com ([10.91.253.5]) by fmviesa004.fm.intel.com with ESMTP; 26 Apr 2026 22:40:57 -0700 Received: by black.igk.intel.com (Postfix, from userid 1001) id 65C4F95; Mon, 27 Apr 2026 07:40:56 +0200 (CEST) Date: Mon, 27 Apr 2026 07:40:56 +0200 From: Mika Westerberg To: Michael Bommarito Cc: linux-usb@vger.kernel.org, Mika Westerberg , Andreas Noever , Yehezkel Bernat , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v2 4/4] thunderbolt: test: add KUnit regression tests for XDomain property parser Message-ID: <20260427054056.GL557136@black.igk.intel.com> References: <20260415032335.2826412-1-michael.bommarito@gmail.com> <20260415045246.GR3552@black.igk.intel.com> <20260415123221.225149-1-michael.bommarito@gmail.com> <20260415123221.225149-5-michael.bommarito@gmail.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260415123221.225149-5-michael.bommarito@gmail.com> On Wed, Apr 15, 2026 at 08:32:20AM -0400, Michael Bommarito wrote: > Add three KUnit cases that exercise the defects fixed by the sibling > commits in this series by feeding crafted XDomain property blocks to > tb_property_parse_dir(): > > tb_test_property_parse_u32_wrap - entry->value = 0xFFFFFF00 and > entry->length = 0x100 so their u32 sum 0x100000000 wraps to 0 > under the block_len guard; without the fix the subsequent > parse_dwdata() reads attacker-directed OOB memory. > > tb_test_property_parse_recursion - two DIRECTORY entries pointing > at each other, driving __tb_property_parse_dir() recursion; > without the fix the kernel stack is exhausted. > > tb_test_property_parse_dir_len_underflow - a DIRECTORY entry with > length < 4 so non-root content_len = dir_len - 4 wraps size_t; > without the fix nentries is huge and the entry walk runs OOB. > > Each test asserts tb_property_parse_dir() returns NULL on the > crafted input. With CONFIG_KASAN=y, running these on the pre-fix > kernel reproduces an oops inside __tb_property_parse_dir (KASAN > shadow-memory fault for the u32_wrap case, stack-guard trip for > recursion, OOB read past block for dir_len underflow). Post-fix > they pass cleanly. > > Run with: > ./tools/testing/kunit/kunit.py run --arch=x86_64 \\ > --kconfig_add CONFIG_PCI=y --kconfig_add CONFIG_NVMEM=y \\ > --kconfig_add CONFIG_USB4=y --kconfig_add CONFIG_USB4_KUNIT_TEST=y \\ > --kconfig_add CONFIG_KASAN=y 'thunderbolt.tb_test_property_parse_*' > > Assisted-by: Claude:claude-opus-4-6 > Assisted-by: Codex:gpt-5-4 > Signed-off-by: Michael Bommarito > --- > drivers/thunderbolt/test.c | 127 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 127 insertions(+) > > diff --git a/drivers/thunderbolt/test.c b/drivers/thunderbolt/test.c > index 1f4318249c22..22f4107fcb8d 100644 > --- a/drivers/thunderbolt/test.c > +++ b/drivers/thunderbolt/test.c > @@ -2852,7 +2852,134 @@ static void tb_test_property_copy(struct kunit *test) > tb_property_free_dir(src); > } > > +/* > + * Reproducers for three memory-safety defects in > + * drivers/thunderbolt/property.c reached from a crafted XDomain > + * PROPERTIES_RESPONSE payload. Without the fix these trip KASAN or > + * smash the kernel stack; with the fix each returns NULL cleanly. > + */ > +static void tb_test_property_parse_u32_wrap(struct kunit *test) > +{ > + u32 *block = kunit_kzalloc(test, 500 * sizeof(u32), GFP_KERNEL); > + struct tb_property_dir *dir; > + struct { > + u32 key_hi, key_lo; > + u16 length; > + u8 reserved; > + u8 type; > + u32 value; > + } *e; This is same as tb_property_entry so probably should use that or better do it like we have in that root_directory as array of u32. At least do not duplicate it all over. > + > + /* Root header: magic + length=6 (single entry body of 4 dwords + > + * 2 slack, keeps walk within block[]). */ The block comment format is /* * .. * .. */ Ditto everywhre. > + block[0] = 0x55584401; > + block[1] = 6; > + > + /* Crafted DATA entry at block[2..5]: value = 0xFFFFFF00 and > + * length = 0x100 are u32/u16 such that the u32 sum 0x100000000 > + * wraps to 0, passing the sum <= block_len guard even though > + * the real offset is block + 0xFFFFFF00 * 4 (~16 GiB past the > + * block). The subsequent parse_dwdata() at property.c:132 > + * copies entry->length*4 = 1024 bytes from that wild address > + * into a fresh kcalloc buffer. > + */ > + e = (void *)&block[2]; > + e->key_hi = 0x61616161; > + e->key_lo = 0x61616161; > + e->length = 0x100; > + e->type = 0x64; /* TB_PROPERTY_TYPE_DATA */ This can use TB_PROPERtY_TYPE_DATA. > + e->value = 0xFFFFFF00; > + > + dir = tb_property_parse_dir(block, 500); > + /* With the fix this returns NULL; without it, KASAN splats in > + * be32_to_cpu_array() / memcpy reading block + value*4 out of > + * bounds. Assert on the safe outcome: a NULL dir. */ > + KUNIT_EXPECT_NULL(test, dir); > + tb_property_free_dir(dir); > +} > + > +static void tb_test_property_parse_recursion(struct kunit *test) > +{ > + u32 *block = kunit_kzalloc(test, 500 * sizeof(u32), GFP_KERNEL); > + struct tb_property_dir *dir; > + struct entry { > + u32 key_hi, key_lo; > + u16 length; > + u8 reserved; > + u8 type; > + u32 value; > + } *e, *child_e; > + > + block[0] = 0x55584401; > + block[1] = 4; /* rootdir length = one entry */ > + > + /* DIRECTORY entry pointing at dir_offset=2 with length=16. > + * When parsed as non-root: content_offset = 6, content_len = 12, > + * nentries = 3. The child's first entry at block[6] is also > + * DIRECTORY pointing at 2, so the recursion oscillates between > + * two dir_offsets until the kernel stack is exhausted. > + */ > + e = (void *)&block[2]; > + e->key_hi = 0x61616161; > + e->key_lo = 0x61616161; > + e->length = 16; > + e->type = 0x44; /* TB_PROPERTY_TYPE_DIRECTORY */ This can use TB_PROPERTY_TYPE_DIRECTORY. > + e->value = 2; > + > + child_e = (void *)&block[6]; > + child_e->key_hi = 0x62626262; > + child_e->key_lo = 0x62626262; > + child_e->length = 16; > + child_e->type = 0x44; > + child_e->value = 2; > + > + dir = tb_property_parse_dir(block, 500); > + /* With the fix this returns NULL at TB_PROPERTY_MAX_DEPTH (8). > + * Without it, the kernel stack-guard fires ~50-80 frames in > + * and the kunit thread oopses. */ > + KUNIT_EXPECT_NULL(test, dir); > + tb_property_free_dir(dir); > +} > + > +static void tb_test_property_parse_dir_len_underflow(struct kunit *test) > +{ > + u32 *block = kunit_kzalloc(test, 500 * sizeof(u32), GFP_KERNEL); > + struct tb_property_dir *dir; > + struct entry { > + u32 key_hi, key_lo; > + u16 length; > + u8 reserved; > + u8 type; > + u32 value; > + } *e; > + > + block[0] = 0x55584401; > + block[1] = 4; > + > + /* DIRECTORY entry with length=3. When parsed as non-root, > + * content_len = dir_len - 4 underflows size_t to ~SIZE_MAX, > + * nentries = SIZE_MAX/4. The for-loop walks entries past the > + * block, reading OOB on each iteration. > + */ > + e = (void *)&block[2]; > + e->key_hi = 0x61616161; > + e->key_lo = 0x61616161; > + e->length = 3; > + e->type = 0x44; Thi can use TB_PROPERTY_TYPE_DIRECTORY. > + e->value = 6; > + > + dir = tb_property_parse_dir(block, 500); > + /* With the fix: NULL. Without: KASAN splat on > + * block[content_offset + i*4] for i > 124 (past the 500-dword > + * block). */ > + KUNIT_EXPECT_NULL(test, dir); > + tb_property_free_dir(dir); > +} > + > static struct kunit_case tb_test_cases[] = { > + KUNIT_CASE(tb_test_property_parse_u32_wrap), > + KUNIT_CASE(tb_test_property_parse_recursion), > + KUNIT_CASE(tb_test_property_parse_dir_len_underflow), > KUNIT_CASE(tb_test_path_basic), > KUNIT_CASE(tb_test_path_not_connected_walk), > KUNIT_CASE(tb_test_path_single_hop_walk), > -- > 2.53.0