From nobody Thu Dec 18 00:09:27 2025 Received: from out-176.mta0.migadu.com (out-176.mta0.migadu.com [91.218.175.176]) (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 84448221477 for ; Thu, 5 Dec 2024 17:05:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.176 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733418355; cv=none; b=mS/+ufK/ynKy+FHlNI20+8s9sdnXOAUikwR5+b17LUSpzd1ygKRSsNdffo/kNEZApSkfhbrNX7JLJxSe3Gmo7LwGO+XQCNczPn8zX+4lfDbNFtqVXWkB83aOAgMBjDc/H5FiwaLSbXtmOUwS0W4YPL1MOaTf/Tw8VEzjapXL9fs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733418355; c=relaxed/simple; bh=A6c4QABXiyL7inv/ysnldOUOjrdga7qDI+X9Cm5iwzU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=MVnbBlyPKDXRjLXhIgOVeUdAiMi8lacMEXE9qmMNRt5ODa/S1HoSr7VhVnooJ9O+sS38YuLlQ6huchpCWL4C//G0oIZivKQu7Bjw7fykljqvVscum+c1dYaokPv7Oa3fwlNrX5wJ9rN3jNuIRcOTm1+HCdqjiPeAglZXqFT35wQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=Qcib04EA; arc=none smtp.client-ip=91.218.175.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="Qcib04EA" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1733418350; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DwsmvYHNmo6qtxFQ5P7SXeQn3VEcbQIjYoq50ZRaOUg=; b=Qcib04EAhlmqGZaoKdQnoAuNK5IFCIpZt2O6VvFV/1O+mI8YunnKtZPk2YVM/BlwU1WMh3 V0mAh5HnZ04HOWyRN8KF4/MvjL6hL1CkwQGDUKZh/I26k5HLSfujjzaDM+18W7zN2h6yqM WnQEEytyqvn5OMcyZn8Kjk17MNKidxQ= From: Hao Ge To: surenb@google.com, kent.overstreet@linux.dev, akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, hao.ge@linux.dev, Hao Ge Subject: [PATCH v3] mm/alloc_tag: fix vm_module_tags_populate's KASAN poisoning logic Date: Fri, 6 Dec 2024 01:05:28 +0800 Message-Id: <20241205170528.81000-1-hao.ge@linux.dev> In-Reply-To: <43bf216e-18f7-680c-ae75-773b03c8dc00@linux.dev> References: <43bf216e-18f7-680c-ae75-773b03c8dc00@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" From: Hao Ge After merge commit 233e89322cbe ("alloc_tag: fix module allocation tags populated area calculation"), We still encountered a KASAN bug. This is because we have only actually performed page allocation and address mapping here. we need to unpoisoned portions of underlying memory. Here is the log for KASAN: [ 5.041171][ T1] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [ 5.042047][ T1] BUG: KASAN: vmalloc-out-of-bounds in move_module+0x2= c0/0x708 [ 5.042723][ T1] Write of size 240 at addr ffff80007e510000 by task s= ystemd/1 [ 5.043412][ T1] [ 5.043523][ T72] input: QEMU QEMU USB Tablet as /devices/pci0000:00/0= 000:00:01.1/0000:02:001 [ 5.043614][ T1] CPU: 0 UID: 0 PID: 1 Comm: systemd Not tainted 6.13.= 0-rc1+ #28 [ 5.045560][ T1] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 = 02/06/2015 [ 5.046328][ T1] Call trace: [ 5.046670][ T1] show_stack+0x20/0x38 (C) [ 5.047127][ T1] dump_stack_lvl+0x80/0xf8 [ 5.047533][ T1] print_address_description.constprop.0+0x58/0x358 [ 5.048092][ T72] hid-generic 0003:0627:0001.0001: input,hidraw0: USB = HID v0.01 Mouse [QEMU 0 [ 5.048126][ T1] print_report+0xb0/0x280 [ 5.049682][ T1] kasan_report+0xb8/0x108 [ 5.050170][ T1] kasan_check_range+0xe8/0x190 [ 5.050685][ T1] memcpy+0x58/0xa0 [ 5.051135][ T1] move_module+0x2c0/0x708 [ 5.051586][ T1] layout_and_allocate.constprop.0+0x308/0x5b8 [ 5.052219][ T1] load_module+0x134/0x16c8 [ 5.052671][ T1] init_module_from_file+0xdc/0x138 [ 5.053193][ T1] idempotent_init_module+0x344/0x600 [ 5.053742][ T1] __arm64_sys_finit_module+0xbc/0x150 [ 5.054289][ T1] invoke_syscall+0xd4/0x258 [ 5.054749][ T1] el0_svc_common.constprop.0+0xb4/0x240 [ 5.055319][ T1] do_el0_svc+0x48/0x68 [ 5.055743][ T1] el0_svc+0x40/0xe0 [ 5.056142][ T1] el0t_64_sync_handler+0x10c/0x138 [ 5.056658][ T1] el0t_64_sync+0x1ac/0x1b0 Fixes: 233e89322cbe ("alloc_tag: fix module allocation tags populated area = calculation") Signed-off-by: Hao Ge Acked-by: Suren Baghdasaryan --- v3: Based on Suren's suggestion, I modified the code,Thank you for Suren. I realized that the 'poisoned' is actually not needed, so I removed it Due to these changes, update the commit message. v2: Add comments to kasan_unpoison_vmalloc like other places. commit 233e89322cbe ("alloc_tag: fix module allocation tags populated area calculation") is currently in the mm-hotfixes-unstable branch, so this patch is developed based on the mm-hotfixes-unstable branch. --- lib/alloc_tag.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c index 4ee6caa6d2da..f942408b53ef 100644 --- a/lib/alloc_tag.c +++ b/lib/alloc_tag.c @@ -424,6 +424,15 @@ static int vm_module_tags_populate(void) vm_module_tags->nr_pages +=3D nr; } =20 + /* + * Mark the pages as accessible, now that they are mapped. + * With hardware tag-based KASAN, marking is skipped for + * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc(). + */ + kasan_unpoison_vmalloc((void *)module_tags.start_addr, + new_end - module_tags.start_addr, + KASAN_VMALLOC_PROT_NORMAL); + return 0; } =20 --=20 2.25.1