linux-kernel - Re: [PATCH v4 13/18] kasan: arm64: x86: Handle int3 for inline KASAN reports

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <34sbzdtnh74bbkg6yopytxn553efynrjp3nylnx6hg4sgwsder@zff244djrxe2>
Date: Mon, 18 Aug 2025 07:57:08 +0200
From: Maciej Wieczor-Retman <maciej.wieczor-retman@...el.com>
To: Ada Couprie Diaz <ada.coupriediaz@....com>
CC: <nathan@...nel.org>, <arnd@...db.de>, <broonie@...nel.org>,
	<Liam.Howlett@...cle.com>, <urezki@...il.com>, <will@...nel.org>,
	<kaleshsingh@...gle.com>, <rppt@...nel.org>, <leitao@...ian.org>,
	<coxu@...hat.com>, <surenb@...gle.com>, <akpm@...ux-foundation.org>,
	<luto@...nel.org>, <jpoimboe@...nel.org>, <changyuanl@...gle.com>,
	<hpa@...or.com>, <dvyukov@...gle.com>, <kas@...nel.org>, <corbet@....net>,
	<vincenzo.frascino@....com>, <smostafa@...gle.com>,
	<nick.desaulniers+lkml@...il.com>, <morbo@...gle.com>,
	<andreyknvl@...il.com>, <alexander.shishkin@...ux.intel.com>,
	<thiago.bauermann@...aro.org>, <catalin.marinas@....com>,
	<ryabinin.a.a@...il.com>, <jan.kiszka@...mens.com>, <jbohac@...e.cz>,
	<dan.j.williams@...el.com>, <joel.granados@...nel.org>, <baohua@...nel.org>,
	<kevin.brodsky@....com>, <nicolas.schier@...ux.dev>, <pcc@...gle.com>,
	<andriy.shevchenko@...ux.intel.com>, <wei.liu@...nel.org>, <bp@...en8.de>,
	<xin@...or.com>, <pankaj.gupta@....com>, <vbabka@...e.cz>,
	<glider@...gle.com>, <jgross@...e.com>, <kees@...nel.org>,
	<jhubbard@...dia.com>, <joey.gouly@....com>, <ardb@...nel.org>,
	<thuth@...hat.com>, <pasha.tatashin@...een.com>,
	<kristina.martsenko@....com>, <bigeasy@...utronix.de>,
	<lorenzo.stoakes@...cle.com>, <jason.andryuk@....com>, <david@...hat.com>,
	<graf@...zon.com>, <wangkefeng.wang@...wei.com>, <ziy@...dia.com>,
	<mark.rutland@....com>, <dave.hansen@...ux.intel.com>,
	<samuel.holland@...ive.com>, <kbingham@...nel.org>,
	<trintaeoitogc@...il.com>, <scott@...amperecomputing.com>,
	<justinstitt@...gle.com>, <kuan-ying.lee@...onical.com>, <maz@...nel.org>,
	<tglx@...utronix.de>, <samitolvanen@...gle.com>, <mhocko@...e.com>,
	<nunodasneves@...ux.microsoft.com>, <brgerst@...il.com>,
	<willy@...radead.org>, <ubizjak@...il.com>, <peterz@...radead.org>,
	<mingo@...hat.com>, <sohil.mehta@...el.com>, <linux-mm@...ck.org>,
	<linux-kbuild@...r.kernel.org>, <linux-arm-kernel@...ts.infradead.org>,
	<x86@...nel.org>, <llvm@...ts.linux.dev>, <kasan-dev@...glegroups.com>,
	<linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v4 13/18] kasan: arm64: x86: Handle int3 for inline KASAN
 reports

On 2025-08-13 at 15:49:15 +0100, Ada Couprie Diaz wrote:
>Hi,
>
>On 12/08/2025 14:23, Maciej Wieczor-Retman wrote:
>> [...]
>> 
>> Make part of that hook - which decides whether to die or recover from a
>> tag mismatch - arch independent to avoid duplicating a long comment on
>> both x86 and arm64 architectures.
>> 
>> Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@...el.com>
>> ---
>> [...]
>> diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
>> index f528b6041f6a..b9bdabc14ad1 100644
>> --- a/arch/arm64/kernel/traps.c
>> +++ b/arch/arm64/kernel/traps.c
>> @@ -1068,22 +1068,7 @@ int kasan_brk_handler(struct pt_regs *regs, unsigned long esr)
>>   	kasan_report(addr, size, write, pc);
>> -	/*
>> -	 * The instrumentation allows to control whether we can proceed after
>> -	 * a crash was detected. This is done by passing the -recover flag to
>> -	 * the compiler. Disabling recovery allows to generate more compact
>> -	 * code.
>> -	 *
>> -	 * Unfortunately disabling recovery doesn't work for the kernel right
>> -	 * now. KASAN reporting is disabled in some contexts (for example when
>> -	 * the allocator accesses slab object metadata; this is controlled by
>> -	 * current->kasan_depth). All these accesses are detected by the tool,
>> -	 * even though the reports for them are not printed.
>> -	 *
>> -	 * This is something that might be fixed at some point in the future.
>> -	 */
>> -	if (!recover)
>> -		die("Oops - KASAN", regs, esr);
>> +	kasan_inline_recover(recover, "Oops - KASAN", regs, esr);
>It seems that `die` is missing as the last argument, otherwise
>CONFIG_KASAN_SW_TAGS will not build on arm64.
>With the fix, it builds fully without further issues.
>
>Thanks,
>Ada

Oh right, thank you!

-- 
Kind regards
Maciej Wieczór-Retman