From: Alexander Lobakin <alexandr.lobakin@intel.com>
To: Yury Norov <yury.norov@gmail.com>, David Woodhouse <dwmw2@infradead.org>
Cc: Alexander Lobakin <alexandr.lobakin@intel.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Lu Baolu <baolu.lu@linux.intel.com>,
Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
Suresh Siddha <suresh.b.siddha@intel.com>,
kernel test robot <oliver.sang@intel.com>,
iommu@lists.linux.dev, stable@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iommu/vt-d: avoid invalid memory access via node_online(NUMA_NO_NODE)
Date: Tue, 12 Jul 2022 17:44:07 +0200 [thread overview]
Message-ID: <20220712154407.42196-1-alexandr.lobakin@intel.com> (raw)
In-Reply-To: <20220712153836.41599-1-alexandr.lobakin@intel.com>
From: Alexander Lobakin <alexandr.lobakin@intel.com>
Date: Tue, 12 Jul 2022 17:38:36 +0200
> KASAN reports:
>
> [ 4.668325][ T0] BUG: KASAN: wild-memory-access in dmar_parse_one_rhsa (arch/x86/include/asm/bitops.h:214 arch/x86/include/asm/bitops.h:226 include/asm-generic/bitops/instrumented-non-atomic.h:142 include/linux/nodemask.h:415 drivers/iommu/intel/dmar.c:497)
> [ 4.676149][ T0] Read of size 8 at addr 1fffffff85115558 by task swapper/0/0
> [ 4.683454][ T0]
> [ 4.685638][ T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.19.0-rc3-00004-g0e862838f290 #1
> [ 4.694331][ T0] Hardware name: Supermicro SYS-5018D-FN4T/X10SDV-8C-TLN4F, BIOS 1.1 03/02/2016
> [ 4.703196][ T0] Call Trace:
> [ 4.706334][ T0] <TASK>
> [ 4.709133][ T0] ? dmar_parse_one_rhsa (arch/x86/include/asm/bitops.h:214 arch/x86/include/asm/bitops.h:226 include/asm-generic/bitops/instrumented-non-atomic.h:142 include/linux/nodemask.h:415 drivers/iommu/intel/dmar.c:497)
>
> after converting the type of the first argument (@nr, bit number)
> of arch_test_bit() from `long` to `unsigned long`[0].
>
> Under certain conditions (for example, when ACPI NUMA is disabled
> via command line), pxm_to_node() can return %NUMA_NO_NODE (-1).
> It is valid 'magic' number of NUMA node, but not valid bit number
> to use in bitops.
> node_online() eventually descends to test_bit() without checking
> for the input, assuming it's on caller side (which might be good
> for perf-critical tasks). There, -1 becomes %ULONG_MAX which leads
> to an insane array index when calculating bit position in memory.
>
> For now, add an explicit check for @node being not %NUMA_NO_NODE
> before calling test_bit(). The actual logics didn't change here
> at all.
Bah, forgot to insert the link here. Hope not worth resending ._.
[0] https://github.com/norov/linux/commit/0e862838f290147ea9c16db852d8d494b552d38d
>
> Fixes: ee34b32d8c29 ("dmar: support for parsing Remapping Hardware Static Affinity structure")
> Cc: stable@vger.kernel.org # 2.6.33+
> Reported-by: kernel test robot <oliver.sang@intel.com>
> Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
> ---
> drivers/iommu/intel/dmar.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
> index 9699ca101c62..64b14ac4c7b0 100644
> --- a/drivers/iommu/intel/dmar.c
> +++ b/drivers/iommu/intel/dmar.c
> @@ -494,7 +494,7 @@ static int dmar_parse_one_rhsa(struct acpi_dmar_header *header, void *arg)
> if (drhd->reg_base_addr == rhsa->base_address) {
> int node = pxm_to_node(rhsa->proximity_domain);
>
> - if (!node_online(node))
> + if (node != NUMA_NO_NODE && !node_online(node))
> node = NUMA_NO_NODE;
> drhd->iommu->node = node;
> return 0;
> --
> 2.36.1
Thanks,
Olek
next prev parent reply other threads:[~2022-07-12 15:45 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-12 15:38 [PATCH] iommu/vt-d: avoid invalid memory access via node_online(NUMA_NO_NODE) Alexander Lobakin
2022-07-12 15:44 ` Alexander Lobakin [this message]
2022-07-12 15:54 ` Yury Norov
2022-07-13 0:02 ` Baolu Lu
2022-07-12 16:00 ` Andy Shevchenko
2022-07-13 16:13 ` Yury Norov
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