The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b0b0b77ea611e3088e9523e60860f4f41b62b235 Mon Sep 17 00:00:00 2001 From: Alexander Lobakin alexandr.lobakin@intel.com Date: Tue, 12 Jul 2022 17:38:36 +0200 Subject: [PATCH] iommu/vt-d: avoid invalid memory access via node_online(NUMA_NO_NODE)
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.
[0] https://github.com/norov/linux/commit/0e862838f290147ea9c16db852d8d494b552d3...
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 Reviewed-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Reviewed-by: Lu Baolu baolu.lu@linux.intel.com Signed-off-by: Yury Norov yury.norov@gmail.com
diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c index 592c1e1a5d4b..70d324c9894a 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;