From: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx> 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@xxxxxxxxxxxxxxx # 2.6.33+ > Reported-by: kernel test robot <oliver.sang@xxxxxxxxx> > Signed-off-by: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx> > --- > 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
