On Tue, Jul 12, 2022 at 8:45 AM Alexander Lobakin <alexandr.lobakin@xxxxxxxxx> wrote: > > 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 I'll add this link and apply the patch to the bitmap-for-next, after some testing. Thanks, Yury
