From: Masayoshi Mizuma <m.mizuma@xxxxxxxxxxxxxx> [ Upstream commit af31b04b67f4fd7f639fd465a507c154c46fc9fb ] KASAN reports following global out of bounds access while nfit_test is being loaded. The out of bound access happens the following reference to dimm_fail_cmd_flags[dimm]. 'dimm' is over than the index value, NUM_DCR (==5). static int override_return_code(int dimm, unsigned int func, int rc) { if ((1 << func) & dimm_fail_cmd_flags[dimm]) { dimm_fail_cmd_flags[] definition: static unsigned long dimm_fail_cmd_flags[NUM_DCR]; 'dimm' is the return value of get_dimm(), and get_dimm() returns the index of handle[] array. The handle[] has 7 index. Let's use ARRAY_SIZE(handle) as the array size. KASAN report: ================================================================== BUG: KASAN: global-out-of-bounds in nfit_test_ctl+0x47bb/0x55b0 [nfit_test] Read of size 8 at addr ffffffffc10cbbe8 by task kworker/u41:0/8 ... Call Trace: dump_stack+0xea/0x1b0 ? dump_stack_print_info.cold.0+0x1b/0x1b ? kmsg_dump_rewind_nolock+0xd9/0xd9 print_address_description+0x65/0x22e ? nfit_test_ctl+0x47bb/0x55b0 [nfit_test] kasan_report.cold.6+0x92/0x1a6 nfit_test_ctl+0x47bb/0x55b0 [nfit_test] ... The buggy address belongs to the variable: dimm_fail_cmd_flags+0x28/0xffffffffffffa440 [nfit_test] ================================================================== Fixes: 39611e83a28c ("tools/testing/nvdimm: Make DSM failure code injection...") Signed-off-by: Masayoshi Mizuma <m.mizuma@xxxxxxxxxxxxxx> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/testing/nvdimm/test/nfit.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c index cffc2c5a778d..ec50d2a95076 100644 --- a/tools/testing/nvdimm/test/nfit.c +++ b/tools/testing/nvdimm/test/nfit.c @@ -139,8 +139,8 @@ static u32 handle[] = { [6] = NFIT_DIMM_HANDLE(1, 0, 0, 0, 1), }; -static unsigned long dimm_fail_cmd_flags[NUM_DCR]; -static int dimm_fail_cmd_code[NUM_DCR]; +static unsigned long dimm_fail_cmd_flags[ARRAY_SIZE(handle)]; +static int dimm_fail_cmd_code[ARRAY_SIZE(handle)]; static const struct nd_intel_smart smart_def = { .flags = ND_INTEL_SMART_HEALTH_VALID @@ -203,7 +203,7 @@ struct nfit_test { unsigned long deadline; spinlock_t lock; } ars_state; - struct device *dimm_dev[NUM_DCR]; + struct device *dimm_dev[ARRAY_SIZE(handle)]; struct nd_intel_smart *smart; struct nd_intel_smart_threshold *smart_threshold; struct badrange badrange; @@ -2678,7 +2678,7 @@ static int nfit_test_probe(struct platform_device *pdev) u32 nfit_handle = __to_nfit_memdev(nfit_mem)->device_handle; int i; - for (i = 0; i < NUM_DCR; i++) + for (i = 0; i < ARRAY_SIZE(handle); i++) if (nfit_handle == handle[i]) dev_set_drvdata(nfit_test->dimm_dev[i], nfit_mem); -- 2.17.1