On Thu, Dec 13, 2018 at 6:57 PM Qian Cai <cai@xxxxxx> wrote:
>
> UBSAN reported those with MegaRAID SAS-3 3108,
>
> [ 77.467308] UBSAN: Undefined behaviour in drivers/scsi/megaraid/megaraid_sas_fp.c:117:32
> [ 77.475402] index 255 is out of range for type 'MR_LD_SPAN_MAP [1]'
> [ 77.481677] CPU: 16 PID: 333 Comm: kworker/16:1 Not tainted 4.20.0-rc5+ #1
> [ 77.488556] Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.50 06/01/2018
> [ 77.495791] Workqueue: events work_for_cpu_fn
> [ 77.500154] Call trace:
> [ 77.502610] dump_backtrace+0x0/0x2c8
> [ 77.506279] show_stack+0x24/0x30
> [ 77.509604] dump_stack+0x118/0x19c
> [ 77.513098] ubsan_epilogue+0x14/0x60
> [ 77.516765] __ubsan_handle_out_of_bounds+0xfc/0x13c
> [ 77.521767] mr_update_load_balance_params+0x150/0x158 [megaraid_sas]
> [ 77.528230] MR_ValidateMapInfo+0x2cc/0x10d0 [megaraid_sas]
> [ 77.533825] megasas_get_map_info+0x244/0x2f0 [megaraid_sas]
> [ 77.539505] megasas_init_adapter_fusion+0x9b0/0xf48 [megaraid_sas]
> [ 77.545794] megasas_init_fw+0x1ab4/0x3518 [megaraid_sas]
> [ 77.551212] megasas_probe_one+0x2c4/0xbe0 [megaraid_sas]
> [ 77.556614] local_pci_probe+0x7c/0xf0
> [ 77.560365] work_for_cpu_fn+0x34/0x50
> [ 77.564118] process_one_work+0x61c/0xf08
> [ 77.568129] worker_thread+0x534/0xa70
> [ 77.571882] kthread+0x1c8/0x1d0
> [ 77.575114] ret_from_fork+0x10/0x1c
>
> [ 89.240332] UBSAN: Undefined behaviour in drivers/scsi/megaraid/megaraid_sas_fp.c:117:32
> [ 89.248426] index 255 is out of range for type 'MR_LD_SPAN_MAP [1]'
> [ 89.254700] CPU: 16 PID: 95 Comm: kworker/u130:0 Not tainted 4.20.0-rc5+ #1
> [ 89.261665] Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.50 06/01/2018
> [ 89.268903] Workqueue: events_unbound async_run_entry_fn
> [ 89.274222] Call trace:
> [ 89.276680] dump_backtrace+0x0/0x2c8
> [ 89.280348] show_stack+0x24/0x30
> [ 89.283671] dump_stack+0x118/0x19c
> [ 89.287167] ubsan_epilogue+0x14/0x60
> [ 89.290835] __ubsan_handle_out_of_bounds+0xfc/0x13c
> [ 89.295828] MR_LdRaidGet+0x50/0x58 [megaraid_sas]
> [ 89.300638] megasas_build_io_fusion+0xbb8/0xd90 [megaraid_sas]
> [ 89.306576] megasas_build_and_issue_cmd_fusion+0x138/0x460 [megaraid_sas]
> [ 89.313468] megasas_queue_command+0x398/0x3d0 [megaraid_sas]
> [ 89.319222] scsi_dispatch_cmd+0x1dc/0x8a8
> [ 89.323321] scsi_request_fn+0x8e8/0xdd0
> [ 89.327249] __blk_run_queue+0xc4/0x158
> [ 89.331090] blk_execute_rq_nowait+0xf4/0x158
> [ 89.335449] blk_execute_rq+0xdc/0x158
> [ 89.339202] __scsi_execute+0x130/0x258
> [ 89.343041] scsi_probe_and_add_lun+0x2fc/0x1488
> [ 89.347661] __scsi_scan_target+0x1cc/0x8c8
> [ 89.351848] scsi_scan_channel.part.3+0x8c/0xc0
> [ 89.356382] scsi_scan_host_selected+0x130/0x1f0
> [ 89.361002] do_scsi_scan_host+0xd8/0xf0
> [ 89.364927] do_scan_async+0x9c/0x320
> [ 89.368594] async_run_entry_fn+0x138/0x420
> [ 89.372780] process_one_work+0x61c/0xf08
> [ 89.376793] worker_thread+0x13c/0xa70
> [ 89.380546] kthread+0x1c8/0x1d0
> [ 89.383778] ret_from_fork+0x10/0x1c
>
> This is because when populating Driver Map using firmware raid map, all
> non-existing VDs set their ldTgtIdToLd to 0xff, so it can be skipped
> later.
>
> From drivers/scsi/megaraid/megaraid_sas_base.c ,
> memset(instance->ld_ids, 0xff, MEGASAS_MAX_LD_IDS);
>
> From drivers/scsi/megaraid/megaraid_sas_fp.c ,
> /* For non existing VDs, iterate to next VD*/
> if (ld >= (MAX_LOGICAL_DRIVES_EXT - 1))
> continue;
>
> However, there are a few places that failed to skip those non-existing
> VDs due to off-by-one errors. Then, those 0xff leaked into
> MR_LdRaidGet(0xff, map) and triggered the out-of-bound accesses.
>
> Fixes: 51087a8617fe (megaraid_sas : Extended VD support)
> Signed-off-by: Qian Cai <cai@xxxxxx>
Acked-by: Sumit Saxena <sumit.saxena@xxxxxxxxxxxx>
> ---
> drivers/scsi/megaraid/megaraid_sas_fp.c | 2 +-
> drivers/scsi/megaraid/megaraid_sas_fusion.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/megaraid/megaraid_sas_fp.c b/drivers/scsi/megaraid/megaraid_sas_fp.c
> index 59ecbb3b53b5..a33628550425 100644
> --- a/drivers/scsi/megaraid/megaraid_sas_fp.c
> +++ b/drivers/scsi/megaraid/megaraid_sas_fp.c
> @@ -1266,7 +1266,7 @@ void mr_update_load_balance_params(struct MR_DRV_RAID_MAP_ALL *drv_map,
>
> for (ldCount = 0; ldCount < MAX_LOGICAL_DRIVES_EXT; ldCount++) {
> ld = MR_TargetIdToLdGet(ldCount, drv_map);
> - if (ld >= MAX_LOGICAL_DRIVES_EXT) {
> + if (ld >= MAX_LOGICAL_DRIVES_EXT - 1) {
> lbInfo[ldCount].loadBalanceFlag = 0;
> continue;
> }
> diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
> index f74b5ea24f0f..49eaa87608f6 100644
> --- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
> +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
> @@ -2832,7 +2832,7 @@ static void megasas_build_ld_nonrw_fusion(struct megasas_instance *instance,
> device_id < instance->fw_supported_vd_count)) {
>
> ld = MR_TargetIdToLdGet(device_id, local_map_ptr);
> - if (ld >= instance->fw_supported_vd_count)
> + if (ld >= instance->fw_supported_vd_count - 1)
> fp_possible = 0;
> else {
> raid = MR_LdRaidGet(ld, local_map_ptr);
> --
> 2.17.2 (Apple Git-113)
>
