Bcc: Subject: UBSAN: array-index-out-of-bounds in drivers/scsi/hpsa.c:4421:7 Reply-To: The commit 64ce60cab246 ("hpsa: correct skipping masked peripherals") trigger an UBSAN warning below. When i == 0 in hpsa_update_scsi_devices(), for (i = 0; i < nphysicals + nlogicals + 1; i++) { ... int phys_dev_index = i - (raid_ctlr_position == 0); It ends up calling LUN[-1]. &physdev_list->LUN[phys_dev_index] Should there by a test of underflow to set phys_dev_index == 0 in this case? [ 118.395557][ T13] hpsa can't handle SMP requests [ 118.444870][ T13] ================================================================================ [ 118.486725][ T13] UBSAN: array-index-out-of-bounds in drivers/scsi/hpsa.c:4421:7 [ 118.521606][ T13] index -1 is out of range for type 'struct ext_report_lun_entry [1024]' [ 118.559481][ T13] CPU: 0 PID: 13 Comm: kworker/0:1 Not tainted 5.7.0-rc6-next-20200522+ #3 [ 118.598179][ T13] Hardware name: HP ProLiant BL660c Gen9, BIOS I38 10/17/2018 [ 118.632882][ T13] Workqueue: events work_for_cpu_fn [ 118.656492][ T13] Call Trace: [ 118.670899][ T13] dump_stack+0x10b/0x17f [ 118.690216][ T13] __ubsan_handle_out_of_bounds+0xd2/0x110 [ 118.712593][ T378] bnx2x 0000:41:00.1: 63.008 Gb/s available PCIe bandwidth (8.0 GT/s PCIe x8 link) [ 118.716249][ T13] hpsa_update_scsi_devices+0x28e3/0x2cc0 [hpsa] [ 118.786774][ T13] hpsa_scan_start+0x228/0x260 [hpsa] [ 118.810663][ T13] ? _raw_spin_unlock_irqrestore+0x6a/0x80 [ 118.836529][ T13] do_scsi_scan_host+0x8a/0x110 [ 118.858104][ T13] scsi_scan_host+0x222/0x280 [ 118.879287][ T13] ? hpsa_scsi_do_inquiry+0xcd/0xe0 [hpsa] [ 118.907707][ T13] hpsa_init_one+0x1b79/0x27c0 [hpsa] [ 118.934818][ T13] ? hpsa_find_device_by_sas_rphy+0xd0/0xd0 [hpsa] [ 118.964279][ T13] local_pci_probe+0x82/0xe0 [ 118.985405][ T13] ? pci_name+0x70/0x70 [ 119.004244][ T13] work_for_cpu_fn+0x3a/0x60 [ 119.024672][ T13] process_one_work+0x49f/0x8f0 [ 119.046431][ T13] process_scheduled_works+0x72/0xa0 [ 119.069906][ T13] worker_thread+0x463/0x5b0 [ 119.090347][ T13] kthread+0x21d/0x240 [ 119.108531][ T13] ? pr_cont_work+0xa0/0xa0 [ 119.128450][ T13] ? __write_once_size+0x30/0x30 [ 119.150405][ T13] ret_from_fork+0x27/0x40