[no subject]

[Qian Cai]

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