From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurence Oberman Subject: Re: [PATCH] qla2xxx: Avoid triggering undefined behavior in qla2x00_mbx_completion() Date: Thu, 25 Jan 2018 11:55:34 -0500 Message-ID: <1516899334.5545.1.camel@redhat.com> References: <20180125162429.7962-1-bart.vanassche@wdc.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Return-path: Received: from mail-qt0-f196.google.com ([209.85.216.196]:33676 "EHLO mail-qt0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750992AbeAYQzh (ORCPT ); Thu, 25 Jan 2018 11:55:37 -0500 Received: by mail-qt0-f196.google.com with SMTP id d8so20875468qtm.0 for ; Thu, 25 Jan 2018 08:55:37 -0800 (PST) In-Reply-To: <20180125162429.7962-1-bart.vanassche@wdc.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Bart Van Assche , "Martin K . Petersen" , "James E . J . Bottomley" Cc: linux-scsi@vger.kernel.org, Himanshu Madhani On Thu, 2018-01-25 at 08:24 -0800, Bart Van Assche wrote: > A left shift must shift less than the bit width of the left argument. > Avoid triggering undefined behavior if ha->mbx_count == 32. > > This patch avoids that UBSAN reports the following complaint: > > UBSAN: Undefined behaviour in drivers/scsi/qla2xxx/qla_isr.c:275:14 > shift exponent 32 is too large for 32-bit type 'int' > Call Trace: >  dump_stack+0x4e/0x6c >  ubsan_epilogue+0xd/0x3b >  __ubsan_handle_shift_out_of_bounds+0x112/0x14c >  qla2x00_mbx_completion+0x1c5/0x25d [qla2xxx] >  qla2300_intr_handler+0x1ea/0x3bb [qla2xxx] >  qla2x00_mailbox_command+0x77b/0x139a [qla2xxx] >  qla2x00_mbx_reg_test+0x83/0x114 [qla2xxx] >  qla2x00_chip_diag+0x354/0x45f [qla2xxx] >  qla2x00_initialize_adapter+0x2c2/0xa4e [qla2xxx] >  qla2x00_probe_one+0x1681/0x392e [qla2xxx] >  pci_device_probe+0x10b/0x1f1 >  driver_probe_device+0x21f/0x3a4 >  __driver_attach+0xa9/0xe1 >  bus_for_each_dev+0x6e/0xb5 >  driver_attach+0x22/0x3c >  bus_add_driver+0x1d1/0x2ae >  driver_register+0x78/0x130 >  __pci_register_driver+0x75/0xa8 >  qla2x00_module_init+0x21b/0x267 [qla2xxx] >  do_one_initcall+0x5a/0x1e2 >  do_init_module+0x9d/0x285 >  load_module+0x20db/0x38e3 >  SYSC_finit_module+0xa8/0xbc >  SyS_finit_module+0x9/0xb >  do_syscall_64+0x77/0x271 >  entry_SYSCALL64_slow_path+0x25/0x25 > > Reported-by: Meelis Roos > Signed-off-by: Bart Van Assche > Cc: Himanshu Madhani > --- >  drivers/scsi/qla2xxx/qla_isr.c | 6 ++++-- >  1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/scsi/qla2xxx/qla_isr.c > b/drivers/scsi/qla2xxx/qla_isr.c > index 16c43bd9bb83..79f538448364 100644 > --- a/drivers/scsi/qla2xxx/qla_isr.c > +++ b/drivers/scsi/qla2xxx/qla_isr.c > @@ -272,7 +272,8 @@ qla2x00_mbx_completion(scsi_qla_host_t *vha, > uint16_t mb0) >   struct device_reg_2xxx __iomem *reg = &ha->iobase->isp; >   >   /* Read all mbox registers? */ > - mboxes = (1 << ha->mbx_count) - 1; > + WARN_ON_ONCE(ha->mbx_count > 32); > + mboxes = (1ULL << ha->mbx_count) - 1; >   if (!ha->mcp) >   ql_dbg(ql_dbg_async, vha, 0x5001, "MBX pointer > ERROR.\n"); >   else > @@ -2884,7 +2885,8 @@ qla24xx_mbx_completion(scsi_qla_host_t *vha, > uint16_t mb0) >   struct device_reg_24xx __iomem *reg = &ha->iobase->isp24; >   >   /* Read all mbox registers? */ > - mboxes = (1 << ha->mbx_count) - 1; > + WARN_ON_ONCE(ha->mbx_count > 32); > + mboxes = (1ULL << ha->mbx_count) - 1; >   if (!ha->mcp) >   ql_dbg(ql_dbg_async, vha, 0x504e, "MBX pointer > ERROR.\n"); >   else This looks fine to me and I tested the earlier patch suggestion supplied by Meelis. Reviewed-by: Laurence Oberman