[PATCH 4.14 105/165] scsi: qla2xxx: Avoid triggering undefined behavior in qla2x00_mbx_completion()

From: Greg Kroah-Hartman
Date: Thu May 24 2018 - 06:05:55 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Bart Van Assche <bart.vanassche@xxxxxxx>

[ Upstream commit c02189e12ce3bf3808cb880569d3b10249f50bd9 ]

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 <mroos@xxxxxxxx>
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
Cc: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
Reviewed-by: Laurence Oberman <loberman@xxxxxxxxxx>
Acked-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/qla2xxx/qla_isr.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- 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 *
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
@@ -2821,7 +2822,8 @@ qla24xx_mbx_completion(scsi_qla_host_t *
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