drivers/misc/pch_phub.c: don't oops if dmi_get_system_info returns NULL

If dmi_get_system_info() returns NULL, pch_phub_probe() will dereferencea a zero pointer. This oops was observed on an Atom based board which has no BIOS, but a bootloder which doesn't privde DMI data. Signed-off-by: Alexander Stein <[email protected]> Cc: Tomoya MORINAGA <[email protected]> Cc: Greg KH <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
cbmeeks · Jul 26, 2011 · 2b934c6 · 2b934c6
1 parent 90b03f5
commit 2b934c6
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/drivers/misc/pch_phub.c b/drivers/misc/pch_phub.c
@@ -686,6 +686,8 @@ static int __devinit pch_phub_probe(struct pci_dev *pdev,
 	}
 
 	if (id->driver_data == 1) { /* EG20T PCH */
+		const char *board_name;
+
 		retval = sysfs_create_file(&pdev->dev.kobj,
 					   &dev_attr_pch_mac.attr);
 		if (retval)
@@ -701,7 +703,8 @@ static int __devinit pch_phub_probe(struct pci_dev *pdev,
 					       CLKCFG_CANCLK_MASK);
 
 		/* quirk for CM-iTC board */
-		if (strstr(dmi_get_system_info(DMI_BOARD_NAME), "CM-iTC"))
+		board_name = dmi_get_system_info(DMI_BOARD_NAME);
+		if (board_name && strstr(board_name, "CM-iTC"))
 			pch_phub_read_modify_write_reg(chip,
 						(unsigned int)CLKCFG_REG_OFFSET,
 						CLKCFG_UART_48MHZ | CLKCFG_BAUDDIV |