xhci: fix unsafe memory usage in xhci tracing

Removes static char buffer usage in the following decode functions:
	xhci_decode_trb()
	xhci_decode_ptortsc()

Caller must provide a buffer to use.
In tracing use __get_str() as recommended to pass buffer.

Minor chanes are needed in xhci debugfs code as these functions are also
used there. Changes include moving XHCI_MSG_MAX definititon from
xhci-trace.h to xhci.h

Cc: <stable@vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210820123503.2605901-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 28 insertions, 24 deletions

diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 3c7d281672ae..99ae9994f5eb 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -22,6 +22,9 @@
 #include	"xhci-ext-caps.h"
 #include "pci-quirks.h"
 
+/* max buffer size for trace and debug messages */
+#define XHCI_MSG_MAX		500
+
 /* xHCI PCI Configuration Registers */
 #define XHCI_SBRN_OFFSET	(0x60)
 
@@ -2235,15 +2238,14 @@ static inline char *xhci_slot_state_string(u32 state)
 	}
 }
 
-static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
-		u32 field3)
+static inline const char *xhci_decode_trb(char *str, size_t size,
+					  u32 field0, u32 field1, u32 field2, u32 field3)
 {
-	static char str[256];
 	int type = TRB_FIELD_TO_TYPE(field3);
 
 	switch (type) {
 	case TRB_LINK:
-		sprintf(str,
+		snprintf(str, size,
 			"LINK %08x%08x intr %d type '%s' flags %c:%c:%c:%c",
 			field1, field0, GET_INTR_TARGET(field2),
 			xhci_trb_type_string(type),
@@ -2260,7 +2262,7 @@ static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
 	case TRB_HC_EVENT:
 	case TRB_DEV_NOTE:
 	case TRB_MFINDEX_WRAP:
-		sprintf(str,
+		snprintf(str, size,
 			"TRB %08x%08x status '%s' len %d slot %d ep %d type '%s' flags %c:%c",
 			field1, field0,
 			xhci_trb_comp_code_string(GET_COMP_CODE(field2)),
@@ -2273,7 +2275,8 @@ static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
 
 		break;
 	case TRB_SETUP:
-		sprintf(str, "bRequestType %02x bRequest %02x wValue %02x%02x wIndex %02x%02x wLength %d length %d TD size %d intr %d type '%s' flags %c:%c:%c",
+		snprintf(str, size,
+			"bRequestType %02x bRequest %02x wValue %02x%02x wIndex %02x%02x wLength %d length %d TD size %d intr %d type '%s' flags %c:%c:%c",
 				field0 & 0xff,
 				(field0 & 0xff00) >> 8,
 				(field0 & 0xff000000) >> 24,
@@ -2290,7 +2293,8 @@ static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
 				field3 & TRB_CYCLE ? 'C' : 'c');
 		break;
 	case TRB_DATA:
-		sprintf(str, "Buffer %08x%08x length %d TD size %d intr %d type '%s' flags %c:%c:%c:%c:%c:%c:%c",
+		snprintf(str, size,
+			 "Buffer %08x%08x length %d TD size %d intr %d type '%s' flags %c:%c:%c:%c:%c:%c:%c",
 				field1, field0, TRB_LEN(field2), GET_TD_SIZE(field2),
 				GET_INTR_TARGET(field2),
 				xhci_trb_type_string(type),
@@ -2303,7 +2307,8 @@ static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
 				field3 & TRB_CYCLE ? 'C' : 'c');
 		break;
 	case TRB_STATUS:
-		sprintf(str, "Buffer %08x%08x length %d TD size %d intr %d type '%s' flags %c:%c:%c:%c",
+		snprintf(str, size,
+			 "Buffer %08x%08x length %d TD size %d intr %d type '%s' flags %c:%c:%c:%c",
 				field1, field0, TRB_LEN(field2), GET_TD_SIZE(field2),
 				GET_INTR_TARGET(field2),
 				xhci_trb_type_string(type),
@@ -2316,7 +2321,7 @@ static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
 	case TRB_ISOC:
 	case TRB_EVENT_DATA:
 	case TRB_TR_NOOP:
-		sprintf(str,
+		snprintf(str, size,
 			"Buffer %08x%08x length %d TD size %d intr %d type '%s' flags %c:%c:%c:%c:%c:%c:%c:%c",
 			field1, field0, TRB_LEN(field2), GET_TD_SIZE(field2),
 			GET_INTR_TARGET(field2),
@@ -2333,21 +2338,21 @@ static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
 
 	case TRB_CMD_NOOP:
 	case TRB_ENABLE_SLOT:
-		sprintf(str,
+		snprintf(str, size,
 			"%s: flags %c",
 			xhci_trb_type_string(type),
 			field3 & TRB_CYCLE ? 'C' : 'c');
 		break;
 	case TRB_DISABLE_SLOT:
 	case TRB_NEG_BANDWIDTH:
-		sprintf(str,
+		snprintf(str, size,
 			"%s: slot %d flags %c",
 			xhci_trb_type_string(type),
 			TRB_TO_SLOT_ID(field3),
 			field3 & TRB_CYCLE ? 'C' : 'c');
 		break;
 	case TRB_ADDR_DEV:
-		sprintf(str,
+		snprintf(str, size,
 			"%s: ctx %08x%08x slot %d flags %c:%c",
 			xhci_trb_type_string(type),
 			field1, field0,
@@ -2356,7 +2361,7 @@ static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
 			field3 & TRB_CYCLE ? 'C' : 'c');
 		break;
 	case TRB_CONFIG_EP:
-		sprintf(str,
+		snprintf(str, size,
 			"%s: ctx %08x%08x slot %d flags %c:%c",
 			xhci_trb_type_string(type),
 			field1, field0,
@@ -2365,7 +2370,7 @@ static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
 			field3 & TRB_CYCLE ? 'C' : 'c');
 		break;
 	case TRB_EVAL_CONTEXT:
-		sprintf(str,
+		snprintf(str, size,
 			"%s: ctx %08x%08x slot %d flags %c",
 			xhci_trb_type_string(type),
 			field1, field0,
@@ -2373,7 +2378,7 @@ static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
 			field3 & TRB_CYCLE ? 'C' : 'c');
 		break;
 	case TRB_RESET_EP:
-		sprintf(str,
+		snprintf(str, size,
 			"%s: ctx %08x%08x slot %d ep %d flags %c:%c",
 			xhci_trb_type_string(type),
 			field1, field0,
@@ -2394,7 +2399,7 @@ static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
 			field3 & TRB_CYCLE ? 'C' : 'c');
 		break;
 	case TRB_SET_DEQ:
-		sprintf(str,
+		snprintf(str, size,
 			"%s: deq %08x%08x stream %d slot %d ep %d flags %c",
 			xhci_trb_type_string(type),
 			field1, field0,
@@ -2405,14 +2410,14 @@ static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
 			field3 & TRB_CYCLE ? 'C' : 'c');
 		break;
 	case TRB_RESET_DEV:
-		sprintf(str,
+		snprintf(str, size,
 			"%s: slot %d flags %c",
 			xhci_trb_type_string(type),
 			TRB_TO_SLOT_ID(field3),
 			field3 & TRB_CYCLE ? 'C' : 'c');
 		break;
 	case TRB_FORCE_EVENT:
-		sprintf(str,
+		snprintf(str, size,
 			"%s: event %08x%08x vf intr %d vf id %d flags %c",
 			xhci_trb_type_string(type),
 			field1, field0,
@@ -2421,14 +2426,14 @@ static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
 			field3 & TRB_CYCLE ? 'C' : 'c');
 		break;
 	case TRB_SET_LT:
-		sprintf(str,
+		snprintf(str, size,
 			"%s: belt %d flags %c",
 			xhci_trb_type_string(type),
 			TRB_TO_BELT(field3),
 			field3 & TRB_CYCLE ? 'C' : 'c');
 		break;
 	case TRB_GET_BW:
-		sprintf(str,
+		snprintf(str, size,
 			"%s: ctx %08x%08x slot %d speed %d flags %c",
 			xhci_trb_type_string(type),
 			field1, field0,
@@ -2437,7 +2442,7 @@ static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
 			field3 & TRB_CYCLE ? 'C' : 'c');
 		break;
 	case TRB_FORCE_HEADER:
-		sprintf(str,
+		snprintf(str, size,
 			"%s: info %08x%08x%08x pkt type %d roothub port %d flags %c",
 			xhci_trb_type_string(type),
 			field2, field1, field0 & 0xffffffe0,
@@ -2446,7 +2451,7 @@ static inline const char *xhci_decode_trb(u32 field0, u32 field1, u32 field2,
 			field3 & TRB_CYCLE ? 'C' : 'c');
 		break;
 	default:
-		sprintf(str,
+		snprintf(str, size,
 			"type '%s' -> raw %08x %08x %08x %08x",
 			xhci_trb_type_string(type),
 			field0, field1, field2, field3);
@@ -2571,9 +2576,8 @@ static inline const char *xhci_portsc_link_state_string(u32 portsc)
 	return "Unknown";
 }
 
-static inline const char *xhci_decode_portsc(u32 portsc)
+static inline const char *xhci_decode_portsc(char *str, u32 portsc)
 {
-	static char str[256];
 	int ret;
 
 	ret = sprintf(str, "%s %s %s Link:%s PortSpeed:%d ",