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USB speedtouch: discard packets for non-existant vcc's

PATCH Applied Duncan Sands 2 participants 2 messages Apr 12, 2003 – Apr 15, 2003 USB

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Duncan Sands

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#0 lore raw

PATCH 1/1 USB speedtouch: discard packets for non-existant vcc's

I broke part of the udsl_decode_rawcell logic in a previous patch, leading to possible hangs on startup/shutdown. I've attached the 2.4 and 2.5 versions. Thanks to Subodh Srivastava and Ted Phelps for their bug reports. Here is the 2.5 patch included inline for reference:

drivers/usb/misc/speedtch.c +5 -4
@@ -278,9 +278,10 @@
 
 		/* here should the header CRC check be... */
 
-		if (!(vcc = udsl_find_vcc (instance, vpi, vci)))
+		if (!(vcc = udsl_find_vcc (instance, vpi, vci))) {
 			dbg ("udsl_decode_rawcell: no vcc found for packet on vpi %d, vci %d", vpi, vci);
-		else {
+			__skb_pull (skb, min (skb->len, (unsigned) 53));
+		} else {
 			dbg ("udsl_decode_rawcell found vcc %p for packet on vpi %d, vci %d", vcc, vpi, vci);
 
 			if (skb->len >= 53) {

@@ -323,8 +324,8 @@
 				skb_pull (skb, 53);
 			} else {
 				/* If data is corrupt and skb doesn't hold a whole cell, flush the lot */
-				if (skb_pull (skb, 53) == NULL)
-					return NULL;
+				__skb_pull (skb, skb->len);
+				return NULL;
 			}
 		}
 	}
drivers/usb/speedtouch.c +5 -4
@@ -278,9 +278,10 @@
 
 		/* here should the header CRC check be... */
 
-		if (!(vcc = udsl_find_vcc (instance, vpi, vci)))
+		if (!(vcc = udsl_find_vcc (instance, vpi, vci))) {
 			dbg ("udsl_decode_rawcell: no vcc found for packet on vpi %d, vci %d", vpi, vci);
-		else {
+			__skb_pull (skb, min (skb->len, (unsigned) 53));
+		} else {
 			dbg ("udsl_decode_rawcell found vcc %p for packet on vpi %d, vci %d", vcc, vpi, vci);
 
 			if (skb->len >= 53) {

@@ -323,8 +324,8 @@
 				skb_pull (skb, 53);
 			} else {
 				/* If data is corrupt and skb doesn't hold a whole cell, flush the lot */
-				if (skb_pull (skb, 53) == NULL)
-					return NULL;
+				__skb_pull (skb, skb->len);
+				return NULL;
 			}
 		}
 	}
drivers/usb/misc/speedtch.c +5 -4
@@ -278,9 +278,10 @@
 
 		/* here should the header CRC check be... */
 
-		if (!(vcc = udsl_find_vcc (instance, vpi, vci)))
+		if (!(vcc = udsl_find_vcc (instance, vpi, vci))) {
 			dbg ("udsl_decode_rawcell: no vcc found for packet on vpi %d, vci %d", vpi, vci);
-		else {
+			__skb_pull (skb, min (skb->len, (unsigned) 53));
+		} else {
 			dbg ("udsl_decode_rawcell found vcc %p for packet on vpi %d, vci %d", vcc, vpi, vci);
 
 			if (skb->len >= 53) {

@@ -323,8 +324,8 @@
 				skb_pull (skb, 53);
 			} else {
 				/* If data is corrupt and skb doesn't hold a whole cell, flush the lot */
-				if (skb_pull (skb, 53) == NULL)
-					return NULL;
+				__skb_pull (skb, skb->len);
+				return NULL;
 			}
 		}
 	}
Applied
#1 lore raw
Quoted 4 lines · Duncan Sands

I broke part of the udsl_decode_rawcell logic in a previous patch, leading to possible hangs on startup/shutdown. I've attached the 2.4 and 2.5 versions. Thanks to Subodh Srivastava and Ted Phelps for their bug reports. Here is the 2.5 patch included inline for reference:

Applied to my 2.4 and 2.5 trees, thanks.

greg k-h