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tun: avoid BUG, dump packet on GSO errors

PATCH Applied Michael S. Tsirkin 3 participants 3 messages Jul 21, 2010 – Jul 25, 2010

Subsystems (3)
Networking Network drivers TUN/TAP driver
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Michael S. Tsirkin

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#0 lore raw

PATCH 1/1 tun: avoid BUG, dump packet on GSO errors

There are still some LRO cards that cause GSO errors in tun, and BUG on this is an unfriendly way to tell the admin to disable LRO.

Further, experience shows we might have more GSO bugs lurking. See https://bugzilla.kernel.org/show_bug.cgi?id=16413
as a recent example.
dumping a packet will make it easier to figure it out.

Replace BUG with warning+dump+drop the packet to make GSO errors in tun less critical and easier to debug.

Signed-off-by Michael S. Tsirkin <[email protected]>
Tested-by Alex Unigovsky <[email protected]>

---

drivers/net/tun.c +12 -2
index 6ad6fe7..6304259 100644
@@ -736,8 +736,18 @@ static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
 				gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 			else if (sinfo->gso_type & SKB_GSO_UDP)
 				gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
-			else
-				BUG();
+			else {
+				printk(KERN_ERR "tun: unexpected GSO type: "
+				       "0x%x, gso_size %d, hdr_len %d\n",
+				       sinfo->gso_type, gso.gso_size,
+				       gso.hdr_len);
+				print_hex_dump(KERN_ERR, "tun: ",
+					       DUMP_PREFIX_NONE,
+					       16, 1, skb->head,
+					       min((int)gso.hdr_len, 64), true);
+				WARN_ON_ONCE(1);
+				return -EINVAL;
+			}
 			if (sinfo->gso_type & SKB_GSO_TCP_ECN)
 				gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 		} else
Acked-by on v1 1/1
#1 lore raw
Quoted 9 lines · Michael S. Tsirkin

There are still some LRO cards that cause GSO errors in tun, and BUG on this is an unfriendly way to tell the admin to disable LRO.

Further, experience shows we might have more GSO bugs lurking. See https://bugzilla.kernel.org/show_bug.cgi?id=16413
as a recent example.
dumping a packet will make it easier to figure it out.

Quoted 5 lines

Replace BUG with warning+dump+drop the packet to make GSO errors in tun less critical and easier to debug.

Signed-off-by Michael S. Tsirkin <[email protected]>
Tested-by Alex Unigovsky <[email protected]>
Acked-by Herbert Xu <[email protected]>
Signature · 3 lines
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
maintainer Applied
#2 lore raw

From: Herbert Xu <[email protected]>
Date: Thu, 22 Jul 2010 21:05:12 +0800

Quoted 10 lines
Quoted 9 lines · Michael S. Tsirkin

There are still some LRO cards that cause GSO errors in tun, and BUG on this is an unfriendly way to tell the admin to disable LRO.

Further, experience shows we might have more GSO bugs lurking. See https://bugzilla.kernel.org/show_bug.cgi?id=16413
as a recent example.
dumping a packet will make it easier to figure it out.

Quoted 7 lines
Quoted 5 lines

Replace BUG with warning+dump+drop the packet to make GSO errors in tun less critical and easier to debug.

Signed-off-by Michael S. Tsirkin <[email protected]>
Tested-by Alex Unigovsky <[email protected]>
Acked-by Herbert Xu <[email protected]>

Applied, thanks everyone.