path: root/net
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authorEric Dumazet <edumazet@google.com>2013-05-13 21:25:52 +0000
committerDavid S. Miller <davem@davemloft.net>2013-05-14 11:32:04 -0700
commit54d27fcb338bd9c42d1dfc5a39e18f6f9d373c2e (patch)
treeb58af078897a29f931399b78d27655aea5c016a6 /net
parentefee8e8712921279c3a5a687d5b65ee7fde7db89 (diff)
tcp: fix tcp_md5_hash_skb_data()
TCP md5 communications fail [1] for some devices, because sg/crypto code assume page offsets are below PAGE_SIZE. This was discovered using mlx4 driver [2], but I suspect loopback might trigger the same bug now we use order-3 pages in tcp_sendmsg() [1] Failure is giving following messages. huh, entered softirq 3 NET_RX ffffffff806ad230 preempt_count 00000100, exited with 00000101? [2] mlx4 driver uses order-2 pages to allocate RX frags Reported-by: Matt Schnall <mischnal@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Bernhard Beck <bbeck@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
1 files changed, 5 insertions, 2 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index dcb116dde21..10c93930abd 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3269,8 +3269,11 @@ int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
for (i = 0; i < shi->nr_frags; ++i) {
const struct skb_frag_struct *f = &shi->frags[i];
- struct page *page = skb_frag_page(f);
- sg_set_page(&sg, page, skb_frag_size(f), f->page_offset);
+ unsigned int offset = f->page_offset;
+ struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT);
+ sg_set_page(&sg, page, skb_frag_size(f),
+ offset_in_page(offset));
if (crypto_hash_update(desc, &sg, skb_frag_size(f)))
return 1;